U.S. patent application number 17/075374 was filed with the patent office on 2021-02-11 for dry citrus fibers and uses thereof.
The applicant listed for this patent is Cargill, Incorporated. Invention is credited to Gerrit Jan Wilem Goudappel, Hendrikus Theodorus Wilhelmus Maria Van Der Hijden, Ivo Kohls, Jacques Andre Christian Mazoyer, Asier Rodriguez, Krassimir Petkov Velikov.
Application Number | 20210037874 17/075374 |
Document ID | / |
Family ID | 1000005168666 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210037874 |
Kind Code |
A1 |
Goudappel; Gerrit Jan Wilem ;
et al. |
February 11, 2021 |
DRY CITRUS FIBERS AND USES THEREOF
Abstract
The invention relates to citrus fibers in dry form having a
storage modulus (G')of at least 50 Pa, said G' being measured on an
aqueous medium containing an amount of 2 wt % citrus fibers
dispersed therein under a low-shear stirring of less than 1000
rpm.
Inventors: |
Goudappel; Gerrit Jan Wilem;
(Vlaardingen, NL) ; Hijden; Hendrikus Theodorus Wilhelmus
Maria Van Der; (Vlaardingen, NL) ; Kohls; Ivo;
(Malchin, DE) ; Rodriguez; Asier; (Vilvoorde,
BE) ; Velikov; Krassimir Petkov; (Vlaardingen,
NL) ; Mazoyer; Jacques Andre Christian; (Carentan,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cargill, Incorporated |
Wayzata |
MN |
US |
|
|
Family ID: |
1000005168666 |
Appl. No.: |
17/075374 |
Filed: |
October 20, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15748781 |
Jan 30, 2018 |
10834953 |
|
|
PCT/US2016/044226 |
Jul 27, 2016 |
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17075374 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23L 19/07 20160801;
A23L 2/52 20130101; A23L 33/22 20160801; A23F 3/163 20130101; A23L
33/105 20160801; A61K 36/752 20130101; A23P 10/40 20160801; C11D
3/382 20130101 |
International
Class: |
A23L 33/22 20060101
A23L033/22; A23L 2/52 20060101 A23L002/52; C11D 3/382 20060101
C11D003/382; A23P 10/40 20060101 A23P010/40; A23L 19/00 20060101
A23L019/00; A23F 3/16 20060101 A23F003/16; A23L 33/105 20060101
A23L033/105; A61K 36/752 20060101 A61K036/752 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 30, 2015 |
EP |
15178987.2 |
Claims
1-15. (canceled)
16. Cellulose fibers in dry form having a Fiber Availability
Parameter ("FAP") of at least 0.35 Hz and comprising an additive
distributed between said fibers.
17. The cellulose fibers of claim 16, said cellulose fibers in dry
form having a FAP of at least 0.37 Hz.
18. The cellulose fibers of claim 16, said cellulose fibers in dry
form having a FAP of at most 5.0 Hz.
19. The cellulose fibers of claim 18, said cellulose fibers in dry
form having a FAP of at most 3.0 Hz.
20. The cellulose fibers of claim 19, said cellulose fibers in dry
form having a FAP of at most 2.0 Hz.
21. The cellulose fibers of claim 16, said cellulose fibers in dry
form are citrus fibers in dry form.
22. The cellulose fibers of claim 16, wherein the cellulose fibers
in dry form have a moisture content of at most 12 wt. %.
23. The cellulose fibers of claim 16, wherein said cellulose fibers
in dry form are derived from at least one of oranges, sweet
oranges, clementines, kumquats, tangerines, tangelos, satsumas,
mandarins, grapefruits, citrons, pomelos, lemons, rough lemons,
limes, and leech limes.
24. The cellulose fibers of claim 16, wherein said cellulose fibers
in dry form are derived from at least one of early-season,
mid-season, and late-season citrus fruit.
25. The cellulose fibers of claim 16, wherein said cellulose fibers
in dry form are derived from at least one of citrus peel, citrus
pulp, and citrus rag.
26. The cellulose fibers of claim 16, wherein said cellulose fibers
in dry form are not subjected to at lease one of esterification,
derivatisation, and enzymatic modification.
27. The cellulose fibers of claim 16, wherein the cellulose fibers
in dry form comprise at least 5 wt. % additive relative to the
weight of the cellulose fibers in dry form.
28. The cellulose fibers of claim 16, wherein the additive to
cellulose fibers in dry form ratio is between 0.01:1.0 and 10.0:1.0
by weight.
29. The cellulose fibers of claim 16, wherein the additive is one
or more carbohydrates or polyols.
30. The cellulose fibers of claim 16, wherein the additive is at
least one of glucose, sucrose, glycerol, and sorbitol.
31. A food composition comprising the cellulose fibers of claim 16,
wherein said food composition is chosen from the group consisting
of luxury drinks, milk component-containing drinks,
nutrition-enriched drinks, dairy products, iced products, processed
fat food products, soups, stews, seasonings, paste condiments,
fillings, gels, paste-like food products, food products containing
cereals as the main component, cakes, kneaded marine products,
live-stock products, daily dishes, foods of delicate flavor, liquid
diets, supplements and pet foods.
32. An emulsified product comprising the cellulose fibers of claim
16 and one or more proteins.
33. The emulsified product of claim 32, wherein the emulsified
product comprises one or more proteins in about 0.1 wt. % to about
10.0 wt. % of the emulsified product.
34. A composition comprising the cellulose fibers of claim 16 and
one or more surfactants.
Description
FIELD OF INVENTION
[0001] The invention relates to citrus fibers and citrus fibers
based composition in dry form and in particular to such fibers and
compositions which are readily dispersible. The invention further
relates to a method for manufacturing said fibers and compositions
and their uses.
BACKGROUND
[0002] Citrus fibers are known to have many interesting properties
making them suitable for use in a variety of products for human and
animal consumption. Citrus fibers have been successfully employed,
mainly as texturizing additives, in food and feed products and
beverages, but also in personal care, pharmaceutical and detergent
products. The use of citrus fibers in dry form (hereinafter "dry
citrus fibers") in the manufacturing of the above products is
advantageous due to the fibers' longer shelf life and reduced costs
of shipping from a fiber production plant or storage site to a
processing facility.
[0003] Dry citrus fibers and compositions containing thereof are
for example known from WO 2006/033697, WO 2012/016190, and WO
2013/109721. When carefully dried, these known citrus fibers may
retain an optimum free surface area available for binding water
upon rehydration and dispersion, which in turn provides said fibers
with thickening capabilities, good stability, and the capacity to
create optimum textures. Using various techniques such as the one
disclosed in WO 2012/016201, the properties of the dry citrus
fibers can be further tailored to provide optimum
functionalities.
[0004] It is however difficult to prepare dry citrus fibers without
affecting their dispersibility in aqueous media. A method of
enhancing the dispersibility of dry citrus fibers in an aqueous
medium is to functionalize or derivative the fibers, i.e. grafting
various chemical moieties on the surface of the fibers. U.S. Pat.
No. 5,964,983 discloses dry fibres, e.g. citrus fibers,
functionalized with acidic polysaccharides retained on their
surface. These fibers however, can only be dispersed in water with
a high-shear mixing device of the ULTRA TURRAX type and cannot be
thus considered readily dispersible.
[0005] Another method known to provide dry, dispersible fibers,
involves drying the fibers in the presence of additives. U.S. Pat.
Nos. 6,485,767 and 6,306,207 disclose dry compositions containing
up to 20 wt % of a polyhydroxylated compound and dry fibers.
Although citrus fibers were mentioned as being a suitable example,
no experimental data using such fibers was reported therein.
According to the experimental part of these publications, somewhat
dry fibers (i.e., fibers having a dry substance content of about 77
wt % and about 23 wt % moisture) extracted from sugar beet pulp
were readily dispersible in water using only vigorous stirring (500
rpm). However, the properties of these fibers can be further
optimized, in particular their moisture content and or viscoelastic
properties.
[0006] It was also observed that known dry compositions containing
citrus fibers and additives may have undesirable characteristics
such as stickiness, which in turn may cause problems during a
subsequent processing thereof. Also, the rheological behavior and
viscoelastic stability of such compositions are less than optimum
with large variations in G' being observed when changing the nature
and/or varying the amounts of the compositions' constituents.
[0007] Accordingly, there is an unmet need in the industry for
citrus fibers in dry form used as such or in compositions, which
can be readily dispersed in an aqueous medium, and which upon
dispersion provide said medium with an optimum rheological
behavior. More in particular, there is a need for dry citrus fibers
used as such or in compositions, which when dispersed in an aqueous
medium, provide the aqueous medium with optimum G' values and/or an
optimum viscoelastic stability.
SUMMARY OF INVENTION
[0008] A primary object of this invention may thus be to provide
dry citrus fibers that can be readily dispersed under low-shear
stirring in an aqueous medium to form a dispersion having optimum
rheological properties.
[0009] The foregoing and other objects of this invention are met by
providing citrus fibers in dry form having a storage modulus (G')
of at least 50 Pa, said G' being measured on an aqueous medium
containing an amount of 2 wt % citrus fibers dispersed therein
under a low-shear stirring of less than 10000 rpm.
BRIEF DESCRIPTION OF FIGURES
[0010] FIGS. 1 and 2 show NMR T.sub.2 distribution curves
characteristic to the fibers of the invention upon their dispersal
under specific conditions as detailed herein.
DETAILED DESCRIPTION
[0011] Any feature of a particular embodiment of the present
invention may be utilized in any other embodiment of the invention.
The word "comprising" is intended to mean "including" but not
necessarily "consisting of" or "composed of". In other words, the
listed steps or options need not be exhaustive. It is noted that
the examples given in the description below are intended to clarify
the invention and are not intended to limit the invention to those
examples per se. Similarly, all percentages are weight/weight
percentages unless otherwise indicated. Except in the examples and
comparative experiments, or where otherwise explicitly indicated,
all numbers in this description indicating amounts of material or
conditions of reaction, physical properties of materials and/or use
are to be understood as modified by the word "about". Unless
specified otherwise, numerical ranges expressed in the format "from
x to y" are understood to include x and y. When for a specific
feature multiple preferred ranges are described in the format "from
x to y", it is understood that all ranges combining the different
endpoints are also contemplated. For the purpose of the invention
ambient (or room) temperature is defined as a temperature of about
20 degrees Celsius.
[0012] In a first aspect, the present invention provides citrus
fibers in dry form having a storage modulus (G') of at least 50 Pa,
said G' being measured on an aqueous medium containing an amount of
2 wt % citrus fibers dispersed therein under a low-shear stirring
of less than 10000 rpm.
[0013] The storage modulus G' is commonly used in the food industry
to analyze the rheological properties of dispersions and in
particular fiber-based dispersions. In the art, by fiber-based
dispersion is understood fibers or compositions containing thereof
dispersed in an aqueous medium. G' is a measure of a deformation
energy stored in the dispersion during the application of shear
forces and provides an excellent indication of the dispersion's
viscoelastic behavior. Here, G' is measured on an aqueous medium
containing an amount of 2 wt % of citrus fibers, i.e. relative to
the total weight of the aqueous medium. It is highly desirable to
achieve dispersions having G' values as high as possible at
concentrations of fibers as low as possible when the fibers are
dispersed under low-shear in the aqueous medium.
[0014] The present inventors noticed that the citrus fibers of the
invention were able to meet the above requirements and hence, these
novel fibers may impart food, feed, pharma or personal care
formulations containing thereof with optimum rheological
properties. The novel citrus fibers have also an improved
dispersibility in that they are readily dispersible in the aqueous
medium. Moreover, since said citrus fibers may be used at lower
concentrations to achieve increased G' values, food, feed and other
manufacturers may have increased design freedom for their
respective formulations, in that they may be able to add or remove
constituents while maintaining optimum viscoelastic properties
thereof.
[0015] As used herein, "dispersibility" means that upon dispersion
in an aqueous medium, e.g. water, the dry fibers have the capacity
to largely regain their initial functionality, wherein by initial
functionality is herein understood the functionality of the fibers
before being dehydrated and/or dried. Properties defining the
initial functionality may include the fibers' swelling capacity,
viscoelasticity, water-binding capacity and stabilization
power.
[0016] The term "readily dispersible" as used herein means that it
is not necessary to use high-shear means, e.g. high-shear mixers or
homogenizers, to disperse the fibers in an aqueous medium such as
water in order to obtain a useful viscosity; but rather that the
dispersion of the fibers can be accomplished with low-shear
stirring equipment, such as for example, magnetic stirrers or
mechanical stirrers, e.g. an IKA.RTM. Eurostar mechanical stirrer
equipped with an R1342 4-bladed propeller stirrer or a Silverson
L4RT overhead batch mixer equipped with an Emulsor Screen (e.g.
with round holes of about 1 mm diameter). The term "aqueous medium"
as used herein means a liquid medium which contains water, suitable
non-limiting example thereof including pure water, a water solution
and a water suspension.
[0017] The G' of the citrus fibers of the invention is at least 50
Pa. Preferably, said G' is at least 75 Pa, more preferably at least
100 Pa, even more preferably at least 125 Pa, yet even more
preferably at least 150 Pa, most preferably at least 170 Pa.
[0018] The inventors surprisingly observed that the citrus fibers
of the invention manifest the high G' values upon being dispersed
in an aqueous medium under low shear, i.e. stirring with less than
10000 rpm. This is even more surprising since said high G' values
were achieved at the low fiber concentrations, e.g. of 2 wt %. The
aqueous medium preferably contains water in an amount of at least
75 wt %, more preferably at least 85 wt %, most preferably at least
95 wt %, relative to the total amount of the medium. Preferably,
the stirring used to achieve the dispersion of the fibers of the
invention in the aqueous medium is at most 8000 rpm, more
preferably at most 5000 rpm, most preferably at most 3000 rpm.
[0019] The citrus fibers of the invention are in dry form, which is
herein understood as containing an amount of liquid, e.g. water
and/or organic solvent, of less than 20 wt % relative to the total
weight of the fibers. Preferably said fibers contain an amount of
water (i.e. moisture content) of at most 12 wt %, more preferably
at most 10 wt %, or most preferably at most 8 wt %. Such dry fibers
may be more economical to transport and store while being readily
dispersible in the aqueous medium.
[0020] The fibers of the invention are citrus fibers. The term
"fiber" as used herein, refers to an elongated object comprising
microfibrils of cellulose, the fiber having a length (major axis)
and a width (minor axis) and having length to width ratio of at
least 5, more preferably at least 10, or most preferably at least
15, as observed and measured by a high-resolution scanning electron
microscope ("SEM"). The length of the citrus fibers is preferably
at least 0.5 .mu.m, more preferably at least 1 .mu.m. The width of
the citrus fibers is preferably at most 100 nm, more preferably at
most 50 nm, most preferably at most 15 nm.
[0021] Citrus fibers are fibers contained by and obtained from the
fruits of the citrus family. The citrus family is a large and
diverse family of flowering plants. The citrus fruit is considered
to be a specialized type of berry, characterized by a leathery peel
and a fleshy interior containing multiple sections filled with
juice filled sacs. Common varieties of the citrus fruit include
oranges, sweet oranges, clementines, kumquats, tangerines,
tangelos, satsumas, mandarins, grapefruits, citrons, pomelos,
lemons, rough lemons, limes and leech limes. The citrus fruit may
be early-season, mid-season or late-season citrus fruit. Citrus
fruits also contain pectin, common in fruits, but found in
particularly high concentrations in the citrus fruits. Pectin is a
gel-forming polysaccharide with a complex structure. It is
essentially made of partly methoxylated galacturonic acid, rhamnose
with side chains containing arabinose and galactose, which are
linked through a glycosidic linkage. The pectin content of the
citrus fruit may vary based on season, where ripe fruit may contain
less pectin than unripe fruit.
[0022] Citrus fiber is to be distinguished from citrus pulp, which
are whole juice sacs and are sometimes referred to as citrus
vesicles, coarse pulp, floaters, citrus cells, floating pulp, juice
sacs, or pulp. Citrus fiber is also to be distinguished from citrus
rag, which is a material containing segment membrane and core of
the citrus fruit.
