U.S. patent application number 13/984562 was filed with the patent office on 2013-12-05 for oil compositions.
This patent application is currently assigned to Cargill, Incorporated. The applicant listed for this patent is Falk Bruse, Marcus Bernardus Kruidenberg. Invention is credited to Falk Bruse, Marcus Bernardus Kruidenberg.
Application Number | 20130323394 13/984562 |
Document ID | / |
Family ID | 44802599 |
Filed Date | 2013-12-05 |
United States Patent
Application |
20130323394 |
Kind Code |
A1 |
Bruse; Falk ; et
al. |
December 5, 2013 |
OIL COMPOSITIONS
Abstract
A refined oil composition having a reduced 3-MCPD ester and/or
glycidyl ester content and methods of preparation thereof.
Inventors: |
Bruse; Falk; (Drensteinfurt,
DE) ; Kruidenberg; Marcus Bernardus; (Oostvoorne,
NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bruse; Falk
Kruidenberg; Marcus Bernardus |
Drensteinfurt
Oostvoorne |
|
DE
NL |
|
|
Assignee: |
Cargill, Incorporated
Wayzata
MN
|
Family ID: |
44802599 |
Appl. No.: |
13/984562 |
Filed: |
February 9, 2012 |
PCT Filed: |
February 9, 2012 |
PCT NO: |
PCT/EP12/00593 |
371 Date: |
August 9, 2013 |
Current U.S.
Class: |
426/590 ;
426/417; 426/601 |
Current CPC
Class: |
A23L 5/21 20160801; A23L
5/273 20160801; A23L 33/115 20160801; C11B 3/10 20130101; A23L 2/52
20130101; A23D 9/04 20130101; C11B 3/001 20130101; A23V 2002/00
20130101; C11B 3/12 20130101 |
Class at
Publication: |
426/590 ;
426/417; 426/601 |
International
Class: |
A23D 9/04 20060101
A23D009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2011 |
EP |
11001076.6 |
Claims
1.-16. (canceled)
17. A process for the production of a refined oil having a reduced
3-MCPD ester and/or glycidyl ester content, the process comprising:
subjecting an oil to the following steps, in order: (a) a bleaching
step; (b) a deodorization step; (c) a final bleaching step; and (d)
a final deodorization step, wherein the final deodorization step
(d) is carried out at a temperature at least 40.degree. C. lower
than deodorization step (b).
18. The process of claim 17, wherein steps (b) to (d) comprise: i)
introducing the oil into a deodorization apparatus; ii) removing
the oil from the deodorization apparatus via an oil outlet
positioned such that the oil leaves the deodorization apparatus
after an initial deodorization; iii) subjecting the oil to a final
bleaching step; and iv) reintroducing the oil to the deodorization
apparatus via an oil inlet positioned such that the oil enters the
deodorization apparatus and is subjected to a final deodorization
at a temperature at least 40.degree. C. lower than the initial
deodorization.
19. A process for the production of a refined oil having a reduced
3-MCPD ester and/or glycidyl ester content, the process comprising:
subjecting an oil to the following steps, in order: (a) a bleaching
step; (b) a deodorization step; and (c) a final bleaching step,
wherein the final bleaching step (c) is carried out at a
temperature below 80.degree. C.
20. The process of claim 19, wherein the final bleaching step (c)
is performed in an oxygen-poor environment.
21. The process of claim 17, further comprising at least one alkali
treatment step selected from the group consisting of an alkali
refining step and an alkali interesterification step.
22. The process of claim 17, further comprising an alkali refining
step carried out prior to bleaching step (a).
23. The process of claim 17, further comprising an alkali
interesterification step carried out between deodorization step (b)
and final bleaching step (e).
24. the process of claim 19 further comprising at least one alkali
treatment step selected from the group consisting of an alkali
refining step and an alkali interesterification step.
25. The process of claim 19, further comprising an alkali refining
step carried out prior to bleaching step (a).
26. The process of claim 19, further comprising an alkali
interesterification step carried out between deodorization step (b)
and final bleaching step (c).
27. The process of claim 17, wherein the refined oil has a combined
3-MCPD ester and glycidyl ester content of less than 5 ppm and a
taste value, measured according to Method C, of 8 or more.
