U.S. patent application number 12/548127 was filed with the patent office on 2009-12-17 for natural sweetener and methods of manufacturing thereof.
This patent application is currently assigned to KRAFT FOODS GLOBAL BRANDS LLC. Invention is credited to George William Haas, Orlando Herrera-Gomez, Nam-Cheol Kim, Dominic Vellucci, Leslie George West.
Application Number | 20090311404 12/548127 |
Document ID | / |
Family ID | 40578782 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090311404 |
Kind Code |
A1 |
West; Leslie George ; et
al. |
December 17, 2009 |
Natural Sweetener And Methods Of Manufacturing Thereof
Abstract
A method of preparing a natural sweetener from a heat-processed
powdered fruit extract of the cucurbitaceae family, such as luo han
guo is provided. In one embodiment, the method provides a cleaner
tasting and concentrated natural sweetener in which objectionable
flavors, odors, colors, and insoluble components are removed to
form the natural sweetener.
Inventors: |
West; Leslie George;
(Winnetka, IL) ; Vellucci; Dominic; (Eastchester,
NY) ; Kim; Nam-Cheol; (Deerfield, IL) ; Haas;
George William; (Mount Prospect, IL) ; Herrera-Gomez;
Orlando; (Evanston, IL) |
Correspondence
Address: |
FITCH EVEN TABIN & FLANNERY
120 SOUTH LASALLE STREET, SUITE 1600
CHICAGO
IL
60603-3406
US
|
Assignee: |
KRAFT FOODS GLOBAL BRANDS
LLC
Northfield
IL
|
Family ID: |
40578782 |
Appl. No.: |
12/548127 |
Filed: |
August 26, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12025316 |
Feb 4, 2008 |
|
|
|
12548127 |
|
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Current U.S.
Class: |
426/548 |
Current CPC
Class: |
A23G 3/36 20130101; A23V
2002/00 20130101; A23V 2200/132 20130101; A23L 5/273 20160801; A23L
27/36 20160801; A23V 2002/00 20130101 |
Class at
Publication: |
426/548 |
International
Class: |
A23L 1/236 20060101
A23L001/236 |
Claims
1. A natural sweetener obtained from a heat-processed extract from
a fruit of the cucurbitaceae family, the natural sweetener
comprising: at least about 30 percent mogroside V on a dry basis as
determined using HPLC; less than about 10 mg/gram of undesired
color and taste defining components; less than about 50 ppm of
undesired flavor and odor volatile defining components; and about
0.5 percent or less of undesired water-insoluble components.
2. The natural sweetener of claim 1, wherein the undesired flavor
and odor volatile defining components include at least one of
saturated aldehydes, unsaturated aldehydes, methyl ketones, butyl
crotonate, and combinations thereof.
3. The natural sweetener of claim 1, wherein the undesired flavor
and odor volatile defining components include about 10 ppm or less
saturated aldehydes, about 0.6 ppm or less unsaturated aldehydes,
about 0.5 ppm or less methyl ketones, and about 4 ppm or less
butyl-crotonate.
4. The natural sweetener of claim 1, wherein the undesired flavor
and odor volatile defining components include about 0.5 ppm or less
hexanal; about 1 ppm or less heptanal; about 1.5 ppm or less
octanal; about 7 ppm or less nonanal; about 0.5 ppm or less
decanal; about 0.1 ppm or less octenal; about 0.3 ppm or less
undecenal; about 0.1 ppm or less 1-decanienal; about 0.1 ppm or
less 2-decadienal; about 0.5 ppm or less 2-heptanone; about 0.1 ppm
or less 2-undecanone; and about 3.8 ppm or less
butyl-crotonate.
5. The natural sweetener of claim 1, wherein the undesired color
and taste defining components include at least phenolic
compounds.
6. The natural sweetener of claim 5, wherein the undesired color
and taste defining components include about 4 mg/gram or less
phenolic compounds.