[0023] The citrus fibers are typically obtained from a source of
citrus fibers, e.g. citrus peel, citrus pulp, citrus rag or
combinations thereof. Moreover, the citrus fibers may contain the
components of the primary cell walls of the citrus fruit such as
cellulose, pectin and hemicelluloses and may also contain
proteins.
[0024] Preferably, the citrus fibers of the invention did not
undergo any substantial chemical modification, i.e. said fibers
were not subjected to chemical modification processes such as
esterification, derivatisation or enzymatic modification and
combinations thereof.
[0025] Preferably, the citrus fibers in accordance with the
invention have a crystallinity of at least 10%, more preferably at
least 20%, most preferably at least 30% as measured on a dried
(less than 20 wt % water content relative to the content of fibers)
sample by X-ray diffraction method (Siegel method). Preferably, the
crystallinity of said fibers is between 10% and 60%.
[0026] The inventors surprisingly found that suitably prepared
citrus fibers in dry form can be readily dispersed in an aqueous
medium by applying relatively low levels of shear compared to
conventional dry citrus fibers. Without wishing to be bound by
theory, it is believed thru the excellent dispersion properties of
the citrus fibres are related to the structure that is imparted on
them in the dry form. It was further surprisingly found by the
present inventors that this structure can suitably be characterized
by a standardized shear storage modulus (G*) that is determined for
a standardized dispersion of such citrus fibers.
[0027] Consequently, according to a second aspect, the present
invention provides citrus fibers, in dry form having a G* of at
least 50 Pa, wherein G* is measured by: [0028] a. providing the
fibers in a particulate form wherein the particles can pass a 500
.mu.m sieve by milling the citrus fiber material using a Waring
8010EG laboratory blender equipped with an SS110 Pulverizer
Stainless Steel Container using its low speed setting (18000 rpm)
for 4 plus or minus 1 seconds; sieving the milled material using an
AS200 digital shaker from Retsch GmbH Germany with a sieve set of
10 mm, 500 .mu.m, 250 .mu.m and 50 .mu.m sieves, whilst shaking for
1 minute at an amplitude setting of 60; remilling and resieving the
particles larger than 500 .mu.m until they passed the 500 .mu.m
sieve and combining the sieved fractions; [0029] b. dispersing an
amount of the fibers in particulate form so as to obtain 300 grams
of an aqueous dispersion comprising 2 wt % of dry citrus fiber by
weight of the dispersion, wherein the dispersion is buffered at pH
7.0, and whereby the fibers are dispersed using a Silverson
overhead mixer equipped with an Emulsor screen having round holes
of 1 mm diameter at 3000 rpm for 120 seconds; and [0030] c.
determining G* of the resultant dispersion using a parallel plate
rheometer.
[0031] Step a. of the above protocol for the determination of G*
serves to facilitate efficient dispersion during step b. The citrus
fiber in dry form may come at a variety of particle sizes.
Therefore, step a. includes milling of the citrus fiber so as to
obtain the fibers in the specified particulate form. Suitable
milling is provided by dry milling using a laboratory-scale Waring
blender. The buffered dispersion of step b. may be prepared using
any suitable buffer system. Preferably, a phosphate-based buffer is
used. In step c, the Silverson overhead mixer preferably is an L4RT
overhead mixer. G* is measured using any suitable parallel plate
rheometer, for example an ARG2 rheometer of TA Instruments. G* is
preferably measured at a strain level of 0.1%. A preferred way of
establishing the G* is by following the protocol in the way
described below. The above protocol and the Examples provide
methods of measuring the G*. However, the G* may also be determined
by a different protocol, as long as that protocol would lead to the
same physical result, i.e. it would yield the same G* for a
particular dry citrus fiber preparation as the above protocol.
[0032] The citrus fibers in dry form according to the second aspect
of the invention preferably have a G* of at least 100 Pa, more
preferably at least 150 Pa, even more preferably at least 200 Pa,
still more preferably at least 250 Pa, and yet more preferably at
least 300 Pa and even more preferably at least 350 Pa. The citrus
fibers in dry form preferably have a G* of up to 10000 Pa, and more
preferably of up to 1000 Pa. Thus it is particularly preferred that
the citrus fibers in dry form have a G* of between 50 Pa and 10000
Pa, more preferably between 300 Pa and 1000 Pa.
[0033] In a third aspect, the present invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having a
storage modulus (G') of at least 100 Pa, said G' being measured on
an aqueous medium obtained by dispersing therein an amount of said
composition under a low shear stirring of less than 10000 rpm to
obtain a citrus fibers' concentration of 2 wt % relative to the
total weight of the aqueous medium. Preferably. G' is at least 150
Pa, more preferably at least 170 Pa, even more preferably at least
190 Pa, yet even more preferably at least 250 Pa, yet even more
preferably at least 300 Pa, most preferably at least 350 Pa when
said composition is dispersed under a low shear stirring of less
than 5000 rpm, more preferably less than 3000 rpm. Preferably. G'
is at least 375 Pa, more preferably at least 425 Pa, even more
preferably at least 475 Pa, yet even more preferably at least 550
Pa, yet even more preferably at least 600 Pa, most preferably at
least 650 Pa when said composition is dispersed under a low shear
stirring of between 6000 and 10000 rpm, more preferably between
7500 and 8500 rpm.
[0034] The composition of the invention, hereinafter the inventive
composition, is in dry form, which is herein understood that the
composition contains an amount of liquid, e.g. water and/or organic
solvent, of less than 20 wt % relative to the total weight of said
composition. Preferably the composition contains an amount of water
of at most 12 wt %, more preferably at most 10 wt %, or most
preferably at most 8 wt %. Such a dry composition may be more
economical to transport and store.
[0035] The inventive composition comprises an additive distributed
between the citrus fibers. By the term "additive distributed
between the citrus fibers" is herein understood that said additive
is distributed inside a volume defined by the totality of fibers
and preferably also between the microfibrils forming the fibers.
Preferably, the citrus fibers used in the inventive composition are
the citrus fibers of the invention.
[0036] Preferably, the inventive composition contains the additive
in an amount of at least 5 wt % relative to the weight of the
anhydrous citrus fibers contained by said composition, more
preferably of at least 10 wt %, even more preferably of at least 20
wt %, or most preferably of at least 30 wt %. The weight of the
anhydrous fibers in the composition is the weight of the fibers
obtained by drying 10 grams of the composition without the additive
at 105.degree. C. under normal atmosphere until constant weight is
obtained. The same determination can be carried out in the presence
of the additive; however, in this case the amount of additive in
the sample has to be subtracted therefrom. The upper limit for the
additive amount in the inventive composition can be kept within
large variances since it was observed that the citrus fibers
contained by said composition may have the ability to optimally
include said additive. A preferred upper limit for the additive
amount is at most 1000 wt % relative to the weight of the fibers in
said composition, more preferably at most 750 wt %, or most
preferably at most 500 wt %.
[0037] Preferably, the inventive composition has an additive:fiber
(A:F) ratio of between 0.01:1.0 and 10.0:1.0 by weight, more
preferably between 0.1:1.0 and 9.0:1.0 by weight, most preferably
between 0.4:1.0 and 8.0:1.0 by weight. In a first embodiment, the
A:F ratio is between 0.01:1.0 and 3.8:1.0, more preferably between
0.05:1.0 and 3.4:1.0, most preferably between 0.10:1.0 and 3.0:1.0.
In a second embodiment, the A:F ratio is between 4.0:1.0 and
10.0:1.0, more preferably between 4.5:1.0 and 9.0:1.0, most
preferably between 5.0:1.0 and 8.0:1.0. The inventors observed that
the inventive composition has stable rheological properties in that
when varying the A:F ratio of the composition, the G' varies with a
standard deviation (STDEV) of at most 50% of a maximum (MAX),
wherein MAX is the maximum measured value of the G'.
[0038] For compositions comprising additives and fibers, G' may
depend on the amount and nature of the fibers but also on the A:F
ratio. In other words, a composition with a specific A:F ratio has
a specific G' and by changing said ratio, G' changes also. The
amount with which G' changes with the A:F ratio, e.g. as expressed
in terms of the standard deviation (STDEV), may give an indication
of the dispersibility and the rheological (or viscoelastic)
stability of the composition.
[0039] The inventors observed that while changing the A:F ratio of
the inventive composition, G' may experience a maximum (MAX); and
that the deviation expressed as STDEV of G' from MAX for various
A:F ratios, may also give an indication on the dispersibility and
the rheological stability of the composition. They observed that an
increased deviation of STDEV front MAX may deleteriously influence
the processability of the composition as processing steps with
starkly different sets of parameters may be required for each A:F
ratio in order to achieve an optimal processing thereof. The
inventors also observed that various characteristics of the
composition such as shelf stability and sensory perception,
including texture and mouthfeel may also be negatively influenced
by an increased deviation of STDEV from MAX.
[0040] The inventors observed that in the known compositions,
additives were not efficiently mixed with said fibers, which may
result in a less optimal distribution of the additive between the
fibers. This may be reflected by the compositions' less optimal
rheological behaviour, e.g. large variations of the compositions'
G' with the A:F ratio and in particular large deviations of STDEV
from MAX.
[0041] For the composition of the invention the STDEV
characteristic to the G' variations is at most 50% of the MAX.
Preferably, the STDEV is at most 40% of said MAX, more preferably
at most 30% of said MAX, even more preferably at most 20% of said
MAX, most preferably at most 16% of said MAX. The inventive
composition may also be considered readily dispersible. Moreover,
the inventors observed that when the A:F ratio is varied, the
obtained G' values are closely grouped around the MAX; hence the
inventive composition may have a viscoelastic behavior which is
less dependent on the concentration and/or nature of added
constituents than known citrus fiber-based compositions and may
thus offer increased design freedom for products whose rheological
or other properties are modified with the help of these citrus
fibers.
[0042] The additive used in the inventive composition, is
preferably chosen from carbohydrates and polyols. Carbohydrates
include also derivatives thereof. Preferred carbohydrates are
linear or cyclic monosaccharides, oligosaccharides, polysaccharides
and fatty derivatives thereof. Examples of fatty derivatives may
include sucroesters or fatty acid sucroesters, carbohydrate
alcohols and mixtures thereof. Non-limiting examples of
monosaccharides include fructose, mannose, galactose, glucose,
talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose
and ribose. Non-limiting examples of oligosaccharides include
sucrose, maltose and lactose. Non-limiting examples of
polysaccharides include nonionic polysaccharides, e.g.
galactomannans, such as guar gum, carob gum, starch and its
nonionic derivatives, and nonionic cellulose derivatives; but also
anionic polysaccharides such as xanthan gum, succinoglycans,
carrageenans and alginates. Preferred examples of polyols include
without limitation glycerol, pentaerythritol, propylene glycol,
ethylene glycol and/or polyvinyl alcohols. The additives enumerated
above can be used alone or in mixtures or blends of two or more
additives.
[0043] In a preferred embodiment, the additive is a hydrophilic
additive, suitable examples including dextrins; water-soluble
sugars such as glucose, fructose, sucrose, lactose, isomerized
sugar, xylose, trehalose, coupling sugar, paratinose, sorbose,
reduced starch-saccharified gluten, maltose, lactulose,
fructo-oligosaccharide, galacto-oligosaccharide; hydrophilic
starches and sugar alcohols such as xylitol, maltitol, mannitol and
sorbitol but also combinations thereof.
[0044] In another preferred embodiment, the additive is a starch.
The starch used in this invention may be any starch derived from
any native source. A native starch as used herein, is one as it is
found in nature. Also suitable are starches derived from a plant
obtained by any known breeding techniques. Typical sources for the
starches are cereals, tubers and roots, legumes and fruits. The
native source can be any variety, including without limitation,
corn, potato, sweet potato, barley, wheat, rice, sago, amaranth,
tapioca (cassava), arrowroot, canna, pea, banana, oat, rye,
triticale, and sorghum, as well as low amylose (waxy) and high
amylose varieties thereof. Low amylose or waxy varieties is
intended to mean a starch containing at most 10% amylose by weight,
preferably at most 5%, more preferably at most 2% and most
preferably at most 1% amylose by weight of the starch. High amylose
varieties is intended to mean a starch which contains at least 30%
amylose, preferably at least 50% amylose, more preferably at least
70% amylose, even more preferably at least 80% amylose, and most
preferably at least 90% amylose, all by weight of the starch. The
starch may be physically treated by any method known in the art to
mechanically alter the starch, such as by shearing or by changing
the granular or crystalline nature of the starch, and as used
herein is intended to include conversion and pregelatinization.
Methods of physical treatment known in the art include
ball-milling, homogenization, high shear blending, high shear
cooking such as jet cooking or in a homogenizer, drum drying,
spray-drying, spray cooking, chilsonation, roll-milling and
extrusion, and thermal treatments of low (e.g. at most 2 wt %) and
high (above 2 wt %) moisture containing starch. The starch may be
also chemically modified by treatment with any reagent or
combination of reagents known in the art. Chemical modifications
are intended to include crosslinking, acetylation, organic
esterification, organic etherification, hydroxyalkylation
(including hydroxypropylation and hydroxyethylation),
phosphorylation, inorganic esterification, ionic (cationic,
anionic, nonionic, and zwitterionic) modification, succination and
substituted succination of polysaccharides. Also included are
oxidation and bleaching. Such modifications are known in the art,
for example in Modified starches: Properties and Uses Ed. Wurzburg,
CRC Press, Inc., Florida (1986).
[0045] In another preferred embodiment, the additive is a blend
containing a first additive and a second additive, the first
additive being a starch and the second additive being a
carbohydrate, a derivatives thereof or a polyol, wherein the second
additive is different than the first additive. Preferably, the
starch is chosen from the group of starches containing a native
starch, a thermally treated starch, a chemically modified starch
and combinations thereof. Preferably, the second additive is chosen
from the group consisting of glucose, sucrose, glycerol and
sorbitol.
[0046] Most preferred additives for use in the inventive
composition are glucose, sucrose, glycerol and sorbitol.
[0047] The inventors surprisingly found that a suitably prepared
composition of matter in dry form, comprising citrus fibers and an
additive distributed between said fibers can be readily dispersed
in an aqueous medium by applying relatively low levels of shear
compared to conventional dry citrus fibers. It was further
surprisingly found by the present inventors that this structure can
suitably be characterised by a standardized modulus (G*) that is
determined for a standardized dispersion of the composition of
matter. Consequently, according to a fourth aspect, the present
invention provides a composition of matter in dry form comprising
citrus fibers and an additive distributed between said fibers, said
composition having a G* of at least 150 Pa, wherein G* is measured
by [0048] a. providing the composition in a particulate form
wherein the particles can pass a 500 .mu.m sieve by milling the
citrus fiber material using a Waring 8010EG laboratory blender
equipped with an SS110 Pulverizer Stainless Steel Container using
its low speed setting (18000 rpm) for 4 plus or minus 1 seconds;
sieving the milled material using an AS200 digital shaker from
Retsch GmbH Germany with a sieve set of 10 mm, 500 .mu.m, 250 .mu.m
and 50 .mu.m sieves, whilst shaking for 1 minute at an amplitude
setting of 60; remilling and retrieving the particles larger then
500 .mu.m until they passed the 500 .mu.m sieve and combining the
sieved fractions; [0049] b. dispersing an amount of the composition
in particulate form so as to obtain 300 grams of an aqueous
dispersion comprising 2 wt % of dry citrus fiber by weight of the
dispersion, wherein the dispersion is buffered at pH 7.0, and
whereby the fibers are dispersed using a Silverson overhead mixer
equipped with an Emulsor screen having round holes of 1 mm diameter
at 3000 rpm for 120 seconds; and [0050] c. determining G* of the
resultant dispersion using a parallel plate rheometer.