28. The process of claim 19, wherein the refined oil has a combined
3-MCPD ester and glycidyl ester content of less than 5 ppm and a
taste value, measured according to Method C, of 8 or more.
29. The process of claim 17, wherein the refined oil has an
undetectable glycidyl ester content and a taste value, measured
according to Method C, of 8 or more.
30. The process of claim 19, wherein the refined oil has an
undetectable glycidyl ester content and a taste value, measure
according to Method C, of 8 or more.
31. A refined oil obtainable by the process of claim 17.
32. A refined oil obtainable by the process of claim 19.
33. A refined palm oil having a combined 3-MCPD ester and glycidyl
ester content of less than 1 ppm and a taste value, measured
according to Method C, of 8 or more.
34. A refined oil having an undetectable glycidyl ester content,
the refined oil having a taste value, measured according to Method
C, of 8 or more.
35. A beverage or foodstuff comprising the refined oil prepared by
the process of claim 27.
36. A beverage or foodstuff comprising the refined oil prepared by
the process of claim 28.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to novel oil compositions for
use in the preparation of beverages and/or foodstuffs and to
methods for their manufacture. In particular, the invention relates
to refined oil compositions which have a very low 3-MCPD ester
and/or glycidyl ester content.
BACKGROUND OF THE INVENTION
[0002] Crude oils, as extracted from their original source, are not
suitable for human consumption due the presence of high levels of
contaminants--such as free fatty acids, phosphatides, soaps and
pigments--which may be toxic or may cause an undesirable colour,
odour or taste. Crude oils are therefore refined before use. The
refining process typically consists of three major steps:
degumming, bleaching and deodorizing. An oil obtained after
completion of the refining process (called a "refined oil") is
normally considered suitable for human consumption and may
therefore be used in the production of any number of foods and
beverages.
[0003] Unfortunately, it has now been found that the refining
process itself contributes to the introduction, into the refined
oil, of high levels of 3-monochloropropane-1,2-diol fatty acid
esters (3-MCPD esters) and glycidyl esters--typically in an amount
of about 10-25 ppm. 3-MCPD esters and glycidyl esters are produced
as a result of the oils being exposed to high temperatures during
processing, in particular during deodorization. Both glycidyl
esters and 3-MCPD esters are associated with a possible
carcinogenic effect. In particular, there is a risk that 3-MCPD
esters could be converted to free 3-MCPD in the body during
digestion. Free 3-MCPD, when present in the body at high
concentrations, is known to cause hyperplasia (increased cell
count) in the renal tubes of animals which, in turn, can lead to
the formation of tumours. A similar effect is observed for glycidyl
esters which are converted to free glycidol in the body. As such,
scientific expert bodies of the EU, the World Health Organisation
and the Food and Agriculture Organisation have set a tolerable
daily intake (TDI) of 2 micrograms free 3-MCPD per kilogram body
weight for humans.
[0004] Assuming that all 3-MCPD esters present in refined oils
would be converted to free 3-MCPDs, it has been calculated that a
man consuming 100 g of vegetable margarine a day could exceed the
above TDI by up to five times. Similarly, a baby being fed with
formula (which contain about 25% fat by weight) could be exceeding
the TDI by up to 20 times.
[0005] Thus, although there is still a lot of uncertainty around
the effect of 3-MCPD esters and glycidyl esters on the human body,
a number of regulatory bodies, including for instance the German
Federal Institute for Risk Assessment, have nonetheless recommended
that efforts be made to lower levels of 3-MCPD esters and glycidyl
esters in refined oils. A concerted effort has therefore been made,
in the oil processing industry, to identify ways of reducing 3-MCPD
ester and glycidyl ester levels in refined oils.
[0006] To date, two main approaches have been suggested: the first
involves sourcing crude oils which have very low levels of 3-MCPD
precursors, meaning that the final refined oil will naturally have
a lower 3-MCPD ester level than a standard refined oil.
Unfortunately, this solution is costly and unsustainable at high
volumes due to a lack of available "low 3-MCPD" oil sources. As
such, the main method used in the industry to reduce 3-MCPD ester
content has been to use low-temperature deodorization in order to
reduce the rate of conversion from 3-MCPD precursors to 3-MCPD
esters. Unfortunately, even at the lowest possible temperatures (a
minimum temperature being required to maintain food safety), 3-MCPD
esters will be formed in quantities that exceed maximum levels
desired by the food industry. Of course, this could partially be
addressed by combining low-temperature deodorization with low
3-MCPD precursor crude oils but this solution will still suffer
from the obstacles and costs associated with sourcing such
oils.