7. The natural sweetener of claim 1, wherein the mogroside V is
provided from a heat processed luo han guo extract.
8. The natural sweetener of claim 1, wherein the natural sweetener
is a powder with a moisture content of about 7 percent or less.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of prior application Ser.
No. 12/025,316, filed Feb. 4, 2008, which is hereby incorporated
herein by reference in its entirety.
FIELD
[0002] The field relates to methods of preparing a natural
sweetener from a fruit of the cucurbitaceae family and, in
particular, methods of preparing a natural sweetener from a
heat-processed, powdered luo han guo extract.
BACKGROUND
[0003] Luo han guo generally refers to a fruit of Siraitia
grosvenori, which is a member of the Cucurbitaceae family, a
perennial vine native to certain regions of southern Asia and
China. The luo han guo fruit is generally known for its intensely
sweet taste, and extracts of the fruit can be up to about 300 times
sweeter than sugar. It is believed that the sweetness of luo han
guo comes primarily from mogrosides, which are a group of terpene
glycosides, generally comprising only about 1 percent of the fleshy
part of the luo han guo fruit. It is generally understood that the
majority of the sweetness is provided by one particular mogroside,
which is commonly labeled mogroside V.
[0004] Luo han guo is most commonly available in a powdered extract
form, which is reported to have at least about 80 percent
mogrosides on a dry basis using a spectrophotometric analysis
(generally about 18 to about 23 percent mogroside V on a dry basis
using high a performance liquid chromatography (HPLC) analysis).
Such extracts are prepared through a process that attempts to
remove undesirable organoleptic components. However, the drying
process commonly used to preserve the fruit before preparing
commercial powders can impart other undesirable colors, flavors,
and odors to the extract. As a result, commercially available luo
han guo powdered extracts generally cannot be used as a sweetener
in foods and beverages unless masking and/or other components are
also used to hide the objectionable organoleptic properties.
[0005] Commercially available luo han guo fruit also may be
subjected to rigorous heat processing or heat treatment to
inactivate any viable cells. It is believed that this heat
treatment alters the chemistry of the fruit components in the
extract. For example, heat processed fruit extracts are often
darker in color, exhibit more off-odors, and more off-flavors than
non-heat processed fruit extracts. Therefore, while heat processed
luo han guo fruit extract may be more readily available as a raw
material source, it has the shortcoming that it possesses
additional undesired organoleptic characteristics (i.e., flavors,
odors, tastes, and colors) as a result of the heat processing that
limits its use as a traditional sweetener in foods and beverages.
When used as such a sweetener, masking components are also
typically needed to hide the undesired organoleptic properties of
the heat-processed extract.
[0006] Methods of processing fresh luo han guo fruit, rather than
the more readily available heat-processed powdered fruit extracts,
to attempt removal of undesirable components have been proposed
(see, for example, U.S. Pat. No. 4,084,010; U.S. Pat. No.
5,411,755; U.S. Pat. No. 5,433,965; U.S. Pat. No. 6,124,442, U.S.
Pat. No. 6,461,659 B1; and U.S. Pat. No. 6,682,766 B2 as well as
Patent Application Publication Number US 2006/0003053 A1; and EP 0
684 771 B1). However, fresh luo han guo is difficult to obtain
(largely due to export restrictions) and also difficult to store
either as fresh fruit or juice obtained from the fresh fruit
because it tends to degrade over time. Luo han guo juice has a pH
of about 6, and contains sugars that can brown and pectin that can
gel upon storage. As a result, the processing methods for fresh luo
han guo fruit have limited applicability to those not able to
obtain and use such fresh fruit within a short time frame.
Moreover, as shown in the Examples, natural sweeteners prepared
using such fresh-fruit processing methods still exhibit
objectionable organoleptic characteristics.