[0051] Step a. of the above protocol for the determination of G*
serves to facilitate efficient dispersion during step b. The
composition of matter in dry form may come at a variety of particle
sizes. Therefore, step a. includes milling of the composition so as
to obtain the fibers in the specified particulate form. Suitable
milling is provided by dry milling using a laboratory-scale Waring
blender. The buffered dispersion of step b. may be prepared using
any suitable butter system. Preferably, a phosphate-based buffer is
used. In step c, the Silverson overhead mixer preferably is an L4RT
overhead mixer. G* is measured using any suitable parallel plate
rheometer, for example an ARG2 rheometer of TA Instruments. G* is
preferably measured at a strain level of 0.1%. A preferred way of
establishing the G* is by following the protocol in the way
described below. The above protocol and the Examples provide
methods of measuring the G*. However, the G* may also be determined
by a different protocol, as long as that protocol would lead to the
same physical result, i.e. it would yield the same G* for a
particular dry citrus fiber preparation as the above protocol.
[0052] The composition of matter in dry form according to the
fourth aspect of the invention preferably has a G* of at least 200
Pa, more preferably at least 250 Pa, even more preferably at least
300 Pa and still more preferably at least 350 Pa. The composition
of matter in dry form preferably has a G* of up to 10000 Pa, and
more preferably of up to 1000 Pa. Thus it is particularly preferred
that the composition of matter in dry form has a G* of between 150
Pa and 10000 Pa, more preferably between 300 Pa and 1000 Pa.
[0053] The preferences and examples regarding the citrus fiber, the
type and amount of additive in the composition of matter according
to this fourth aspect of the invention are as presented hereinabove
for the composition of matter in dry form comprising citrus fibers
and an additive distributed between said fibers according to the
present invention. It is particularly preferred that the additive
is sucrose and that the ratio A:F of additive to citrus fiber is
0.10 to 1.0 and 3.0 to 1.0 by weight.
[0054] In a fifth aspect, the present invention provides cellulose
fibers in dry form having a transverse relaxation factor
("R.sub.2*") as measured by nuclear magnetic resonance ("NMR") of
at least 0.65. The preferred cellulose fibers are citrus fibers.
Preferably, the R.sub.2* of said dry cellulose fibers is at least
0.70, more preferably at least 0.80, even more preferably at least
0.90, yet even more preferably at least 1.10, and most preferably
at least 1.20. Preferably, the moisture content of the dry
cellulose fibers is at most 20 wt % relative to the total mass of
fibers, more preferably at most 12 wt %, even more preferably at
most 10 wt %, most preferably at most 8 wt %. To inventors'
knowledge, cellulose fibers and in particular citrus fibers dried
to a moisture content below the above mentioned amounts and having
the R.sub.2* in accordance with the invention were never
manufactured hitherto.
[0055] The inventors surprisingly observed that R.sub.2* may be
used to characterize and describe dry cellulose fibers and in
particular dry citrus fibers. Without being bound to any theory, it
is believed that R.sub.2* may provide an indication of the
magnitude of the available surface area of the fibers. A higher
R.sub.2* value thus signifies a larger available surface area of a
fiber, which in turn may indicate an increased texturizing capacity
of the fibers, i.e. the ability of the fibers to form and/or
stabilize textures. It was observed that R.sub.2* values, such as
those characteristic for the fibers of the invention, were never
achieved hitherto, as the publicly reported values and the measured
values of any commercial products existent so far are well below
0.65. It is thus believed that the known dry cellulose fibers and
in particular the known dry citrus fibers have a less than optimum
texturizing capacity.
[0056] The inventors surprisingly found that suitably prepared
citrus fibers in dry form can be readily dispersed in an aqueous
medium by applying relatively low levels of shear compared to
conventional dry citrus fibers. Likewise, it was surprisingly found
that redispersion of a suitably prepared composition of matter in
dry form comprising citrus fibers and an additive distributed
between said fibers can be dispersed even more readily. Without
wishing to be bound by theory, it is believed that the excellent
dispersion properties of said citrus fibers or said composition in
dry form are related to the structure that is imparted on them in
the dry form. It was further surprisingly found by the present
inventors that this structure can suitably be characterized by a
Fiber Availability Parameter (FAP). This finding applies to both
the citrus fibers in dry form and to the composition of matter in
dry form. The FAP is measured using a technique based on NMR.
Therefore, according to a sixth aspect, the invention provides
citrus fibers in dry form having a FAP of at least 0.35 Hz.
Similarly, according to a seventh aspect, the invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers having a FAP of at least
0.70 Hz.
[0057] The FAP is determined in essentially the same way for both
the citrus fibers according to the sixth aspect and the composition
of matter in dry form according to the seventh aspect of the
invention. Therefore, the term "citrus fiber material" is herein
understood to refer to either the citrus fibers in dry form
according to the sixth aspect or the composition of matter in dry
form comprising citrus fibers and an additive distributed between
said fibers according to the seventh aspect of the invention, as
the case may be. The FAP provides a measure for the internal
configuration of the citrus fiber material and the extent to which
the fibers are available for redispersion at low shear levels as a
result of that configuration. The FAP is based on the NMR method
performed on a standardized sample comprising the citrus fiber
material in dispersed form. The FAP of the citrus fiber material is
established by the following protocol. The protocol to establish
FAP includes three parts: sample preparation, NMR measurement to
collect Carr-Purcell-Meiboom-Gill (CPMG) relaxation decay data, and
data analysis to calculate the FAP value. Thus, the protocol
includes the sample preparation steps of: [0058] a. providing the
citrus fiber material in a particulate form wherein the particles
can pass a 500 .mu.m sieve, by milling the citrus fibre material
using a Waring 8010EG laboratory blender equipped with an SS110
Pulverizer Stainless Steel Container using its low speed setting
(18000 rpm) for 4 plus or minus 1 seconds; sieving the milled
material using an AS200 digital shaker from Retsch GmbH Germany
with a sieve set of 10 mm, 500 .mu.m, 250 .mu.m and 50 .mu.m
sieves, whilst shaking for 1 minute at an amplitude setting of 60;
remilling and resieving the particles larger than 500 .mu.m until
they passed the 500 .mu.m sieve and combining the sieved fractions;
[0059] b. using the citrus fiber material to prepare 300 grams of a
concentration-standardized sample in the form of a dispersion at
room temperature, wherein the concentration-standardized sample
comprises the fibers contained in the citrus fiber material at a
concentration of 0.50 wt-% with respect to the weight of the
standardized sample; by first combining the citrus fiber material
with water to gain a total weight of 250 grams, optionally adding a
preservative, adjusting the concentration of the sample to a pH of
3.6.+-.0.1 using aqueous hydrochloric acid and adjusting the volume
of the resulting mixture to a total of 300 grams by adding water;
[0060] c. evenly distributing the fibers inside the
concentration-standardized sample volume by agitating the sample
using a Silverson overhead mixer equipped with an Emulsor screen
having round holes of 1 mm diameter at 1500 rpm for 120 seconds;
[0061] d. adjusting the pH of the concentration-standardized sample
to 3.3.+-.0.1; [0062] e. transferring an aliquot of the
concentration- and pH-standardized sample to a flat-bottom NMR tube
of 10 mm diameter, ensuring a fill height such that upon placement
of the sample in the NMR spectrometer of step h. the fill height is
within the region where the Rf field of the coil of the NMR
spectrometer is homogeneous.
[0063] Step a. of the above protocol for the determination of the
FAP serves to facilitate efficient dispersion during step b. The
citrus fiber material may come at a variety of suitable particle
sizes. Therefore, step a. includes milling of the citrus fiber
material so as to obtain the material in the specified particulate
form. Suitable milling is provided by dry milling using a
laboratory-scale Waring blender. The sample is preferably kept or
made free from larger particulate material, including for instance
fragments of whole or multiple cells and other non-homogenized
material. The distributing step c is intended to provide an even
distribution of the fibers over the sample volume, whilst having a
controlled effect on the availability of the fibers for dispersion.
In step d. the pH is suitably standardized with the aid of
hydrochloric acid. The optimal fill height in step e may depend on
the type of NMR spectrometer used, as known by the skilled person.
If will typically be about 1 cm. In the further steps of the
protocol, the concentration- and pH-standardized sample will be
referred to as the standardized sample.
[0064] The data analysis requires comparison of a T.sub.2
distribution curve (see below) of the standardized sample with a
matrix reference sample, which should preferably be essentially
free from cellulose fibers. Therefore, the protocol also includes
the step of: [0065] f. preparing a matrix reference sample by
centrifuging an aliquot of the standardized sample in a 2 ml
Eppendorf cup at a relative centrifugation force of 15000 for 10
minutes and transferring the supernatant to a flat-bottom NMR tube
of 10 mm diameter, ensuring a fill height such that upon placement
of the sample in the NMR spectrometer of step h, the fill height is
within the region where the RF field of the coil of the NMR
spectrometer is homogeneous. Subsequently, to collect and analyze
the data, the protocol includes the steps of: [0066] g.
equilibrating the NMR tubes at a temperature of 20.degree. C.;
[0067] h. recording relaxation decay data for the standardized
sample at 20.degree. C. on an NMR spectrometer operating at a
proton resonance frequency of 20 MHz, using a CPMG T.sub.2
relaxation pulse sequence, with a 180.degree. pulse spacing of 200
microseconds, and a recycle delay time of 30 seconds; [0068] i.
recording relaxation decay data for the matrix reference sample
under the same conditions as in step h; [0069] j. performing
inverse Laplace transformation to the obtained decay data for both
the standardized sample and the matrix reference sample, requiring
T.sub.2 to be in the range of 0.01 to 10 seconds; [0070] k.
identifying in the T.sub.2 distribution curve of the standardized
sample the peak corresponding to the water protons of which the
T.sub.2 is averaged by exchange between the bulk water phase and
the surface of the defibrillated primary cell wall material and
identifying in the T.sub.2 distribution curve of the matrix
reference sample the peak corresponding to the bulk water phase;
[0071] l. calculating T.sub.2 (sample), which is defined as the
weighted average T.sub.2 value for the identified peak in the
T.sub.2 distribution curve of the standardized sample and similarly
calculating T.sub.2 (matrix) which is defined as the weighted
average T.sub.2 value for the identified peak in the T.sub.2
distribution curve of the matrix reference sample; [0072] m.
calculating the values of R.sub.2(sample) and R.sub.2(matrix),
where:
[0072] R.sub.2(sample)=1/T.sub.2(sample), and
R.sub.2(matrix)=1/T.sub.2(matrix); [0073] n. calculating the FAP of
the fiber mass as
[0073] FAP=R.sub.2(sample)-R.sub.2(matrix),
[0074] The CPMG T.sub.2 relaxation pulse sequence is well-known in
the field of NMR spectroscopy (See Effects of diffusion on free
precession in nuclear magnetic resonance experiments, Carr, H. Y.,
Purcell, E. M., Physical Review, Volume 94, Issue 3, 1954, Pages
630-638/Modified spin-echo method for measuring nuclear relaxation
times, Meiboom, S., Gill, D., Review of Scientific Instruments,
Volume 29, Issue 8, 1958, Pages 688-691). Suitable time domain NMR
spectrometers to perform this type of spectroscopy are well-known.
Similarly, the usual measures to ensure the recording of reliable
data are well-known in the field of time domain NMR spectroscopy.
For example, the electromagnetic field should be sufficiently
homogeneous at the locus where the sample volumes are placed. The
field homogeneity can for example be checked by verifying whether a
reference sample of pure water, yields a T.sub.2* (T-two-star) for
water protons of more than 2 milliseconds. The inverse Laplace
transformation of step j may suitably be carried out using a
non-negative least square constraints algorithm Isqnonneg (Lawson,
C. L. and R. J. Hanson, Solving Least Squares Problems,
Prentice-Hall, 1974, Chapter 23, p. 161), with the regularization
parameter lambda set to 0.2. Software packages suitable for
implementing the algorithm and carrying out the transform are
well-known, Matlab being an example of such software.
[0075] In step k the peak that is selected in the T.sub.2
distribution curve of the standardized sample, typically is the
dominant peak, if the system is sufficiently homogeneous. In
general, the peak that should be selected in the T.sub.2
distribution curve is that corresponding to water protons of which
the T.sub.2 is averaged by diffusion and chemical exchange between
bulk and surface sites of the dispersed citrus fiber material. This
peak is particularly well-defined if the citrus fibre material is
evenly distributed over the standardized sample. In most typical
cases, there will be only one such peak, as can be seen in the
examples in the Examples section below.
[0076] The weighted average T.sub.2 in step 1 is for example
suitably calculated by the summation
I ( T 2 ) T 2 I ( T 2 ) ##EQU00001##
[0077] Here, I(T.sub.2) is the intensity at value T.sub.2 and both
summations are over the width of the peak.
[0078] A preferred way of establishing the FAP for the citrus fiber
material is by following the protocol in the way described in the
Examples section below. The above protocol and the Examples provide
methods of measuring the FAP. However, the FAP may also be
determined by a different protocol, as long as that protocol would
lead to the same physical result, i.e. it would yield the same FAP
for a particular citrus fibre material as the above protocol.
[0079] In summary, the FAP that is determined as described here
thus provides a measure for the degree to which the fibers in the
citrus fiber material are available for redispersion.
[0080] The citrus fibres in dry form according to the sixth aspect
of the invention preferably have a FAP of at least 0.35 Hz and more
preferably of at least 0.37 Hz. The citrus fibers preferably have a
FAP of at most 5.0 Hz, more preferably at most 3.0 Hz and even more
preferably at most 2.0 Hz.
[0081] The composition of matter in dry form according to the
seventh aspect of the present invention preferably has a FAP of at
least 0.60 Hz, more preferably of at least 0.70 Hz and even more
preferably at least 0.74 Hz. The composition of matter preferably
has a FAP of at most 5.0 Hz, more preferably at most 3.0 Hz and
even more preferably at most 2.0 Hz. The preferences and examples
regarding the citrus fiber, the type and amount of additive in the
composition of matter according to this aspect of the invention are
as presented hereinabove for the composition of matter in dry form
comprising citrus fibers and an additive distributed between said
fibres according to the present invention. It is particularly
preferred that the additive is sucrose and that the ratio A:F of
additive to citrus fiber is 0.10 to 1.0 and 3.0 to 1.0 by
weight.
[0082] In an eight aspect, the present invention provides cellulose
fibers in dry form having a self-suspending capacity (SSC) of at
least 5%. The preferred cellulose fibers are citrus fibers. To
inventors' knowledge, no cellulose or citrus fibers produced
hitherto had a SSC as high as the fibers of the invention.
Preferably, the SSC of the dry cellulose fibers is at least 8%,
more preferably at least 12%, even more preferably at least 15%,
yet even more preferably at least 17%, and most preferably at least
19%. Preferably, the moisture content of the dry cellulose fibers
is at most 20 wt % relative to the total mass of fibers, more
preferably at most 12 wt %, even more preferably at most 10 wt %,
most preferably at most 8 wt %. The SSC of fibers may give an
indication on how stable may be a dispersion of said fibers in an
aqueous media. A higher SSC of fibers may thus indicate that
aqueous dispersions containing thereof have improved
stabilities.
[0083] The "self-suspending capacity" of a citrus fibre material
may be determined using the following protocol: [0084] a. providing
the citrus fibre material in a particulate form wherein the
particles can pass a 500 .mu.m sieve; by milling the citrus fibre
material using a Waring 8010EG laboratory blender equipped with an
SS110 Pulverizer Stainless Steel Container using its low speed
netting (18000 rpm) for 4 plus or minus 1 seconds; sieving the
milled material using an AS200 digital shaker from Retsch GmbH
Germany with a sieve set of 10 mm, 500 .mu.m, 250 .mu.m and 50
.mu.m sieves, whilst shaking for 1 minute at an amplitude setting
of 60; remilling and resieving the particles larger than 500 .mu.m
until they passed the 500 .mu.m sieve and combining the sieved
fractions; [0085] b. preparing a dispersion of the citrus fibre
material, comprising the fibres contained in the citrus fibre
material at a concentration of 0.1 wt-% by agitating the sample
using a Silverson overhead mixer equipped with an Emulsor screen
having round holes of 1 mm diameter at 3000 rpm for 120 seconds;
[0086] c. filling a 100 ml graded glass measuring cylinder with 100
ml of said dispersion; [0087] d. closing the cylinder and gently
turning it up and down for 10 times to ensure a proper wetting of
the citrus fiber material [0088] e. allowing the citrus fiber
material to settle for 24 hours at room temperature [0089] f.
visually determining the volume occupied by the cell fiber material
suspension [0090] g. calculating the SSC by expressing the volume
of step e. as a percentage of the total volume.
[0091] Step a. of the above protocol serves to facilitate efficient
dispersion during step b. The citrus fibre material in dry form may
come at a variety of particle sizes. Therefore, step a. includes
milling of the citrus fibre material so as to obtain the fibres in
the specified particulate form. Suitable milling is provided by dry
milling using a laboratory-scale Waring blender. In step b., the
Silverson overhead mixer preferably is an L4RT overhead mixer.
[0092] The volume occupied in step f. is suitably determined by
optical inspection. In step g., if for example the volume occupied
by the cell wall material suspension is 80 ml, this is expressed as
a self-suspending capacity SSC of 80%.
[0093] In a ninth aspect, the present invention provides cellulose
fibers in dry form having a yield stress (YS) of at least 2.0 Pa,
said YS being measured on an aqueous medium containing an amount of
2 wt % citrus fibers dispersed therein under a low-shear stirring
of less than 10000 rpm. YS is measured on an aqueous medium
containing an amount of 2 wt % of citrus fibers, i.e. relative to
the total weight of the aqueous medium. The preferred cellulose
fibers are citrus fibers. In a preferred embodiment, the fibers are
dispersed under a low shear stirring of at most 3000 rpm. In
another preferred embodiment, the fibers are dispersed under a low
shear stirring of between 7000 rpm and 10000 rpm, more preferably
about 8000 rpm and the YS of the dry cellulose fibers is at least
3.0, more preferably at least 7.0, most preferably at least 10.0.
Preferably, the moisture content of the dry cellulose fibers is at
most 20 wt % relative to the total mass of fibers, more preferably
at most 12 wt %, even more preferably at most 10 wt %, most
preferably at most 8 wt %. The YS may give an indication of the
fibers' capacity to influence the viscoelastic properties of a
dispersion containing thereof. A higher YS may indicate that a
lower amount of fibers may be needed to achieve certain
viscoelastic properties. To inventors' knowledge, no cellulose or
citrus fibers produced hitherto and processed into a dispersion
under the conditions presented hereinabove (e.g. rpm, fiber
concentration, etc.) had the ability to provide a dispersion
containing thereof with YS values as high as those provided by the
present invention.
[0094] In a tenth aspect, the present invention provides citrus
fibers in dry form, having a standardized yield stress (YS*) of at
least 2.0 Pa wherein YS* is measured by [0095] a. providing the
fibers in a particulate form wherein the particles can pass a 500
.mu.m sieve, by milling the citrus fiber material using a Waring
8010EG laboratory blender equipped with an SS110 Pulverizer
Stainless Steel Container using its low speed setting (18000 rpm)
for 4 plus or minus 1 seconds; sieving the milled material using an
AS200 digital shaker from Retsch GmbH Germany with a sieve set of
10 mm, 500 .mu.m, 250 .mu.m and 50 .mu.m sieves, whilst shaking for
1 minute at an amplitude setting of 60, remilling and resieving the
particles larger than 500 .mu.m until they passed the 500 .mu.m
sieve and combining the sieved fractions; [0096] b. dispersing an
amount of the fibers in particulate form so as to obtain 300 grams
of an aqueous dispersion comprising 2 wt % of dry citrus fiber by
weight of the dispersion, wherein the dispersion is buffered at pH
7.0, and whereby the fibers are dispersed using a Silverson
overhead mixer equipped with an Emulsor screen having round holes
of 1 mm diameter at 3000 rpm for 120 seconds; and [0097] c. using a
parallel plate rheometer determining the shear storage modulus G'
of the resultant dispersion as a function of the strain percentage
and establishing the YS* from the maximum of the shear storage
modulus G' versus the strain percentages.
[0098] Step a. of the above protocol for the determination of the
YS* serves to facilitate efficient dispersion during step b. The
citrus fiber in dry form may come at a variety of particle sizes.
Therefore, step a. includes milling of the citrus fiber so as to
obtain the fibers in the specified particulate form. Suitable
milling is provided by dry milling using a laboratory-scale Waring
blender. The buffered dispersion of step b. may be prepared using
any suitable buffer system. Preferably, a phosphate-based buffer is
used. In step c. the Silverson overhead mixer preferably is an L4RT
overhead mixer. G' is measured using any suitable parallel plate
rheometer, for example an ARG2 rheometer of TA Instruments. G' is
measured at various strain levels as will be understood by the
skilled person. A preferred way of establishing the YS* is by
following the protocol in the way described below. The above
protocol and the Examples provide methods of measuring the YS*.
However, the YS* may also be determined by a different protocol, as
long as that protocol would lead to the same physical result, i.e.
it would yield the same YS* for a particular dry citrus fiber
preparation as the above protocol.
[0099] The citrus fibres according to the tenth aspect of the
invention preferably have a YS* of at least 2 Pa, more preferably
at least 3 Pa, even more preferably at least 4 Pa and still more
preferably at least 4.5 Pa. The citrus fibers preferably have a
standardized yield stress of up to 50 Pa, and more preferably of up
to 20 Pa. Thus it is particularly preferred that the citrus fibers
in dry form have a standardized yield stress of between 2 Pa and 50
Pa, more preferably between 4 Pa and 20 Pa.
[0100] In an eleventh aspect, the present invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having a
transverse relaxation factor ("R.sub.2*") as measured by nuclear
magnetic resonance ("NMR") of at least 0.70. Preferably, the
R.sub.2* value of said composition is at least 0.75, more
preferably at least 0.80, even more preferably at least 0.85, most
preferably at least 0.90. Preferably, the moisture content of said
composition is at most 20 wt % relative to the total mass of
fibers, more preferably at most 12 wt %, even more preferably at
most 10 wt %, most preferably at most 8 wt %. Preferred examples
and preferred amounts of the additive as well as suitable A:F
ratios are presented above and will not be repeated herein.
[0101] In a twelfth aspect, the present invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having a
self-suspending capacity (SSC) of at least 9%. Preferably, the SSC
of the composition is at least 13%, more preferably at least 15%,
even more preferably at least 17%, yet even more preferably at
least 19%, and most preferably at least 21%. Preferably, the
moisture content of said composition is at most 20 wt % relative to
the total mass of fibers, more preferably at most 12 wt %, even
more preferably at most 10 wt %, most preferably at most 8 wt %.
Preferred examples and preferred amounts of the additive as well as
suitable A:F ratios are presented above and will not be repeated
herein.
[0102] In an thirteenth aspect, the present invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having a
yield stress (YS) of at least 2.0 Pa, said YS being measured on an
aqueous medium obtained by dispersing an amount of said composition
therein under a low shear stirring of less than 10000 rpm to obtain
a citrus fibers' concentration of 2 wt %. YS is measured on an
aqueous medium containing an amount of 2 wt % of citrus fibers,
i.e. relative to the total weight of the aqueous medium.
Preferably, the YS is at least 3.0 Pa, more preferably at least 5.0
Pa, even more preferably at least 8.0 Pa, yet even more preferably
at least 10.0 Pa, yet even more preferably at least 12.0 Pa, most
preferably at least 14.0 Pa. Preferably, the moisture content of
said composition is at most 20 wt % relative to the total mass of
fibers, more preferably at most 12 wt %, even more preferably at
most 10 wt %, most preferably at most 8 wt %. Preferred examples
and preferred amounts of the additive as well as suitable A:F
ratios are presented above and will not be repeated herein.
[0103] In a fourteenth aspect, the present invention provides a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having,
having a standardized yield stress (YS*) of at least 2.0 Pa wherein
the YS* is measured by [0104] a. providing the composition in a
particulate form wherein the particles can pass a 500 .mu.m sieve,
by milling the citrus fiber material using a Waring 8010EG
laboratory blender equipped with an SS110 Pulverizer Stainless
Steel Container using its low speed setting (18000 rpm) for 4 plus
or minus 1 seconds; sieving the milled material using an AS200
digital shaker from Retsch GmbH Germany with a sieve set of 10 mm,
500 .mu.m, 250 .mu.m and 50 .mu.m sieves, whilst shaking for 1
minute at an amplitude setting of 60; remilling and resieving the
particles larger than 500 .mu.m until they passed the 500 .mu.m
sieve and combining the sieved fractions; [0105] b. dispersing an
amount of the composition in particulate form so as to obtain 300
grams of an aqueous dispersion comprising 2 wt % of dry citrus
fiber by weight of the dispersion, wherein the dispersion is
buffered at pH 7.0, and whereby the fibers are dispersed using a
Silverson overhead mixer equipped with an Emulsor screen having
round holes of 1 mm diameter at 3000 rpm for 120 seconds; and
[0106] c. using a parallel plate rheometer determining the shear
storage modulus G' of the resultant dispersion as a function of the
strain percentage and establishing the yield stress from the
maximum of the shear storage modulus G' versus the strain
percentages.
[0107] Step a. of the above protocol for the determination of the
YS* serves to facilitate efficient dispersion during step b. The
composition of matter in dry form may come at a variety of particle
sizes. Therefore, step a. includes milling of the composition so as
to obtain the composition in the specified particulate form.
Suitable milling is provided by dry milling using a
laboratory-scale Waring blender. The buffered dispersion of step b.
may be prepared using any suitable buffer system. Preferably, a
phosphate-based buffer is used. In step c. the Silverson overhead
mixer preferably is an L4RT overhead mixer. G' is measured using
any suitable parallel plate rheometer, for example an ARG2
rheometer of TA Instruments. G' is measured at various strain
levels as will be understood by the skilled person. A preferred way
of establishing the YS* is by following the protocol in the way
described below. The above protocol and the Examples provide
methods of measuring the YS*. However, the YS* may also be
determined by a different protocol, as long as that protocol would
lead to the same physical result, i.e. it would yield the same YS*
for a particular dry citrus fiber preparation as the above
protocol.
[0108] The composition of matter in dry form according to the
fourteenth aspect of the invention preferably has a YS* of at least
2 Pa, more preferably at least 3 Pa, even more preferably at least
4 Pa and still more preferably at least 4.5 Pa. The composition of
matter in dry form preferably has a standardized yield stress YS*
of up to 50 Pa, and more preferably of up to 20 Pa. Thus it is
particularly preferred that the composition of matter in dry form
has a standardized yield stress YS* of between 2 Pa and 50 Pa, more
preferably between 4 Pa and 20 Pa. The preferences and examples
regarding the citrus fiber, the type and amount of additive in the
composition of matter according to this aspect of the invention are
as presented hereinabove for the composition of matter in dry form
comprising citrus fibers and an additive distributed between said
fibers according to the present invention.
[0109] In a fifteenth aspect, the present invention provides a
dispersion comprising citrus fibers dispersed in an aqueous medium,
said dispersion having a G' value of at least 50 Pa when measured
at a fiber concentration of 2 wt % relative to the total mass of
the dispersion. Preferably, said G' is at least 100 Pa, more
preferably at least 150 Pa, even more preferably at least 200 Pa,
yet even more preferably at least 250 Pa, most preferably at least
350 Pa. Preferably, said dispersion has a yield stress (YS) of at
least 2.0 Pa, more preferably at least 3.0 Pa, even more preferably
at least 5.0 Pa, yet even more preferably at least 8.0 Pa, yet even
more preferably at least 10.0 Pa, yet even more preferably at least
12.0 Pa, most preferably at least 14.0 Pa. Examples of dispersions
include without limitation suspensions, emulsions, foams and the
like. The citrus fibers in the dispersion may have a Brownian
motion or they may be fixed at an interface present in the aqueous
medium.
[0110] In a sixteenth aspect, the present invention provides a
method for manufacturing the inventive fibers and/or compositions
comprising the steps of: [0111] a. Homogenizing an aqueous slurry
of a source of citrus fibers to obtain an aqueous slurry of citrus
fibers; [0112] b. Contacting the aqueous slurry of citrus fibers
with an organic solvent to obtain a precipitate phase and a liquid
phase; wherein the precipitate is in the form of granules; [0113]
c. Separating said precipitate phase from the liquid phase to
obtain a semi-dry citrus fiber cake having a dry substance-content
of at least 10 wt % relative to the mass of said cake; [0114] d.
Comminuting said cake to obtain grains containing citrus fibers;
and mixing said grains with an additive to obtain a semi-dry
composition comprising citrus fibers and an additive; and [0115] e.
Desolventizing and/or dehydrating said semi-dry composition to
obtain a dry composition containing citrus fibers and an additive
and having a moisture content of preferably below 20 wt % relative
to the total weight of the fibers.
[0116] It is difficult to prepare a dry composition containing
citrus fibers without affecting the composition's dispersibility in
an aqueous media. This difficulty is attributed to many factors
(collectively referred to in literature as "hornification") such as
the formation of hydrogen bonds and/or lactone bridges between the
fibers. Hornification typically reduces the available free-surface
area of the fibers and/or strengthens the linkage between the
fibers, which in turn may reduce the capacity of the fibers to
absorb liquid and thus to disperse. Compositions containing
hornified dry citrus fibers either cannot be dispersed into an
aqueous medium, e.g. water, a water solution or a water suspension,
or they can be dispersed only by using high or ultra-high shear
mixing.
[0117] The method of the invention succeeded however in producing
dry compositions wherein the hornification of the citrus fibers was
largely prevented. Without being bound to any theory the inventors
believe that any of the G', R.sub.2*, SSC and YS as well as the
reduced deviations of STDEV from MAX characteristic to the
inventive fibers and inventive compositions may indicate a reduced
hornification of said fibers.
[0118] The method of the invention (the inventive method), contains
a step of homogenizing an aqueous slurry of a source of citrus
fibers ("source slurry"). The source of citrus fibers may be citrus
peel, citrus pulp, citrus rag or combinations thereof. The source
of citrus fibers may be a by-product obtained during the pectin
extraction process. Preferably, the source of the citrus fibers is
citrus peel; more preferably is de-pectinized citrus peel. Said
source slurry preferably comprises a dry substance content of at
least 2 wt %, more preferably at least 3 wt %, more preferably at
least 4 wt %. Preferably said dry substance content of said source
slurry is at most 10 wt %, more preferably at most 8 wt %, most
preferably at most 6 wt %.
[0119] The homogenization of the source slurry may be carried out
with a number of possible methods including, but not limited to,
high shear treatment, pressure homogenization, cavitation,
explosion, pressure increase and pressure drop treatments,
colloidal milling, intensive blending, extrusion, ultrasonic
treatment, and combinations thereof.
[0120] In a preferred embodiment, the homogenization of the source
slurry is a pressure homogenization treatment which may be carried
out with a pressure homogenizer. Pressure homogenizers typically
comprise a reciprocating plunger or piston-type pump together with
a homogenizing valve assembly affixed to the discharge end of the
homogenizer. Suitable pressure homogenizers include high pressure
homogenizers manufactured by GEA Niro Soavi of Parma Italy), such
as the NS Series, or the homogenizers of the Gaulin and Rannie
series manufactured by APV Corporation of Everett, Mass. (US).
During the pressure homogenization, the source slurry is subjected
to high shear rates as the result of cavitation and turbulence
effects. These effects are created by the source slurry entering a
homogenizing valve assembly which is part of a pump section of the
homogenizer at a high pressure (and low velocity). Suitable
pressures for the inventive method are from 50 bar to 2000 bar,
more preferably between 100 bar and 1000 bar. While not being bound
to any theory, it is believed that the homogenization causes
disruptions of the source of citrus fibers and its disintegration
into the fibrous component.
[0121] Depending on the particular pressure selected for the
pressure homogenization, and the flow rate of the source slurry
through the homogenizer, the source slurry may be homogenized by
one pass through the homogenizer or by multiple passes. In one
embodiment, the source slurry is homogenized by a single pass
through the homogenizer. In a single pass homogenization, the
pressure used is preferably from 300 bars to 1000 bars, more
preferably from 400 bars to 900 bars, even more preferably from 500
bars to 800 bars. In another preferred embodiment, the source
slurry is homogenized by multiple passes through the homogenizer,
preferably at least 2 passes, mere preferably at least 3 passes
through the homogenizer. In a multi-pass homogenization, the
pressure used is typically lower compared to a single-pass
homogenization and preferably from 100 bars to 600 bars, more
preferably from 200 bars to 500 bars, even more preferably from 300
bars to 400 bars.