[0007] In addition to requiring raw materials difficult to obtain,
the existing methods of treating fresh fruit also generally use
cation exchange resins (strong and weak acid exchange resins) that
typically remove sulfur-containing amino acids and soluble protein
precursors. Strong and weak acid cation exchange resins, however,
also have a tendency to bind with mogrosides and remove them from
the solution being treated. Therefore, the use of such cation
exchange resins to treat mogroside solutions may need to be closely
monitored and/or limited in duration so that removal of the desired
mogroside molecules is minimized. Such shortcoming adds complexity
to the process and generally limits the duration that cation ion
exchange can be used for processing. The conventional use of cation
exchange resins, therefore, often balances a tradeoff between
sufficient resin exchange time to remove unwanted substances and
the retention of high levels of mogrosides.
[0008] Alternatively, if the cation exchange resins bind and remove
large quantities of mogrosides, the resins can be washed using
various wash solutions or solvents to release the mogrosides from
the resin (See, e.g., CN 1907091 A). Such additional washing steps,
however, can add extra expense, time, and processing to the
manufacturing process and, therefore, are generally not desired.
Moreover, with the use of cation exchange resins that tend to bind
with the mogrosides and the subsequent use of wash solvents, the
mogrosides have interacted chemically and/or physically with a
non-natural component during manufacturing and may be less desired
in some cases as a fully natural sweetener due to this
interaction.
SUMMARY
[0009] Methods are provided of forming a natural sweetener from a
processed extract obtained from the fruit of cucurbitaceae family,
such as luo han guo. The methods herein use heat processed fruit
extracts, usually in powdered form, rather than fresh luo han guo
used in conventional processing methods. As described below, the
methods herein further process the powder to remove objectionable
organoleptic properties, such as off-flavors, odors, tastes, and/or
colors as well as undesired insoluble components that tend to be
present in the starting extracts as a result of its prior
processing. In one embodiment, the methods use treatment steps that
reduce and, preferably, eliminate the interaction of non-natural
components (i.e., resins, solvents, etc.) with the desired
mogrosides so that the resultant sweetener can be formed with
minimal chemical and/or physical interaction of the desired
mogrosides with non-natural components.
[0010] In one form, the resultant sweetener composition is a
cleaner tasting and concentrated mogroside powder that is generally
suitable for use as a natural sweetener in comestibles (such as
beverages, desserts, confections and the like), pharmaceuticals,
supplements, and other products requiring a high intensity, natural
sweetener. The resultant mogroside powder can generally be used
without the necessity of adding other agents to cover or mask off
flavors, odors, or other defects in the starting extract material
because sufficient amounts of the undesired components that cause
such defects have been removed from the sweetener.
[0011] In one aspect, preferred starting materials for the methods
herein are heat processed fruit extracts of luo han guo having at
least about 18 to about 23 percent mogroside V on a dry basis as
measured by HPLC. Total mogrosides in such heat-processed extracts
can be reported as up to about 80 percent as determined by
spectrophotometric methods. As used herein, mogroside content will
be reported as mogroside V using an HPLC analysis rather than a
spectrophotometric analysis. The initial mogroside content,
however, may vary depending on the particular raw materials
used.
[0012] As discussed previously, commercially available heat
processed fruit extracts, such as the luo han guo extracts, also
include undesired flavor and odor volatile defining components,
undesired taste and color defining components, and undesired
water-insoluble components that generally render the heat processed
extract undesirable for further use as a typical sweetener in foods
and beverages. The processes herein remove sufficient amounts of
these undesirable components to render the extract suitable for use
as a sweetener generally without the need to mask any undesirable
organoleptic properties.
[0013] In one embodiment, the method first prepares an aqueous
suspension or slurry of the heat processed extract from a fruit of
the cucurbitaceae family, such as the luo han guo fruit. Then, the
method provides for removal of at least a portion of the undesired
water-insoluble components from the aqueous suspension to form a
clarified aqueous solution. Next, the clarified aqueous solution is
subjected to an ion exchange resin, preferably an anion exchange
resin, to form a treated aqueous solution that generally removes at
least a portion of the undesired color and taste defining
components and many of the undesired off flavor and odor defining
components. Lastly, the treated aqueous solution is concentrated
and further clarified to remove additional off flavors, odors, and
colors. Since the anion exchange resins generally do not interact
with the mogrosides chemically or physically and the mogrosides are
generally water soluble, the mogrosides simply pass through the
process and are recovered in the final product.
[0014] In one embodiment, the resultant material, which may be
dried into a powdered form with a moisture content of about 7
percent or less, is a cleaner tasting and concentrated natural
sweetener (relative to unmodified heat-processed and fresh-fruit
derived luo han guo sweeteners) including greater than about 30
percent and, preferably, greater than about 40 percent mogroside V
on a dry basis (HPLC). In one form, the resultant natural sweetener
also includes less than about 50 ppm (preferably about 15 ppm or
less) of undesired flavor and odor volatile defining components,
less than about 10 mg/gram (preferably about 4 mg/gram or less) of
undesired color and taste defining components, and about 0.5
percent or less (preferably about 0.1 percent or less) of
undesirable water-insoluble components. Of course, such composition
may vary depending on the starting materials, processing
conditions, and desired final product characteristics. Such
resulting material may be used as a natural sweetener and generally
does not impart any off organoleptic notes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a flowchart of an exemplary method to prepare a
fruit extract from the cucurbitaceae family.
DETAILED DESCRIPTION
[0016] Methods are provided of forming a natural sweetener from a
fruit extract of the cucurbitaceae family where the natural
sweetener has a high level of sweet components and a low or
insignificant level of components that provide objectionable
organoleptic characteristics. The methods are particularly suited
to treat heat processed, powdered fruit extracts from the luo han
guo fruit, but the methods herein are also suitable to process
other sweet fruit extracts, other fruits from the cucurbitaceae
family, and other sweet extracts containing triterpene glycosides,
mogrosides, and the like. In one embodiment, the methods treat a
heat processed or heat treated luo han guo extract to remove
sufficient amounts of components that exhibit objectionable
organoleptic properties, such as insoluble components and
components that exhibit off-flavors, off-odors, off-colors, and
off-tastes that may be inherent in the fruit or extract, and/or
most likely tend to be formed in the extract due to the prior
processing methods. The resultant material is suitable for use as a
natural sweetener in comestibles (such as beverages, desserts,
confections to suggest but a few examples), pharmaceuticals,
supplements, and other products requiring a high intensity, natural
sweetener.
[0017] Referring to FIG. 1, one embodiment of a method 10 to
prepare a natural sweetener from a heat processed luo han guo
extract 11 is generally illustrated. In this embodiment, the method
first prepares an aqueous slurry or suspension 12 of the heat
processed fruit extract 11. Next, at least a portion (at least
about 90 percent, preferably at least about 97 percent, and most
preferably at least about 99 percent) of any undesired
water-insoluble components are removed from the aqueous suspension
12 to form a clarified aqueous solution 14. The clarified aqueous
solution 14 is then subjected to an ion exchange resin, preferably
an anion exchange resin, to form a treated aqueous solution 16. The
ion exchange resin is effective to generally remove significant
amounts of the undesired taste and color defining components as
well as many off flavors and off odors, while at the same time
minimizing and, preferably, eliminating any interaction between the
desired mogrosides and the resin. In addition, with the use of an
anion exchange resin, the methods herein generally avoid a resin
washing step to free bound mogrosides from the resin because the
resin generally does not significantly interact with the
mogrosides. Lastly, the treated aqueous solution is concentrated
and further processed using microfiltration-type technology 18 to
concentrate and remove additional off flavor, off odor, and off
color components to form the natural sweetener 20. With the
mogrosides being largely water soluble and the use of the anion
exchange resins that do not bind or interact with the mogrosides,
the desired mogrosides simply pass through the process into the
recovered solution.