[0122] The result of the homogenization step is an aqueous slurry
of citrus fibers ("fiber slurry") comprising a dry substance
content of fibers in essentially the same amount as the source
slurry. Said fiber slurry is then contacted with an organic
solvent. Said organic solvent should preferably be polar and
water-miscible to better facilitate water removal. Examples of
suitable organic solvents which are polar and water-miscible
include, without limitation, alcohols such as methanol, ethanol,
propanol, isopropanol and butanol. Ethanol and isopropanol arc
preferred organic solvents; isopropanol is the most preferred
organic solvent for use in the inventive method. The organic
solvent can be used in its 100% pure form or may be a mixture of
organic solvents. The organic solvent can also be used as a mixture
of the organic solvent and water, hereinafter referred to as an
aqueous solvent solution. The concentration of organic solvent in
said aqueous solvent solution is preferably from about 60 wt % to
about 100 wt % relative to the total weight of said solution, more
preferably between 70 wt % and 95 wt %, most preferably between 80
wt % and 90 wt %. In general, lower concentrations of the organic
solvent are suitable to remove water and water-soluble components
whereas increasing the concentration of said organic solvent also
helps in removing oil and oil-soluble components if desired. In one
embodiment, an organic solvent mixture containing a non-polar
organic (NPO) co-solvent and the organic solvent or the aqueous
solvent solution is used in the inventive method. The utilization
of the organic solvent mixture may improve for example the recovery
of oil-soluble components in the citrus pulp. Examples of suitable
NPO co-solvents include, without limitation, ethyl acetate, methyl
ethyl ketone, acetone, hexane, methyl isobutyl ketone and toluene.
The NPO co-solvents are preferably added in amounts of up to 20%
relative to the total amount of organic solvent mixture.
[0123] The fiber slurry is contacted with the organic solvent
preferably in a ratio slurry:solvent of at most 1:8, more
preferably at most 1:6, or most preferably at most 1:4. Preferably
said ratio is at least 1:0.5, more preferably at least 1:1, most
preferably at least 1:2. Preferably, said fiber slurry is contacted
with the organic solvent for at least 10 minutes, more preferably
for at least 20 minutes, most preferably for at least 30 minutes.
Preferably, said slurry is contacted with the organic solvent for
at most several hours, more preferably for at most 2 hours, most
preferably for at most 1 hour.
[0124] According to the invention, said fiber slurry is contacted
with said organic solvent to obtain a precipitate phase and a
liquid phase. The inventors observed that during contacting the
organic solvent with the fibers slurry, the fiber slurry releases
at least part of its water content into the organic solvent which
in turn causes the citrus fibers to precipitate. By "precipitate
phase" is herein understood a phase containing the majority of the
citrus fibers, e.g. more than 80% of the total amount of fibers,
preferably more than 90%, most preferably more than 98% and also
containing organic solvent and water. The precipitate phase usually
settles due to gravity forces. The precipitate phase typically has
a solid- or a gel-like appearance, i.e. it essentially maintains
its shape when placed on a supporting surface. By "liquid phase" is
herein understood a phase containing organic solvent and water. The
liquid phase may also contain some citrus fibers which did not
precipitate. According to the invention, the precipitate phase is
in the form of granules, preferably, millimeter-size granules.
Preferred granule sizes are between 1 mm and 100 mm, more
preferably between 5 mm and 50 mm. By "the size of a granule" is
herein understood the biggest dimension of said granule. The
formation of the precipitate phase into granules may be achieved
for example by bringing the fiber slurry under agitation into a
container containing the organic solvent or by pouring said slurry
in the organic solvent. The amount of agitation typically dictates
the size of the formed granules. It was observed that by forming
granules, the subsequent water removal from said granules is
facilitated. Without being bound to any theory, it is believed that
the formation of granules also aids in preserving and/or increasing
the free surface area of the citrus fibers available for water
binding and may also avoid a collapse of the fibers.
[0125] The precipitate phase is subsequently separated from the
liquid phase to obtain a semi-dry citrus fibers cake ("fiber
cake"). Said separation can be achieved using known methods such as
centrifugation, filtration, evaporation and combinations
thereof.
[0126] To increase the dry substance content, steps b) and c) of
the inventive method can be repeated at least one time, preferably
before carrying out step d). The fiber cake can also be subjected
to an extraction step. A preferred extraction method is pressing,
e.g. with a normal press, a screw press or an extruder. A more
preferred extraction method is pressure filtration using a volume
chamber filter press or a membrane filter press; pressure filters
being sold for example by BHS Sonthofen, DE. Two-sided liquid
removal is recommended for the pressure filtration since more
filtering area is available per volume of the fiber cake.
[0127] The fiber cake is semi-dry, i.e. it has a dry substance
content of preferably at least 10 wt %, more preferably of at least
15 wt %, or most preferably of at least 20 wt % relative to the
mass of said cake. Preferably, said cake has a liquid-content of at
most 50 wt %, more preferably at most 40 wt %, most preferably at
most 30 wt % relative to the total mass of said cake. The liquid
typically contains organic solvent and water.
[0128] In accordance with the invention, the fiber cake is
comminuted to obtain grains containing citrus fibers ("fiber
grains"), said grains preferably having a diameter of at most 100
mm, more preferably at most 50 mm, even more preferably at most 30
mm, yet even more preferably at most 10 mm, yet even more
preferably at most 5 mm, most preferably at most 3 mm. With "grain
diameter" is herein understood the largest dimension of the grain.
The diameter may be determined using a microscope equipped with
graticule. Cutters may be used to cut the fiber cake into grains.
Alternatively, the fiber cake can subjected to milling and/or
grinding in order to form it into grains. Examples of suitable
means to comminute the fiber cake include without limitation a
cutter mill, a hammer mill, a pin mill, a jet mill and the
like.
[0129] The fiber grains are mixed with an additive to obtain a
semi-dry composition comprising citrus fibers and the additive.
Examples of suitable additives as well as preferred choices are
given above and will not be repeated herein. Mixing the fiber
grains with the additive can be effected with known means in the
art, examples thereof including without limitation a malaxer, a
transport screw, an air-stream agitation mixer, a paddle mixer, a
Z-mixer, a tumble mixer, a high speed paddle mixer, a power blender
and the like. The additive may be provided in a solid form or in
solution. Preferably, the additive is provided in a solid form,
more preferably as a powder, even more preferably as a powder
having an average particle size ("APS") of between 100 and 500
.mu.m, more preferably between 150 and 300 .mu.m; the APS can be
determined by ASTM C136-06.
[0130] The semi-dry composition is subjected to a desolventizing
and or dehydrating step wherein the organic solvent and/or the
water are extracted from said composition. Preferably, the
inventive method contains both steps of desolventizing and
dehydration. It was surprisingly observed that during the organic
solvent and/or water extraction, the hornification of citrus fibers
was largely prevented. Without being bound to any theory, the
inventors attributed the reduced hornification to the careful
pre-processing of the composition prior to said extraction as
detailed in steps a) to d) of the inventive method.
[0131] Desolventisation and dehydration of said composition can be
carried out with a desolventizer which removes organic solvent
and/or water from the composition and may also enable the organic
solvent to be reclaimed for future use. Desolventizing also ensures
that the obtained dry composition is safe for milling and
commercial use. The desolventizer can employ indirect heat to
remove the organic solvent from the composition; the advantage of
using said indirect heal is that significant amounts of organic
solvents can be extracted. Also, direct heat can be provided for
drying, e.g. by providing hot air from flash dryers or fluidized
bed dryers. Direct steam may be employed, if desired, to remove any
trace amounts of organic solvent remaining in the composition.
Vapors from the desolventizer preferably are recovered and fed to a
still to reclaim at least a portion of the organic solvent.
[0132] Retention times for the desolventizing and/or dehydrating
step may vary over a wide range but can be about 5 minutes or less.
Suitable temperatures at which said desolventizing and dehydrating
step is carried out depend on such factors as the type of organic
solvent and most often ranges from about 4.degree. C. to about
85.degree. C. at atmospheric pressure. Temperatures can be
appropriately increased or decreased for operation under supra- or
sub-atmospheric pressures. Optionally, techniques such as
ultrasound are used for enhancing efficiency of the desolventizing
and dehydrating. By maintaining a closed system, solvent losses can
be minimized. Preferably, at least about 70 wt % of the organic
solvent is recovered and reused.
[0133] Dehydration can be effected with known means in the art,
examples thereof including without limitation paddle driers,
fluidized bed driers, stirred vacuum driers, drum driers, plate
driers, belt driers, microwave driers and the like. Preferably, the
dehydration temperature is at most 100.degree. C., more preferably
at most 80.degree. C., most preferably at most 60.degree. C.
Preferably, the dehydration temperature is at least 30.degree. C.,
more preferably at least 40.degree. C., most preferably at least
50.degree. C.
[0134] The desolventizing and/or dehydrating step are carried out
to obtain a dry composition comprising citrus fibers and an
additive, said dry composition having a moisture content of at most
20 wt % relative to the total weight of the fibers, preferably at
most 15 wt %, more preferably at most 12 wt %, even more preferably
at most 10 wt %, most preferably at most 8 wt %.
[0135] Optionally, the method of the invention further comprises a
step of removing said additive and/or classifying the dry
composition to obtain the desired particle size and/or packing the
dry composition.
[0136] In a preferred embodiment, the inventive method comprises a
classification step of the dry composition which may improve the
homogeneity of the powder, narrow particle size distribution and
improve degree of rehydration. Classification may be carried out
using either a static or dynamic classifier. The inventive method
may further comprise a packaging step of the dry composition.
[0137] In another preferred embodiment, the additive is extracted
from the dried and/or classified composition as obtained at steps
f) and/or g), respectively to obtain dry citrus fibers. To aid in
the extraction of the additive, preferably, an additive is used
that has a boiling point of less than the degradation temperature
of the citrus fibers. The extraction may be performed by washing
the additive with a suitable solvent other than water. The
extraction is preferably performed by subjecting said composition
to an extraction temperature between the boiling point of the
additive and the degradation temperature of the citrus fibers and
allowing the additive to evaporate; preferably the evaporation is
carried out under vacuum. Preferably, said additive has a boiling
point of at most 250.degree. C., more preferably at most
200.degree. C., most preferably at most 150.degree. C. The boiling
points of various materials are listed in the CRC Handbook of
Chemistry and Physics or alternatively, ASTM D1120 may be used to
determine said boiling point. Preferably the extraction temperature
is between 100 and 300.degree. C., more preferably between 100 and
250.degree. C., most preferably between 100 and 200.degree. C.
Examples of additives having such reduced boiling points include
low molecular weight polyols, e.g. polyether polyols, ethylene
glycols, and the like. By low molecular weight is herein understood
an M.sub.w of between 50 and 500. The use of such extractable
additives enables the manufacturing of the inventive fibers.
Alternatively, dry citrus fibers may be obtained with the inventive
method by skipping in step d) the addition of the additive by
mixing. Dry cellulose fibers may also be obtained with the method
of the invention by choosing an appropriate source of cellulose
fibers to be processed.
[0138] The dry composition comprising the citrus fibers and the
additive is preferably milled and/or classified to obtain a powder
having an average particle size of preferably at least 50 .mu.m,
more preferably at least 150 .mu.m, most preferably at least 250
.mu.m. Preferably said average particle size is at most 2000 .mu.m,
more preferably at most 1000 .mu.m, most preferably at most 500
.mu.m. Said average particle size may be determined by ASTM
C136-06.
[0139] In a seventeenth aspect, the invention relates to a
composition of matter in dry form obtainable by the method for
manufacturing the composition according to the sixteenth aspect of
the present invention.
[0140] The invention will be further detailed in the following
exemplary embodiments, without being however limited thereto.
[0141] In a first embodiment, the inventive composition of matter
in dry form comprises citrus fibers and an additive distributed
between said fibers, wherein said composition has a transverse
relaxation factor (R.sub.2*) of at least 0.70, more preferably of
at least 0.75, more preferably of at least 0.85, most preferably of
at least 0.90, wherein when dispersing said composition with a low
shear stirring of less than 10000 rpm in an aqueous medium to yield
a fiber concentration of 2 wt %, the obtained dispersion has a G'
value of at least 50 Pa. Preferably, the dispersion is carried out
with a low shear stirring of at most 8000 rpm, more preferably at
most 5000 rpm, most preferably at most 3000 rpm. Preferably, the
A:F ratio of the composition is between 0.01:1 and 10:1 by weight,
more preferably between 0.1:1 and 9:1 by weight, most preferably
between 0.4:1 and 8:1 by weight. Preferably, the citrus fibers did
not undergo any substantial chemical modification. Preferably, the
additive is chosen from the group consisting of fructose, mannose,
galactose, glucose, talose, gulose, allose, altrose, idose,
arabinose, xylose, lyxose, ribose, sucrose, maltose, lactose,
glycerol, sorbitol, starch and combinations thereof.
[0142] In a second embodiment, the inventive composition of matter
in dry form comprises citrus fibers and an additive distributed
between said fibers, wherein said composition has a SSC of at least
9% and a transverse relaxation factor (R.sub.2*) of at least 0.70.
Preferably, the SSC of the composition is at least 13%, more
preferably at least 15%, even more preferably at least 17%, yet
even more preferably at least 19%, and most preferably at least
21%. Preferably, the R.sub.2* value of said composition is at least
0.75, more preferably at least 0.80, even more preferably at least
0.85, most preferably at least 0.90. Preferably, the A:F ratio of
the composition is between 0.01:1 and 10:1 by weight, more
preferably between 0.1:1 and 9:1 by weight, most preferably between
0.4:1 and 8:1 by weight. Preferably, the citrus fibers did not
undergo any substantial chemical modification. Preferably, the
additive is chosen from the group consisting of fructose, mannose,
galactose, glucose, talose, gulose, allose, altrose, idose,
arabinose, xylose, lyxose, ribose, sucrose, maltose, lactose,
glycerol, sorbitol, starch and combinations thereof.
[0143] In a third embodiment, the citrus fibers of the invention
have a transverse relaxation factor ("R.sub.2*") as measured by
nuclear magnetic resonance ("NMR") of at least 0.7 and a
self-suspending capacity (SSC) of at least 9%. Preferably, the
R.sub.2* value of said dry cellulose fibers is at least 0.9, even
more preferably at least 1.1, and most preferably at least 1.2.
Preferably, the SSC of the dry cellulose fibers is at least 12,
even more preferably at least 15, yet even more preferably at least
17 and most preferably at least 19. Preferably, the moisture
content of the dry citrus fibers is at most 20 wt % relative to the
total mass of fibers, more preferably at most 12 wt %, even more
preferably at most 10 wt %, most preferably at most 8 wt %.
[0144] In a fourth embodiment, the invention relates to citrus
fibers in dry form having a storage modulus (G') of at least 50 Pa,
said G' being measured on an aqueous medium containing an amount of
2 wt % citrus fibers dispersed therein under a low-shear stirring
of less than 10000 rpm, said fibers preferably having a transverse
relaxation factor ("R.sub.2* ") as measured by nuclear magnetic
resonance ("NMR") of at least 0.35, said fibers preferably having a
self-suspending capacity (SSC) of at least 5%, said fibers
preferably having a yield stress (YS) of at least 2.0 Pa, said YS
being measured on an aqueous medium containing an amount of 2 wt %
citrus fibers dispersed therein under a low-shear stirring of less
than 10000 rpm. Preferably, said G' is at least 75 Pa, more
preferably at least 100 Pa, even more preferably at least 125 Pa,
yet even more preferably at least 150 Pa, most preferably at least
170 Pa. Preferably, the stirring used to achieve the dispersion of
said citrus fibers in the aqueous medium is at most 8000 rpm, more
preferably at most 5000 rpm, most preferably at most 3000 rpm.
Preferably, said citrus fibers contain an amount of water of at
most 12 wt %, more preferably at most 10 wt %, or most preferably
at most 8 wt %. Preferred ranges for R.sub.2*, SSC and YS are
presented herein above where the third, fourth and fifth aspects of
the invention, respectively, are detailed and will not be further
repeated herein.