[0018] The resultant sweetener, which may be dried into a powdered
form, is a cleaner tasting and concentrated natural sweetener (as
compared to unmodified heat-processed and fresh-fruit derived luo
han guo sweeteners) that generally does not impart any significant
off-organoleptic notes. Preferably, the resultant material is dried
to obtain a powdered form, but the filtered and concentrated
material may also be used as an aqueous solution. Other uses and
forms of the resultant material are also possible.
[0019] A preferred starting material is a heat processed fruit
extract of luo han guo, which preferably includes at least about 18
percent and, more preferably, at least about 23 percent total
mogroside V on a dry basis (HPLC). Suitable starting materials
include, for example, Mormordica 80% (Amax NutraSource, Inc.,
California) and PureLo (BioVittoria, New Zealand) to suggest but a
few sources. Other sources are, of course, also suitable for use in
the methods herein. Such extracts are available in powdered,
liquid, and concentrated forms. By one approach, preferred extracts
are a powdered material with about 5 percent or less moisture and,
preferably, about 4 percent or less moisture. In some forms, the
powdered extracts are also capable of being processed through an 80
mesh screen, but such granulation size is not a requirement as
other sizes are also appropriate for the methods herein. It will be
appreciated that the compositions, form, and other characteristics
of the starting material can vary depending on the source,
composition, and other processing parameters used to form the
starting material.
[0020] While not intending to be limited by theory, it is believed
that the desired sweet component in the extract is supplied from
mogroside V. This component has the general chemical formula (A)
shown below where R and R' are various glucose residues. These
mogrosides generally have average molecular weights ranging from
about 1,100 to about 1,500 Dalton (and preferably about 1,100 to
about 1,300 Dalton), and tend to be very soluble in water. In one
form, mogroside V has an average molecular weight of about 1,287
Dalton. The methods herein remove significant amounts of the
undesirable components from the extract while maintaining high
levels of this desired mogroside component. In one aspect, removal
of significant amounts of undesired components includes the removal
of an amount of the undesired components sufficient to provide the
desired sweetness and organoleptic properties in a food or beverage
without the need for masking agents. In addition, the methods
herein process and concentrate the mogroside composition with
minimal and, preferably, no interaction of the mogrosides with
non-natural components, such as ion exchange resins and/or wash
solvents.
##STR00001##
[0021] As discussed in the background, commercially available luo
han guo fruit is often subjected to rigorous heat processing or
treatment to inactivate any enzymes and viable cells. It is
believed that such heat processing alters the chemistry of the
fruit and, therefore, extracts prepared from the fruit, generally
resulting in additional off flavors, off-odors, intense and
unexpected colors, undesirable tastes, and/or the presence of
insoluble materials that can provide unexpected and undesired
mouthfeel and other properties when used as a sweetener in food and
beverage unless significant amounts of masking or other agents are
included. As a result, while the commercially available heat
processed fruit extracts are generally easier to obtain and store
(relative to fresh luo han guo) because they are more readily
available and generally not subject to the stability issues of
fresh fruit, the heat processed fruit extracts can be difficult to
use as a typical sweetener due to colors, flavors, odors, and taste
components that are generally not accepted by many consumers.
[0022] For example, unmodified, heat processed fruit extracts (the
starting materials for the methods herein) can contain quantities
of undesired flavor and odor volatile defining components (such as
aldehydes, unsaturated aldehydes, methyl ketones, butyl crotonate,
and the like), significant amounts of undesired color and taste
defining components (such as phenolics and the like) and
significant amounts of undesired water-insoluble components. These
components can provide strong flavors, intense colors, strong
odors, and/or other undesirable organoleptic properties to the
extract that are generally not expected or desired in a
sweetener.