[0145] In a fifth embodiment, the invention relates to a
composition of matter in dry form comprising citrus fibers and an
additive distributed between said fibers, said composition having a
storage modulus (G') of at least 50 Pa, said G' being measured on
an aqueous medium obtained by dispersing an amount of said
composition therein under a low shear stirring of less than 10000
rpm to obtain a citrus fibers' concentration of 2 wt % relative to
the total amount of the aqueous medium, said composition preferably
having a transverse relaxation factor ("R.sub.2*") as measured by
nuclear magnetic resonance ("NMR") of at least 0.70, said
composition preferably having a self-suspending capacity (SSC) of
at least 9%, said composition preferably having a yield stress (YS)
of at least 2.0 Pa, said YS being measured on an aqueous medium
obtained by dispersing an amount of said composition therein under
a low shear stirring of less than 10000 rpm to obtain a citrus
fibers' concentration of 2 wt %. Preferably, the composition
contains an amount of water of at most 12 wt %, more preferably at
most 10 wt %, or most preferably at most 8 wt %. Preferably, the
composition has an additive:fiber (A:F) ratio of between 0.01:1.0
and 10.0:1.0 by weight, more preferably between 0.1:1.0 and 9.0:1.0
by weight, most preferably between 0.4:1.0 and 8.0:1.0 by weight.
Preferably, the additive is chosen from the group consisting of
glucose, sucrose, glycerol and sorbitol. Preferred ranges for G',
R.sub.2*, SSC and YS are presented herein above where the second,
sixth, seventh and eighth aspects of the invention, respectively,
are detailed and will not be further repeated herein.
[0146] It was observed that the inventive compositions have an
optimal viscoelastic stability, e.g. fewer fluctuations of
compositions' viscoelastic behavior. The ability of the inventive
compositions to smoothen out viscoelastic fluctuations may enable a
more reliable processing thereof, which in turn may lead to optimal
quality of various products containing said composition, e.g.,
food, feed, personal care and pharmaceutical products.
[0147] The inventive fibers und the inventive compositions are
suitably used in the production of a large variety of food
compositions. Examples of food compositions comprising thereof, to
which the invention relates, include: luxury drinks, such as
coffee, black tea, powdered green tea, cocoa, adzuki-bean soup,
juice, soya-bean juice, etc.; milk component-containing drinks,
such as raw milk, processed milk, lactic acid beverages, etc.; a
variety of drinks including nutrition-enriched drinks, such as
calcium-fortified drinks and the like and dietary fiber-containing
drinks, etc.; dairy products, such as butter, cheese, yogurt,
coffee whitener, whipping cream, custard cream, custard pudding,
etc.; iced products such as ice cream, soft cream, lacto-ice, ice
milk, sherbet, frozen yogurt, etc.; processed fat food products,
such as mayonnaise, margarine, spread, shortening, etc.; soups;
stews; seasonings such as sauce, TARE, (seasoning sauce),
dressings, etc.; a variety of paste condiments represented by
kneaded mustard; a variety of fillings typified by jam and flour
paste; a variety or gel or paste-like food products including red
bean-jam, jelly, and foods for swallowing impaired people; food
products containing cereals as the main component, such as bread,
noodles, pasta, pizza pie, corn flake, etc.; Japanese, US and
European cakes, such as candy, cookie, biscuit, hot cake,
chocolate, rice cake, etc.; kneaded marine products represented by
a boiled fish cake, a fish cake, etc.; live-stock products
represented by ham, sausage, hamburger steak, etc.; daily dishes
such as cream croquette, paste for Chinese foods, gratin, dumpling,
etc.; foods of delicate flavor, such as salted fish guts, a
vegetable pickled in sake lee, etc.; liquid diets such as tube
feeding liquid food, etc.; supplements; and pet foods. These food
products are all encompassed within the present invention,
regardless of any difference in their forms and processing
operation at the time of preparation, as seen in retort foods,
frozen foods, microwave foods, etc.
[0148] The invention also provides a food composition in dry form,
comprising the citrus fibre according to the invention and/or the
composition of matter in dry form according to the invention. Such
a food composition in dry form preferably comprises a composition
of matter in dry form, wherein said composition of matter comprises
citrus fibres and an additive distributed between said fibres. It
is particularly preferred that the additive is sucrose and that the
ratio A:F of additive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0
by weight.
[0149] It was surprisingly found that the citrus fibres in dry form
of the present invention and the composition in dry form comprising
citrus fibres and an additive of the present invention can be
readily dispersed in an aqueous medium. Therefore, these fibres and
compositions can advantageously be used in the manufacture of
compositions comprising dispersed citrus fibres. Traditionally,
exploitation of the properties of citrus fibres to prepare a
composition with excellent rheological properties requires the use
of equipment that can impart high to very high shear during the
manufacture of the composition. Such equipment is usually costly,
and in operation uses a relatively large amount of energy.
Moreover, such high shear levels may be detrimental to the
properties of other constituents of such a composition. In
particular if the product is a food product, for instance, high
shear treatment may adversely affect the taste, flavour and or
other organoleptic properties provided by other ingredients. Using
the citrus fibres or composition in dry form comprising citrus
fibres of the present invention allows the manufacture of
intermediate or end products with dispersed citrus fibres whilst
requiring a lower amount of shear energy to obtain the same or even
better benefits of dispersed citrus fibres in the manufactured
product. Thus, the citrus fibres and composition of matter in dry
form of the present invention provide increased flexibility and
efficiency in such product manufacture.
[0150] Consequently, the present invention in an eighteenth aspect
provides a method for preparing a composition comprising an aqueous
phase wherein the aqueous phase comprises dispersed citrus fibres,
wherein the method comprises the step of dispersing a source of
citrus fibres in an aqueous medium thereby to form at least part of
said first aqueous phase; and wherein the source of citrus fibres
is citrus fibres in dry form according to the present invention or
the composition in dry form comprising citrus fibres and an
additive distributed between said fibres according to the present
invention. The aqueous phase may be prepared with a variety of
rheological properties, and may for instance be selected to have
any consistency between highly fluid (water thin) to a highly
viscous, or spoonable, or gelled consistency. The level of citrus
fibre in the aqueous phase may suitably be adjusted to the
rheological requirements for the particular product. Typically, the
aqueous phase may comprise between 0.01 and 10 wt-% of dispersed
citrus fibres with respect to the weight of the aqueous phase, and
preferably comprises between 0.05 and 5 wt-%, even more preferably
between 0.1 and 3 wt-% of dispersed citrus fibres. The source of
citrus fibres that is used in the present method preferably is a
composition of matter in dry form comprising citrus fibre and an
additive distributed between said citrus fibres. It is particularly
preferred that the additive is sucrose and that the ratio A:F of
additive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight.
It is likewise preferred that the composition of citrus fibre used
as the source of citrus fibre has a Fibre Availability Parameter of
at least 0.70 Hz, more preferably 0.8 Hz and even more preferably
at least 0.9 Hz.
[0151] The present method is particularly useful in the preparation
emulsified products. Therefore, the method preferably is a method
for preparing a composition in the form of an oil-in-water
emulsion. The oil-in-water emulsion is preferably an edible
emulsion. The edible oil-in-water emulsion preferably comprises
from 5 to 50 wt-% of oil. The oil typically is an edible oil. As
understood by the skilled person such edible oils typically
comprise triglycerides, usually mixtures of such triglycerides.
Typical examples of edible oils include vegetable oils including
palm oil, rapeseed oil, linseed oil, sunflower oil and oils of
animal origin.
[0152] The present method is also useful to prepare emulsions in
the form of a dressing or a similar condiment, because it is
suitable to provide rheological properties that are generally
considered desirable for dressings. Since such dressings are
typically acidic in nature, the present method is preferably for
preparing a composition in the form of an oil-in-water emulsion
wherein the composition in the form of an oil-in-water-emulsion
comprises from 15 to 50 wt-% of oil and from 0.1 to 10 wt-% of
acid. It is particularly preferred that the composition in the form
of an oil-in-water emulsion is a mayonnaise.
[0153] The present method is also useful in the preparation of
emulsified products which comprise proteins. Thus, the method is
preferably a method for preparing a composition in the form of an
oil-in-water emulsion, wherein the composition in the form of an
oil-in-water emulsion comprises protein, wherein the amount of
protein is preferably front 0.1 to 10 wt %, more preferably from
0.2 to 7 wt % and even more preferably from 0.25 to 4 wt % by
weight of the composition. The protein may advantageously include
milk protein, which is a desirable component in many food
compositions. Thus, the protein preferably comprises at least 50 wt
% milk protein, more preferably at least 70 wt %, even more
preferably at least 90 wt % and still more preferably consists
essentially of milk protein. The suitability of the present method
to impart desirable characteristics deriving from citrus fibres to
an aqueous medium, in the presence of both emulsified oil and milk
protein, make the method suitable for the preparation of
ready-to-drink milk teas. Hence, the present method preferably is a
method for the preparing a composition in the form of an
oil-in-water emulsion, wherein the composition in the form of an
oil-in-water emulsion is a ready-to-drink tea-based beverage. The
term "ready-to-drink tea beverage" refers to a packaged tea-based
beverage, i.e. a substantially aqueous drinkable composition
suitable for human consumption. Preferably the beverage comprises
at least 85% water by weight of the beverage, more preferably at
least 90%. Ready-to-drink (RTD) milk tea beverages usually contain
milk solids like for example milk protein and milk fat that give
the beverages certain organoleptic properties like for example a
`creamy mouthfeel`. Such an RTD milk tea beverage preferably
comprises at least 0.01 wt % tea solids on total weight of the
beverage. More preferably the beverage comprises from 0.04 to 3 wt
% tea solids, even more preferably from 0.06 to 2%, still more
preferably from 0.08 to 1 wt % and still even more preferably from
0.1 to 0.5 wt %. The tea solids may be black tea solids, green tea
solids or a combination thereof. The term "tea solids" refers to
dry material extractable from the leaves and/or stem of the plant
Camellia sinensis, including for example the varieties Camellia
sinensis var. sinensis and or Camellia sinensis var. assamica.
Examples of tea solids include polyphenols, caffeine and amino
acids. Preferably, the tea solids are selected from black tea,
green tea and combinations thereof and more preferably the tea
solids are black tea solids. In case the method is a method for the
preparation of a RTD milk tea beverage, the source of citrus fibres
that is used preferably is a composition of matter in dry form
comprising citrus fibre and an additive distributed between said
citrus fibres. It is particularly preferred that the additive is
sucrose and that the ratio A:F of additive to citrus fibre is 0.10
to 1.0 and 3.0 to 1.0 by weight. It is likewise preferred that the
composition of citrus fibre used as the source of citrus fibre has
a Fibre Availability Parameter of at least 0.70 Hz, more preferably
0.8 Hz and even more preferably at least 0.9 Hz.
[0154] The present method is also useful for preparing edible
compositions comprising an aqueous phase, which optionally comprise
an oil-based constituent, but which do not require the presence of
the oil-based constituent. Thus, the present method for preparing a
composition wherein the composition comprises at least a first
aqueous phase comprising dispersed citrus fibres preferably is a
method for preparing a load composition comprising a flavour base
and from 0 wt-% to 5 wt-% of oil, more preferably from 0 wt-% to 2
wt-%, even more preferably from 0 wt-% to 1 wt-% and even more
preferably from 0 wt-% to 0.5 wt-% of oil with respect to the
weight of the composition. Herein, "flavour base" means the base of
the food composition that is responsible for the identification of
the product. The flavour base preferably is a fruit- or
vegetable-based product, or a mixture thereof. The present method
is especially useful for imparting desirable rheological
characteristics to tomato-based products. Therefore, more
preferably the flavour base is a tomato paste, a tomato puree, a
tomato juice, a tomato concentrate or a combination thereof, and
ever more preferably it is a tomato paste. Thus, present method for
preparing a composition comprising an aqueous phase, preferably is
a method for the preparation of a composition wherein the
composition is a tomato sauce or a tomato ketchup.
[0155] The present method for preparing a composition, wherein the
composition comprises an aqueous phase comprising dispersed citrus
fibres is not limited to the preparation of edible or food
compositions. The properties of the citrus fibres in dry form and
the composition of matter in dry form of the present invention make
the present method particularly suitable to impart desired
rheological properties onto compositions comprising a surfactant
system. Thus, the present invention also provides a method for
preparing a composition comprising a surfactant system, wherein the
composition comprises at least a first aqueous phase comprising
dispersed citrus fibres, wherein the method comprises the step of
dispersing a source of citrus fibres in an aqueous medium thereby
to form at least part of said first aqueous phase; and wherein the
source of citrus fibres is citrus fibres in dry form according to
the present invention or the composition of matter in dry form
comprising citrus fibres and an additive distributed between said
fibres according to the present invention. Preferably, the source
of citrus fibres is a composition of matter in dry from comprising
citrus fibres and an additive distributed between said fibres. It
is particularly preferred that the additive is sucrose and that the
ratio A:F of additive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0
by weight. It is likewise preferred that the composition of citrus
fibre used as the source of citrus fibre has a Fibre Availability
Parameter of at least 0.70 Hz, more preferably 0.8 Hz and even more
preferably at least 0.9 Hz.
[0156] The composition comprising a surfactant system preferably
comprises the surfactant system in an amount of 0.1 to 50 wt-%,
more preferably from 5 to 30 wt-%, and even more preferably from 10
to 25 wt-% with respect to the weight of the composition. There are
few limitations on the type or the amount of the surfactants. In
general, the surfactants may be chosen from the surfactants
described in well-known textbooks like "Surface Active Agents" Vol.
1, by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz,
Perry & Berch, Interscience 1958, and/or the current edition of
"McCutcheon's Emulsifiers and Detergents" published by
Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H.
Stache, 2.sup.nd Edn., Carl Hauser Verlag, 1981; "Handbook of
Industrial Surfactants" (4.sup.th Edn.) by Michael Ash and Irene
Ash; Synapse Information Resources, 2008. The type of surfactant
selected may depend on the type of application for which the
product is intended. The surfactant system may comprise one type of
surfactant, or a mixture of two or more surtactants. Synthetic
surfactants preferably form a major part of the surfactant system.
Thus, the surfactant system preferably comprises one or more
surfactants selected from one or more of anionic surtactants,
cationic surfactants, non-ionic surfactants, amphoteric surfactants
and zwitterionic surfactants. More preferably, the one or more
detergent surfactants are anionic, nonionic, or a combination of
anionic and nonionic surfactants. Mixtures of synthetic anionic and
nonionic surfactants, or a wholly anionic mixed surfactant system
or admixtures of anionic surfactants, nonionic surtactants and
amphoteric or zwitterionic surfactants may all be used according to
the choice of the formulator for the required cleaning duty and the
required dose of the cleaning composition. Preferably, the
surfactant system comprises one or more anionic surfactants. More
preferably, the surfactant system comprises one or more anionic
surfactants selected from the group consisting of lauryl ether
sulfates and linear alkylbenzene sulphonates.
[0157] For certain applications the composition comprising a
surfactant system preferably also comprises from 1 to 8 wt-% of an
inorganic salt, preferably selected from sulfates and carbonates,
more preferably selected from MgSO.sub.4 and Na.sub.2SO.sub.4 and
even more preferably MgSO.sub.4. The composition comprising a
surfactant system may be any product comprising surfactants.
Preferably the composition comprising a surfactant system is a
cleaning composition, more preferably a hand dish wash composition.
In view of the favourable properties that the present method
provides to the composition comprising the surfactant system, the
composition preferably further comprises suspendable particles
and/or air bubbles.
[0158] According to a nineteenth aspect, the invention also relates
to a composition comprising a surfactant system wherein the
composition also comprises the citrus fibre according to the
invention and/or the composition of matter in dry form according to
the invention. Herein, the surfactant system is as described above.
The composition comprising a surfactant system preferably is a
composition in dry form. Such a composition in dry form preferably
comprises a composition of matter in dry form, wherein said
composition of matter comprises citrus fibres and an additive
distributed between said fibres. It is particularly preferred that
the additive is sucrose and that the ratio A:F of additive to
citrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight.