[0023] In some cases, for example, it has been determined that
unmodified, commercially available heat processed luo han guo
extracts can include up to about 80 ppm undesired flavor and odor
volatile defining components, up to about 60 mg/gram of undesired
color and taste defining components, and up to about 4 percent
undesired insoluble components. In particular, unmodified,
commercially available heat processed luo han guo extracts can
include between about 1 and about 45 ppm aldehydes (i.e., hexanal,
heptanal, octanal, nonanal, decanal, and the like), up to about 2
ppm unsaturated aldehydes (i.e., octenal, undecenal, 1-decadienal,
2 decadienal, and the like), up to about 3 ppm methyl ketones
(i.e., 2-heptanone, 2 undecanone, and the like), up to about 31 ppm
butyl-crotonate, up to about 60 mg/gram phenolics, and up to about
4 percent insoluble components. Of course, the above ranges can
vary depending on the composition, source, and other
characteristics of the fruit. While not intended to be limited by
theory, it is believed that aldehydes can impart strong grassy/hay
like and/or ashy/smoky flavor notes and can be linked to lipid
oxidation; unsaturated aldehydes can provide stale and fatty notes;
methyl ketones can provide fruity and/or blue cheese flavors and
odors; and butyl-crotonate can provide fruity flavors. All of these
flavors and odors are generally undesired in a sweetener because
they impart unexpected tastes and smells to comestibles when used
in place of traditional sweeteners.
[0024] In one embodiment, the method first prepares an aqueous
suspension or slurry of the powdered heat processed fruit extract.
Generally, the suspension has about 2 to about 15 percent solids,
preferably, about 9 to about 11 percent solids, and most preferably
about 10 percent solids. The slurry may be prepared by adding the
appropriate amount of powdered extract to an amount of water and
suspending the powder to form a uniform slurry. By one approach,
mixing of about 30 minutes is sufficient to form such a uniform
slurry. The slurry generally includes water soluble components and
water-insoluble components.
[0025] Next, at least a portion of any undesired water insoluble
components are removed from the slurry. By one approach, at least
about 90 percent, preferably about 97 percent, and most preferably
at least about 99 percent of the undesired water-insoluble
components are removed from the aqueous slurry to form a clarified
filtrate or a clarified aqueous solution. It is believed these
undesired water-insoluble components include macromolecules (such
as polysaccharides, proteins, and the like) or other poorly soluble
molecules. By one approach, the undesired water insoluble
components are removed using simple filtration, vacuum filtration,
membrane filtration, filtration aids, centrifugation, decanting, or
various combinations thereof. Possible filtration aids include
fiber, wool, diatomaceous earth, charcoal, and mixtures thereof. In
one aspect of the filtration, this removal step can be accomplished
between about 32.degree. F. and about 212.degree. F. and at both
sub-atmospheric and atmospheric pressures. Preferably, the
undesired water insoluble components are removed using vacuum
filtration to form the clarified filtrate or clarified aqueous
solution. As the mogrosides are soluble in water, they generally
pass through the filter into the clarified filtrate or clarified
aqueous solution.
[0026] Next, the clarified aqueous solution is subjected to an
anion exchange resin to form a treated aqueous solution. The anion
exchange resin is effective to generally remove sufficient amounts
of the undesired color and taste defining components and many of
the undesired flavor and odor volatile defining components, but the
resin preferably does not interact in any significant amount with
the desired mogroside content. By one approach, the anion exchange
resin removes sufficient amounts of the undesired color and taste
defining components, such as sufficient amounts of phenolic
components, generally without substantially interacting with or
binding with the mogroside components. Preferably, the anion
exchange resin removes at least about 50 percent, and more
preferably, at least about 94 percent of the undesired color and
taste defining components (i.e., phenolic components and the like)
and portions of the undesired flavor and odor defining components
from the clarified aqueous solution to form the treated aqueous
solution. Because the resin generally does not bind or interact
with the mogroside components, they simply pass through the resin
column and the treated aqueous solution contains the desired
mogroside V components.
[0027] In one aspect, the anion exchange resin is preferably a food
grade adsorbent anion exchange resin, such as strong base or weak
base anion exchange resins. Suitable resins are Amberlite.TM.
series resins (Rohm and Haas, Philadelphia, Pa.); however, other
anion exchange resins are also suitable depending on the particular
application so long as the resin has minimal and, preferably, no
interaction with the mogrosides and is effective to remove
sufficient amounts of the undesired color and taste defining
components.
[0028] As discussed in the Background, existing processing methods
commonly use cation exchange resins that have been discovered to
possess only a limited ability to remove undesired color and taste
defining components, such as phenolic and the like compounds. In
particular, phenolic compounds are anionic and, therefore, will
typically not be removed using the prior methods with cation
exchange resins. Therefore, the existing processing methods
discussed in the Background would not sufficiently remove the
undesired color and taste defining components from heat processed
luo han guo extracts.
[0029] The methods herein, on the other hand, form the treated
aqueous solution after exposure with the anion exchange resin that
includes most, if not substantially all, of the mogroside
components that were originally present in the initial aqueous
slurry (it is expected that at least about 90 percent or greater
and, preferably, about 90 to about 100 percent of the mogroside V
will be recovered). Because the ion exchange resins are anionic,
they generally will not interact or bind with the mogrosides so
that the mogrosides simply pass through the ion exchange columns
without interacting with the resins therein. Use of such resins is
advantageous because it eliminates the need to wash the resin
column to remove any bound mogrosides or the need to carefully
monitor the contact time of the solution with the resin to minimize
removal of the mogrosides. The clarified aqueous solution may be in
contact with the anionic resin for a sufficient time to remove the
undesired color and taste components and other undesired materials
to desired levels.
[0030] Lastly, the treated aqueous solution is concentrated and
further processed to remove additional undesired off flavors, off
odors, and off colors. In one embodiment, such concentration and
additional processing is completed by removing water and undesired
water soluble components less than about 1,000 Dalton and,
preferably, less than about 500 Dalton using, for example,
ultrafiltration, nanofiltration, diafiltration, microfiltration,
reverse osmosis, and the like, or combinations thereof. By one
approach, such water-soluble components are removed using an
ultrafiltration membrane between 32.degree. F. to about 212.degree.
F. For example, a suitable membrane is a 1,000 Dalton MWCO
polyethersulfone membrane (Pall Corporation) operated at room
temperature (i.e., about 75.degree. F.) and about 50 psig; however,
other types of membranes and operating conditions appropriate for
such membranes may also be used. Preferably, any size membrane can
be used so long as it generally does not remove significant amounts
of the desired mogrosides.
[0031] Evaporation may also be used together with or instead of the
microfiltration-type membranes to concentrate the treated aqueous
solution. However, evaporation by itself (without microfiltration
type processing) generally forms a less desirable product that
still exhibits some off-notes. While not intending to be limited by
theory, in addition to concentrating the solution, it is believed
that the microfiltration-type membranes further improves the
clarified aqueous solutions by removing additional undesired
water-soluble, flavor, color, and/or odor active components that
are not removed when using only evaporation.
[0032] The resultant aqueous solution is a cleaner tasting and
concentrated natural sweetener (relative to unmodified
heat-processed and fresh-fruit derived luo han guo sweeteners),
which is formed out of a heat processed luo han guo extract, that
generally does not impart any off organoleptic notes. The resultant
material is a solution having about 10 to about 30 percent solids
(generally, higher solids preferred). By one approach, the
resultant solution is dried using spray-drying, freeze drying,
drain-drying, or the like techniques to form a powdered sweetener
having a moisture content of about 7 percent or less.