Methods of Measurement
[0159] Sample Preparation: It is preferred that prior to any
characterization, all citrus fibers' and compositions' samples made
in accordance with the Examples and Comparative Experiments
presented herein below, are milled using a Waring 8010EG laboratory
blender (Waring Commercial, USA) equipped with a SS110 Pulverizer
Stainless Steel Container using its low speed setting (18000 rpm)
for 3 to 5 sec. The milled samples were sieved using a AS200
digital shaker from Retsch GmbH Germany with a sieve set of 10 mm,
500 .mu.m, 250 .mu.m and 50 .mu.m sieves (50.times.200 mm), sieving
conditions: 1 min at amplitude setting 60. Particles larger than
500 .mu.m may be milled again until they pass sieve 500 .mu.m.
[0160] Moisture content ("MC"): The moisture content was determined
by weighing a milled sample placed in a pre-dried vessel and
subsequently heating the vessel containing the sample overnight in
an oven at 105.degree. C. The moisture content (in wt %) was
calculated as (A.sub.1-A.sub.2)/A.sub.1.times.100 where A.sub.1 was
the weight of the sample before drying in the oven and A.sub.2 was
the weight of the resulted dried sample, unless indicated
otherwise. [0161] Dry substance content ("DS") is measured
according to formula:
[0161] DS(%)=100%-MC(%) When the weight of anhydrous fibers in a
composition needs to be determined, the above procedure can be
utilized while correcting the moisture content for the additive
content in the sample. [0162] Standard deviation is computed
according to the following formula:
[0162] ( x - x _ ) 2 ( n - 1 ) ##EQU00002## where x is the sample
mean average and n is the sample size. [0163] R.sub.2*
Measurements: [0164] Sample preparation for NMR measurements:
dispersions having fiber concentrations of 0.50 wt % were prepared
by rehydrating milled and sieved samples in demineralized water.
For each dispersion, an appropriate amount of sample (correcting
for moisture and additive content) was weighed in 500 ml plastic
pots and demineralized water was added to yield a total weight of
250 g. After subsequently adding 0.24 g of a preservative (Nipacide
BIT20) and adjusting the pH to 3.6.+-.0.1 using aqueous HCl, a
further amount of demineralized water was added to yield a mixture
with a total weight of 300 g. This mixture was homogenized at room
temperature using a Silverson L4RT overhead batch mixer equipped
with an Emulsor Screen (with round holes of about 1 mm diameter)
operated for 2 min (120 sec.) at 3000 rpm. The mixtures were
allowed to equilibrate overnight, after which the pH was
standardized at 3.3.+-.1 using concentrated HCl. [0165]
Calibration: an aliquot of the resulting pH-standardized mixture
was transferred directly to a 18 cm flat bottom NMR tube of 10 mm
diameter at a filling height of about 1 cm ensuring that upon
placement of the sample in the NMR spectrometer, the fill height is
within the region where the RF field of the coil of the NMR
spectrometer is homogeneous. In order to do a background correction
(calibration), another aliquot was centrifuged (Eppendorf
Centrifuge 5416) for 10 min in a 2 ml Eppendorf cup at a relative
centrifugation force of 15000 to separate the fibers from the
liquid. The top layer (supernatant) of the centrifuged mixture
without the fibre (hereinafter referred to as the "matrix reference
sample") was transferred to a 18 cm flat bottom NMR tube at a
filling height of 1 cm. Both the mixture and the matrix reference
sample were incubated and equilibrated at 20.degree. C. for 10 min.
prior to the NMR measurement. The "relative centrifugal force", is
defined as r.times..omega..sup.2/g, where g=9.8 ms.sup.-2 is the
Earth's gravitational acceleration, r is the rotational radius of
the centrifuge, .omega. is the angular velocity in radians per unit
time. The angular velocity is .omega.=rpm.times.2.pi./60, where rpm
is the number of "revolutions per minute" of the centrifuge. [0166]
NMR measurement: Carr Purcell Meiboom Gill (CPMG) relaxation decay
data were collected for each mixture and for each matrix reference
sample, A Bruker MQ20 Minispec was used operating at a resonance
frequency for protons of 20 MHz, equipped with a variable
temperature probe-head stabilized at 20.degree. C. Measurements
were performed using a CPMG T.sub.2 relaxation pulse sequence to
observe the relaxation decay at 20.degree. C. (See Effects of
diffusion on free precession in nuclear magnetic resonance
experiments, Carr, H. Y., Purcell, E. M., Physical Review, Volume
94, Issue 3, 1954, Pages 630-638/Modified spin-echo method for
measuring nuclear relaxation times, Meiboom, S., Gill, D., Review
of Scientific Instruments, Volume 29, Issue 8, 1958, Pages
688-691). Data were collected with the 180.degree. pulse spacing
set to 200 .mu.s (microseconds), a recycle delay time of 30 sec, a
180.degree.-pulse length of 5 .mu.s and using 14.7k
180.degree.-pulses. The sequence deploys a phase cycle and complex
mode detection. Prior to measurement, the suitability of the NMR
system for these measurements (in terms of field homogeneity etc.)
was checked by verifying that the T.sub.2* of pure water was >2
ms. [0167] NMR data analysis (R.sub.2* extraction): Data were
processed with Matlab using a singular value decomposition to phase
correct the quadrature data ("Towards rapid and unique curve
resolution of low-field NMR relaxation data; trilinear SLICING
versus two-dimensional curve fitting", Pedersen, H. T., Bro, R.,
Engelsen, S. B., Journal of Magnetic Resonance. August 2002;
157(1), Pages 141-155. DOI: 10.1006/jmre.2002.2570). The resulting,
phase-corrected data were Inverse Laplace Transformed into a
T.sub.2 spectrum using the Matlab non-negative least square
constraints function Isqnonneg (Lawson, C. L. and R. J. Hanson,
Solving Least Squares Problems, Prentice-Hall, 1974, Chapter 23, p.
161) with boundaries set for T.sub.2, requiring T.sub.2 to be in
the range of 0.01 to 10 seconds and with the regularization
parameter lambda set to 0.2. R.sub.2* was determined as follows:
from the T.sub.2 distribution curve for a particular mixture, the
peak corresponding to the water protons of which T.sub.2 is
averaged by exchange between the bulk water phase and the surface
of the fiber material originating from the fiber mass was
identified. Without being bound to any theory, the inventors
believe that the exchange (and resulting averaging) is due to
diffusion and chemical exchange between bulk and fibers' surface
sites. The peaks of the bulk water phase are easily distinguished,
as typically they are the peaks with the highest intensity. The
peak corresponding to the bulk water phase in the matrix reference
sample was similarly identified. The average T.sub.2 value was
determined by calculating the intensity-weighted average of the
peak. R.sub.2 is defined as the inverse of this average T.sub.2,
i.e. R.sub.2=1/T.sub.2 and is expressed in Hz. The R.sub.2* for a
given mixture is calculated as the difference between the R.sub.2
of the mixture and R.sub.2 of the matrix reference sample. Thus,
R.sub.2* is a measure for the bulk water interaction with the
available fiber surface (K. R. Brownstein, C. E. Tarr, Journal of
Magnetic Resonance (1969) Volume 26, Issue 1, April 1977, Pages
17-24). The characterization of the citrus fibers and compositions
of the Examples and Comparative Experiments in terms of their
R.sub.2* is presented in Table 1c. [0168] Rheology Measurements
[0169] Sample preparation for theology measurements: dispersions
were made by rehydrating in a buffer solution the milled and sieved
samples. Dispersions with 0.2 wt % and 2.0 wt % fiber
concentrations were prepared. The buffer solution was obtained by
dissolving 40.824 grams of KH.sub.2PO.sub.4 in 2500 g of
demineralized water using a magnetic stir bar. The pH of the buffer
solution was raised to 7.0 by adding drops of 5M NaOH solution,
after which demineralized water was added to obtain a total of 3000
gram of buffer solution. Each dispersion was prepared by weighing
the appropriate amount of sample (correcting for moisture and if
applicable additive content) in 500 ml plastic pots followed by
addition of buffer solution to a total weight of 300 g. The sample
was mixed with the buffer solution by mild stirring using a spoon.
Subsequently, two different conditions were used to facilitate the
dispersion. In one series of experiments, each dispersion was mixed
with a Silverson L4RT overhead batch mixer equipped with an Emulsor
Screen (with round holes of 1 mm diameter) for 2 min at 3000 rpm.
In another series of experiments, each dispersion was treated with
the same mixer for 10 min at 8000 rpm. [0170] Measurements of G',
YS and kinematic viscosity: the measurements were perforated using
an ARG2 rheometer from TA Instruments Ltd UK equipped with
sand-blasted stainless steel parallel plates of 40 mm diameter and
operated at a temperature of 20.degree. C. using a measurement gap
of 1.000 mm. To ensure that measurements are carried out on
representative samples, the samples were gently stirred using a
teaspoon just before placing an aliquot of the sample in the
rheometer. The rheologicai analysis was carried out using a
standard protocol including a time sweep, continuous ramps (up and
down) of the shear rate and a strain sweep with the following
settings: [0171] Time sweep: delay 10 s, 5 min 0.1% strain at 1 Hz;
[0172] Continuous ramp step1; 0.1 to 500 s.sup.-1 shear rate
duration 2 min; mode; log sampling: 10 point/decade; [0173]
Continuous ramp step2: 500 to 0.1 s.sup.-1 shear rate duration 2
min; mode: log sampling: 10 point/decade; [0174] Strain sweep:
Sweep: 0.1 to 500 % Strain at 1 Hz, duration 2 min; mode: log
sampling: 10 point/decade. The data analysts software package form
TA Instruments allowed extracting the storage modulus G', the
kinematic viscosity and the yield stress (YS). G' is reported at
the time of 300 seconds. The kinematic viscosity is reported at a
shear rate of 22 s.sup.-1 (down curve). The YS is determined from
the maximum in the graph of G' versus strain %, and is defined as
YS=G'.times.strain. The characterization of the citrus fibers and
compositions of the Examples and Comparative Experiments in terms
of G', viscosity and YS, are summarised in Tables 2 and 3. [0175]
Self-suspending capacity (SSC): 100 ml of a dispersion having 0.1
wt % fibre content was prepared as presented above in the "Rheology
measurements" section. The dispersion was carefully poured to avoid
air entrapping into a 100 ml graded glass measuring cylinder while
keeping the cylinder slightly tilted. The top of the cylinder was
closed using para-film. The closed cylinder was slowly shaken by
tilting it ten times to mix and to remove any air bubbles that
might be trapped in the dispersion. The cylinder was stored at room
temperature and the fibers were allowed to settle under gravity.
After 24 hours, SSC was determined by measuring the volume occupied
by the fibers as determined by optical inspection and expressing it
as a percentage from the total volume. Values are reported in Table
1. The higher the volume, the higher and thus better the SSC of the
sample. [0176] Viscosity ratio measurements indicating the ability
of a fiber sample to develop its functionality on low shearing were
made as follows: dispersions were prepared as presented above in
the "Rheology measurements" section. A first viscosity was measured
on the dispersions following the methodology presented in the
"Rheology measurements". Subsequently, the dispersions were passed
through a homogenizer at 250 bars and allowed to rest for about 1
hour at 20.degree. C. to reach their equilibrium state. A second
viscosity was measured under the same conditions as previously
presented. The ratio of the first viscosity to the second viscosity
is used as an indicator of the sample's capacity to reach
functionality after low shear dispersion.
[0177] The invention will now be described with the help of the
following examples and comparative experiments, without being
however limited thereto.
EXAMPLE 1
[0178] Dry citrus fibers were manufactured as follows:
Step (1) Water was added to de-pectinized citrus peel (a by-product
of a pectin extraction process) to obtain an aqueous slurry having
a dry substance content of about 4 wt %. The slurry was one time
charged to a pressure homogenizer (APV homogenizer, Rannie
15-20.56) at 600 bars. An aqueous slurry containing citrus fibers
was obtained. Step (2) A precipitation tank was filled with an
aqueous isopropanol solution (about 82 wt % isopropanol in water).
The aqueous slurry containing citrus fibers was brought under
agitation into the precipitation tank by using a volumetric pump
and a precipitate in the form of granules having sizes between 5 mm
and 50 mm was formed in the tank. The slurry:isopropanol ratio was
1:2. Agitation by stirring was provided while bringing said slurry
into the tank and the precipitate was kept in the tank for about 30
minutes. Step (3) The precipitate was charged to a centrifuge
decanter (Flottweg centrifuge) operated at above 4000 rpm, to
separate the liquid phase (i.e. water and isopropanol) from the
citrus fibers. Step (4) Steps (2) and (3) were repeated and the
precipitate was subjected to an extraction step to increase the dry
substance content. The extraction step was carried out by feeding
the precipitate to a screw press. The speed and pressure of the
press were adjusted to obtain a semi-dry cake having a dry
substance content of about 22 wt %. Step (5) The semi-dry cake was
comminuted using a Lodige type FM 300 DMZ mixer, for about 15 to 30
minutes, to obtain grains having sizes in the range of 1
millimeter. Step (6) The comminuted cake was dried in a ventilated
oven at 40.degree. C. for about 2 hours to reach a moisture content
of about 8 wt %.
[0179] The properties of the obtained fibers are presented in
Tables 1 (a to e) to 3. FIG. 1 shows the T.sub.2 distribution
curves resulting from the inverse Laplace transform obtained during
NMR data analysis for the sample of Example 1 and the corresponding
matrix reference sample, respectively.
EXAMPLES 2 AND 3
[0180] Dry compositions were manufactured as follows:
Example 1 was repeated with the difference that at step (5) the
comminuted semi-dry cake was mixed with commercial sucrose in two
sucrose:fiber ratios of 0.4:1 and 7:1, respectively. Before adding
it, the commercial sucrose was milled to an average particle size
of about 250 .mu.m.
[0181] The properties of the obtained compositions are presented in
Tables 1 (a to c) to 3.
[0182] FIG. 2 shows the T.sub.2 distribution curves resulting from
the inverse Laplace transform obtained during NMR data analysis for
the sample of Example 2 and the corresponding matrix reference
sample, respectively.
COMPARATIVE EXPERIMENT 1
[0183] A dry composition was manufactured as follows:
Step (1) Water was added to de-pectinized citrus peel to obtain an
aqueous slurry having a dry substance content of about 4 wt %. The
slurry was changed to a pressure homogenizer (APV homogenizer,
Rannie 15-20.56) at 600 bars. An aqueous slurry containing citrus
fibers was obtained. Step (2) The aqueous slurry containing citrus
fibers was subjected to an extraction step with a screw press to
increase the dry substance content to a level of about 22% wt %.
Step (3) The semi-dry cake was dried on an plate in an oven at
40.degree. C. for several days to reach a moisture content of about
8 wt %.
[0184] The properties of the obtained fibers are presented in
Tables 1 (a to c) to 3.
COMPARATIVE EXPERIMENT 2 AND 3
[0185] Example 1 of U.S. Pat. No. 6,485,767 was repeated.
Commercial sucrose in two sucrose:fiber ratios of 0.1:1 and 5:1,
respectively, was used as additive and added using a paddle mixer
and mixed for 30 minutes. The sucrose had an average particles size
of about 250 (?) .mu.m.
[0186] The properties of the obtained fibers and compositions are
presented in Tables 1 (a to c) to 3. The comparative composition
having a 5:1 sucrose:fiber ratio, cannot be prepared for
measurements like the other samples due to increased stickiness and
it was discarded.
Self-Suspending Capacity, R.sub.2* and FAP Values
TABLE-US-00001 [0187] TABLE 1a SSC (%) Ex. 1 19 Ex. 2 21 Ex. 3 21
CE. 1 3 CE. 2 7 CE. 3 Not measurable
TABLE-US-00002 TABLE 1b FAP determination R.sub.2(sample) (Hz)
R.sub.2(matrix) (Hz) FAP (Hz) Ex. 1 0.79 0.41 0.37 Ex. 2 1.16 0.42
0.74
[0188] As defined in the protocol above, the FAP parameter is
determined on samples prepared and analyzed in the same way as
described for the method of measurement for R.sub.2*, with the only
difference being that during sample preparation, the mixtures
containing the inventive fibers or compositions in water were
homogenized at 1500 rpm. However, it was not possible to measure
FAP on the samples made according to the comparative experiments,
since these samples did not disperse well and/or did not stay in
dispersion long enough to allow for the measurement to take
place.
[0189] To enable the NMR characterization on the samples of
comparative experiments, R.sub.2* measurements were carried out on
samples dispersed at 3000 rpm rather than 1500 rpm. The results are
presented in Table 1c.
TABLE-US-00003 TABLE 1c R.sub.2* (HZ) dispersing at 3000 rpm Ex. 1
1.242 Ex. 2 1.23 Ex. 3 0.949 CE. 1 0.297 CE. 2 0.626 CE. 3 Not
measurable
[0190] The fact that NMR measurements were only possible after
dispersing the samples of the comparative experiments at higher
rpms (thus higher shear) may be an indication of a larger available
free-surface area for the fibers of the invention than that of
known fibers.
Rheology Measurements
[0191] Samples of the above fibers and compositions were dispersed
in water by stirring under the conditions mentioned in Tables 2 and
3 to obtain two fiber concentrations, i.e. 2 and 0.2 wt % of fibers
in water, respectively. The rheology data are presented in said
Tables 2 and 3.
[0192] It was observed that the inventive compositions have an
optimal viscoelastic stability, e.g. fewer fluctuations of
compositions' viscoelastic behavior. While the STDEV of the
inventive compositions were systematically below 50% of MAX, those
of the comparative experiments could not even be determined since
the comparative sample having 5:1 sucrose:fiber ratio was not
processable for the measurements. This is believed to demonstrate
the ability of the inventive compositions to smoothen out
viscoelastic fluctuations, which in turn may indicated a more
reliable processing thereof.
[0193] It was also observed that the inventive compositions had
greater R.sub.2* values than the known compositions which was
believed to indicate that the additive is optimally distributed
between the citrus fibers and also between the microfibrils forming
the citrus fibers. This in turn conferred to the inventive
composition unique viscoelastic properties even at concentration of
citrus fibers as low as 0.2 wt % thereby providing economy and ease
of formulation, while still providing the necessary rheological
behavior.
[0194] It was also observed that the inventive compositions had
greater Fibre Availability Parameter (FAP) values than the known
compositions which strengthened the belief that the additive is
optimally distributed between the citrus fibers and also between
the microfibrils forming the citrus fibers.
[0195] In particular it was observed that it may be possible to
readily disperse the inventive composition by applying low levels
of shear (e.g. 3000 rpm) and even lower, for short periods of time
(e.g. 2 minutes) while providing homogeneity and stability of a
wide variety of suspensions, such as those of the types used in
foods, cosmetics, pharmaceuticals, but also those used in
industrial products, such as paints and drilling muds.
[0196] From the presented data can also be observed that the fibers
and compositions made in accordance with the invention were able to
provide optimal rheological properties at extremely low
concentrations e.g. 0.2 wt %. In contrast thereof, fibers and
compositions prepared in accordance with the prior art failed to
influence the rheological behavior of dispersions containing them
at such low concentration.
[0197] Moreover, although readily dispersible at low shear levels,
the fibers and compositions of the invention were extremely
effective in providing optimum rheological properties to
dispersions containing thereof also when dispersed under increased
shear levels (e.g. 8000 rpm) for longer period of time (e.g. 10
min). Although herein called longer period of time, it is to be
noted that 10 minutes is shorter than the time used in the prior
art to disperse fibers.
[0198] Surprisingly, all of the above mentioned advantages were
achieved with substantially chemically or enzymatically unmodified
citrus fibers.
EXAMPLE 4 AND COMPARATIVE EXAMPLE 4
[0199] Ready to drink tea beverages comprising citrus fibers,
homogenized with different shear treatments were prepared using a
method according to the invention and using a comparative method,
respectively.
Citrus Fibers
[0200] For Example 4 (Ex. 4), the dry composition as described in
Example 2, comprising citrus fibers and having a sucrose content of
28.6% (w/w) was used. Herbacel AQ+ citrus fibers were used in the
comparative example (CE4).
Preparation of the Ready to Drink Milk Tea
[0201] Milk tea ingredients were combined with hot Millipore water
of 90.degree. C. as detailed in Table 4 to form 800 grains of
ready-to-drink milk tea.
TABLE-US-00004 TABLE 4 CE 4 Ex. 4 Ingredient (grams) (grams)
sucrose 51.36 51.04 creamer 14.48 14.48 Black tea powder 2.15 2.15
Herbacel AQ+ 0.86 Composition of Ex 2 1.20 Water balance
balance
[0202] The milk tea compositions were homogenized with an overhead
Silverson L4RT-A mixer equipped with a small grid, 1 mm holes head
during 5 minutes at 3000 rpm. Part of the milk tea compositions was
used to determine particle size directly after the Silverson
treatment (Ex. 4, and CE4, respectively) and another part was
homogenized in a Gea Niro Soavi Panda Plus High Pressure
Homogenizer in one pass at 250 bar (Ex 5 and CE5, respectively), as
detailed in Table 5.
TABLE-US-00005 TABLE 5 Shear treatment CE4 CE5 Ex. 4 Ex. 5
Silverson y y y y HPH 250 bar y y
Particle Size Measurement
[0203] Particle size of the ready to drink milk tea samples
(without any pretreatment such as e.g. sonication) was determined
with a Malvern Mastersizer 2000 and expressed as d(0.1), d(0.5) and
d(0.9) in table 6.
[0204] The value of d(0.5) is the diameter of the volume-equivalent
sphere corresponding to the volume-weighted median particle volume
(that is, half of the total volume of the dispersed material is
made up of particles with a volume smaller than or equal to the
median volume and half of the total volume of dispersed material
has a larger volume). Correspondingly d(0.9) is the value where 90%
of the total volume of the dispersed material is made up of
particles with volumes smaller or equal to the volume of a sphere
with this diameter and d(0.1) is the value where 10% of the total
volume of the dispersed material is made up of particles with
volumes smaller or equal to the volume of a sphere with this
diameter
TABLE-US-00006 TABLE 6 d (0.1) [.mu.m] d (0.5) ) [.mu.m] d (0.9) )
[.mu.m] CE 4 30.077 79.433 172.262 CE 5 22.531 67.250 160.153 Ex 4
0.176 23.975 87.929 Ex 5 0.106 0.327 38.141
[0205] The difference in particle size between the Examples 4 and 5
according to the invention and the Comparative Examples CE4 and CE5
indicates that the physical stability of the products comprising
the inventive composition of matter in dry form comprising citrus
fibres and sucrose is higher than that of the comparative samples
and that smaller particle sizes can be obtained with the inventive
composition, even with the application of lower amounts of shear.
Thus, these examples demonstrate that the method for preparing a
composition comprising an aqueous phase comprising dispersed citrus
fibres according the invention can be used to prepare an
oil-in-water emulsion, such as an RTD milk tea with favourable
properties, using a relatively limited amount of shear energy
during product manufacture.
EXAMPLES 6 AND 7 AND COMPARATIVE EXAMPLES 6 and 7
[0206] Hand dishwash (HDW) surfactant formulations structured with
different citrus fibre preparations were compared and investigated
in terms of their rheological properties. Example 6 was structured
with the dry citrus fibres of Example 1 above. Example 7 was
structured with the composition of matter in dry form of Example 2
above, which contained 28.6% sucrose. Comparative example CE6
comprised non-defibrillated citrus fibre (Herbacel AQ+ type N,
Herbafood, Germany). Comparative Example CE7 was prepared with
Herbacel AQ+ type N citrus fibre material that was defibrillated
using a high pressure homogeniser (Panda NS1001L, Niro-Soavi,
Parma, Italy) operated at 200 bar. The preparation of the samples
is discussed below. The formulations of the Example compositions 6,
7, CE6, and CE7 are provided in Table 7.
[0207] The rheology of the samples was analysed with a controlled
stress rheometer (TA-AR 2000ex, TA instruments, Delaware, US)
fitted with a sandblasted plate geometry (sandblasted plate
diameter 40 mm, gap 1.5 mm) to obtain viscoelastic moduli (G') by a
time sweep oscillation of 5 min at 20.degree. C. with a strain of
0.1% and frequency of 1 Hz.
[0208] In addition, the ability to suspend particulates was
investigated by stirring 1 wt % olive stone abrasive (16-30 mesh)
into aliquots of each of the 4 samples, transferring these in 4
measured cylinders, and performing an accelerated stability test by
storage of the samples in a temperature regulated cabinet at
45.degree. C. At days 0, 3, and 5 the volume of the sedimented
particles was recorded and expressed as % sediment by comparison to
the total product volume. Results are presented in Table 9.
Preparation of Samples
[0209] The hand dish wash compositions were made following the
below preparation instructions: [0210] 1Add demi-water in a beaker.
[0211] 2Add an equivalent of 0.25 wt % of citrus fibre material and
hydrate with overhead paddle stirrer for 20 minutes (model RW27,
IKA-Werke, Germany). [0212] 3. Add NaOH while mixing. [0213] 4. Add
LAS acid while mixing. [0214] 5. Add SLES and mix until dissolved.
[0215] 6. Add preservative while mixing. [0216] 7. Adjust pH
between 6-7 using NaOH or citric acid. [0217] 8. For Examples 6 and
7, and comparative example CE6: Shear the whole formulation by
single passage through an in-line Silverson at 8000 rpm using a
flow of 300 ml/min. [0218] 9. For Comparative Example CE7: Shear
the whole formulation by single passage through a high pressure
homogeniser at 200 bar. [0219] 10. Add MgSO4.7H2O and mix until
dissolved.
TABLE-US-00007 [0219] TABLE 7 Formulations of Ex 6, Ex7, CE6, and
CE7. Ex 6 Ex 7 CE7, CE8 Ingredients (% wt) (% wt) (% wt)
Demineralised water 76.98 76.88 76.98 Citrus Fibre of Ex. 1 0.25 --
-- Citrus Fibre preparation of Ex. 2 -- 0.35 -- Herbacel AQ+ type N
-- -- 0.25 NaOH (50%) 3.23 3.23 3.23 LAS acid (97%) 11.60 11.60
11.60 SLES 1EO (70%) 5.36 5.36 5.36 Nipacide BIT 20 preservative
0.08 0.08 0.08 MgSO4.cndot.7H2O 2.50 2.50 2.50 Total 100.00 100.00
100.00
[0220] The results of the rheological measurements in Table 8 show
that the HDW product of CE7, structured with reference material
Herbacel AQ+ as treated above resulted in the lowest G' and yield
stress values.
[0221] The use of pre-defibrillated citrus fibre material of Ex. 7
in a HDW formulation and further activation by an in-line Silverson
mixer, significantly improved G' and yield stress of the HDW
product.
[0222] The highest G' and yield stress value was obtained for the
HDW product of Ex 7, structured with the citrus fibre preparation
of Ex. 2. Stabilising the pre-defibrillated primary cell wall
material used in Ex 7 with sucrose clearly further enhanced its
structuring ability upon low shear activation.
[0223] Comparison shows that Example 6 exhibited a similar G' value
as CE 7. However, Ex. 6 did not require high pressure
homogenisation at 200 bar as CE7 did.
TABLE-US-00008 TABLE 8 G' (viscoelastic modulus) and yield stress
of HDW products structured with citrus fibre material G' (Pa),
Yield stress (Pa), n = 2 SD* n = 2 SD* CE 6 1.34 .+-.0.01 0.03
.+-.0.023 Ex 6 5.64 .+-.0.08 0.13 .+-.0.001 Ex 7 9.19 .+-.0.23 0.24
.+-.0.004 CE 7 5.53 .+-.0.51 0.06 .+-.0.012 *SD = standard
deviation
[0224] The accelerated suspension results of olive stones in the
HDW products in Table 9 show that the suspending ability of the
various samples followed the rheological behaviour of these samples
as outlined in Table 8. The higher the G' and yield stress of the
sample, the better its olive stone suspending properties. Ex. 7
provided the best suspension results.
TABLE-US-00009 TABLE 9 Accelerated suspension test at 45.degree. C.
of HDW products structured with citrus fibre material holding 1 wt
% olive stone abrasive particles Olive stone suspending ability of
HDW products (ml .+-. SD) day 0 day 3 day 5 day 15 CE 6 100 3.5
.+-. 0.7 3.0 .+-. 0.9 2.7 .+-. 0.5 Ex 6 100 89.4 .+-. 0.2 81.2 .+-.
2.6 68.2 .+-. 2.1 Ex 7 100 97.0 .+-. 0.1 89.1 .+-. 1.6 75.5 .+-.
0.1 CE 7 100 82.6 .+-. 3.2 73.1 .+-. 0.2 60.3 .+-. 0.9
[0225] In conclusion, it was shown that citrus fibre material of
the present invention only requires low shear activation to achieve
similar or even superior product structure, whereas products
structured with traditional citrus fibre--processed in the some
way, or at higher shear activation--showed inferior structure.
TABLE-US-00010 TABLE 2 Rheology 1 Rheology 2 (2 minutes at 3000
rpm) (10 minutes at 8000 rpm) Drying Moisture Sample Fiber .eta. at
.eta. at time Content weight conc. .sigma.(.dagger-dbl.) %
22.sup.-1 .sigma.(.dagger-dbl.) % 22.sup.-1 Sucrose:Fiber (o) (*)
(**) (***) G' of of YS sec G' of of YS sec ratio (min) (%) (%) (Pa)
G' MAX (PA) (Pa s) (Pa) G' MAX (PA) (Pa s) Ex.1 0:1 120 8 229 2 172
108 29 2.3 0.74 484.6 91 15 10.6 2.26 Ex.2 0.4:1 120 290
367(.dagger.) 5.0 1.47 604.7(.dagger.) 14.3 2.74 Ex.3 7:1 180 1279
191 3.1 0.82 426.8 8.8 1.85 CE.1 0:1 1440 214 0.11 -- -- 0.04 0.004
17.95 -- -- 0.2 0.10 CE.2 0.4:1 1440 314 2.59 0.4 0.02 155.7 1.5
0.60 CE.3 5:1 4320 1256 N/M N/M N/M N/M N/M N/M (o) = drying time
to reach the mentioned moisture content. (*) = moisture content of
the dry composition. (**) = sample's weight, i.e. the weight of the
dispersed dry composition in water, used for rheological
measurements. (***) = citrus fiber's concentration in the dispersed
composition in water. (.dagger.) = MAX (.dagger-dbl.) = STDEV N/M =
not measurable indicates data missing or illegible when filed
TABLE-US-00011 TABLE 3 Rheology 1 Rheology 2 (2 minutes at 3000
rpm) (10 minutes at 8000 rpm) Drying Moisture Sample Fiber .eta. at
.eta. at time Content weight conc. .sigma.(.dagger-dbl.) %
22.sup.-1 .sigma.(.dagger-dbl.) % 22.sup.-1 Sucrose:Fiber (o) (*)
(**) (***) G' of of YS sec G' of of YS sec ratio (min) (%) (%) (Pa)
G' MAX (mPA) (mPa s) (Pa) G' MAX (mPA) (mPa s) Ex.1 0:1 120 8 229
0.2 0.14 0.03 16 28 4.6 2.867 1.05 27 208 27.1 Ex.2 0.4:1 120 290
0.17 56 7.9 3.903(.dagger.) 248 32.8 Ex.3 7:1 180 1279
0.20(.dagger.) 40 5.1 1.809 241 22.3 CE.1 0:1 1440 214 0.01 -- --
N/M 1.9 0.068 -- -- 10 2.8 CE.2 0.4:1 1440 314 0.07 N/M 2.3 0.0924
10 6.0 CE.3 5:1 4320 1256 N/M N/M N/M N/M N/M N/M (o) = drying time
to reach the moisture content of 8%. (*) = moisture content of the
dry composition. (**) = sample's weight, i.e. the weight of the
dispersed dry composition in water, used for rheological
measurements. (***) = citrus fiber concentration in the dispersed
composition in water. (.dagger.) = MAX (.dagger-dbl.) = STDEV N/M =
not measurable indicates data missing or illegible when filed
* * * * *