[0033] In one example of the method, the resultant material (as
compared to the starting heat processed extract) has at least about
97 percent and, preferably, at least about 99 percent of the
undesired water insoluble components removed; at least about 60
percent and, preferably, at least about 81 percent of the undesired
flavor and odor volatile defining compounds removed; and at least
about 50 percent and, preferably, at least about 95 percent of the
undesired color and taste defining components removed. For purposes
herein, the undesired flavor and odor volatile defining components
shall include at least aldehydes, methyl ketones, butyl crotonate,
and similar compounds. The undesired color and taste defining
components shall include at least phenolic and similar
compounds.
[0034] In another example, compared to the starting heat processed
fruit extract, the resultant product has at least about 45 percent
less aldehydes (preferably about 45 to about 81 percent less
aldehydes), at least about 50 percent less unsaturated aldehydes
(preferably about 50 to about 84 percent less unsaturated
aldehydes), at least about 50 percent less methyl ketones
(preferably about 50 to about 83 percent less methyl ketones), at
least about 50 percent less butyl-crotonate (preferably about 50 to
about 88 percent less butyl-crotonate), and at least about 50
percent less phenolic components (preferably about 50 to about 95
percent less phenolic components). At the same time, the resultant
material preferably includes at least about 30 percent and,
preferably, at least about 40 percent mogroside V on a dry basis
(HPLC). Of course, the above results are only but one example of
processing luo han guo extracts by the methods described herein. It
will be appreciated that these results may vary depending on the
composition of the starting material, process conditions, and other
factors.
[0035] In another example, after subjecting the extract to the
methods herein, the resultant material also preferably has less
than about 10 mg/gram and, preferably, less than about 4 mg/gram of
the undesired color and taste defining components; less than about
50 ppm and, preferably, about 15 ppm or less of the undesired
flavor and odor volatile defining components; and about 0.5 percent
or less and, preferably, about 0.1 percent or less of the undesired
water-insoluble components. In yet another example, the resulting
product preferably contains about 10 ppm or less aldehydes, about
0.6 ppm or less unsaturated aldehydes, about 0.5 ppm or less methyl
ketones, and about 4 ppm or less butyl-crotonate. More
specifically, the resultant material preferably includes about 0.5
ppm or less hexanal, about 1 ppm or less heptanal, about 1.5 ppm or
less octanal, about 7 ppm or less nonanal, about 0.5 ppm or less
decanal, about 0.1 ppm or less octenal, about 0.3 ppm or less
undecenal, about 0.1 ppm or less 1 decanienal, about 0.1 ppm or
less 2 decadienal, about 0.5 ppm or less 2 heptanone, about 0.1 ppm
or less 2 undecanone; and about 3.8 ppm or less butyl-crotonate. Of
course, the various components and amounts thereof in the resultant
materials described in the preceding discussion may vary depending
on the particular starting materials, the process conditions, and
other factors.
[0036] A solution of the resultant material also generally does not
have an intense color. While not wishing to be limited by theory,
it is believed that the reduction in color is due in part to the
reduction in phenolic components. For example, using a
spectrophotometer or colorimeter, a solution of the starting
(unmodified) raw material can generally exhibit the following
colors: A (1%, 1 cm) 400 nm: 1.490; A (1%, 1 cm) 500 nm: 0.234; A
(1%, 1 cm) 600 nm: 0.047; and A (1%, 1 cm) 700 nm: 1.490 (i.e., the
absorption of a 1 percent solution in a 1 cm thick cell). After the
methods herein, a solution of the resultant material preferably
exhibits the following colors: A (1%, 1 cm) 400 nm: 0.074; A (1%, 1
cm) 500 nm: 0.006; A (1%, 1 cm) 600 nm: 0.002; and A (1%, 1 cm) 700
nm: 0.000. Accordingly, there is about 95 to about 100 percent
decrease in color within 400 to 700 nm wavelengths.
[0037] In addition, advantages and embodiments of the process
described herein are further illustrated by the following examples;
however, the particular conditions, flow schemes, materials and
amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this method. All percentages are by weight unless otherwise
indicated.
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