[0007] A further suggestion for reducing 3-MCPD ester content is
made in WO2010/036450 (Sud-Chemie). It is based on a modified
refining process which uses very intensive bleaching (with high
amounts of bleaching clays). Unfortunately, this solution is
prohibitively costly for use on an industrial scale and is not
sufficiently effective: 3-MCPD ester levels are not sufficiently
reduced and, moreover, the process results in high yield losses for
the oil overall.
[0008] It has been observed that bleaching can cause a reduction in
3-MCPD ester levels (see WO2011/069028A1). However, bleaching also
increases free fatty acid content and negatively affects taste. It
must therefore be followed by a further refining step, typically
deodorization, to render the oil fit for consumption.
[0009] There is therefore still a need in the industry to identify
an efficient and effective method of producing refined oils with an
acceptable taste and with very low 3-MCPD ester and/or glycidyl
ester levels. The present invention provides such a process.
SUMMARY OF THE INVENTION
[0010] According to a first aspect of the present invention, there
is provided a process for the production of a refined oil having a
reduced 3-MCPD ester and/or glycidyl ester content characterized in
that it comprises subjecting an oil to the following steps, in
order: (a) a bleaching step, (b) a deodorization step, (c) a final
bleaching step, and (d) a final deodorization step, wherein final
deodorization step (d) is carried out at a temperature at least
40.degree. C. lower than deodorization step (b), preferably at a
temperature below 190.degree. C.
[0011] According to a further aspect of the present invention,
there is provided a process for the production of a refined oil
having a reduced 3-MCPD ester and/or glycidyl ester content
characterized in that it comprises subjecting an oil to the
following steps, in order: (a) a bleaching step, (b) a
deodorization step, and (c) a final bleaching step, wherein the
final bleaching step (c) is carried out at a temperature below
80.degree. C., and preferably in an oxygen-poor environment.
[0012] According to certain embodiments, the above processes may
further comprise an alkali treatment step selected from an alkali
refining step and an alkali interesterification step.
[0013] According to yet another aspect of the present invention,
there is provided a refined oil, preferably a refined palm oil,
obtainable according to one of the above processes. In particular,
there is provided a refined oil having a combined 3-MCPD
ester+glycidyl ester content of less than 5 ppm and a taste value,
measured according to Method C, of 8 or more. There is also
provided a refined oil having a non-detectable glycidyl ester
content. Beverages and/or foodstuffs comprising such refined oils
are also part of the present invention.
DETAILED DESCRIPTION
[0014] The present invention provides a process for the production
of refined oils having a reduced 3-MCPD ester and/or glycidyl ester
content.
[0015] Refined oils are oils that have undergone full refining and
are suitable for use in their designated end application. In
particular, they will be suitable for human consumption.
Traditionally, refining has included at least a degumming step, a
bleaching step and a deodorizing step, although other refining
steps may also be used. A non-refined oil (i.e. an oil that has not
been subjected to any refining steps) will be referred to as a
crude or virgin oil. Such crude oils might be obtained by
extraction with solvents (such as hexane) followed by evaporation
of the solvent. The mixture of oil and solvent is called miscella
but, for simplicity, will also be referred to herein as "crude
oil". A partially refined oil is one that has been subjected to one
or more refining steps but is not yet suitable for use in its end
application. When the term "oil" is used alone, without prefix, it
may refer to a non-, partially and/or fully refined oil, its
meaning becoming apparent from context.
Special Processing
[0016] The present invention provides a process for the production
of a refined oil having a reduced 3-MCPD ester and/or glycidyl
ester content characterized in that it comprises a bleaching step
followed by a deodorization step and in that it comprises a mild
final refining step, i.e. a final beaching and/or deodorization
step carried out under conditions which will limit the formation of
undesirable substances.
[0017] According to one possible embodiment, the process will
comprise subjecting an oil to the following steps, in order: (a) a
bleaching step, (b) a deodorization step, (c) a final bleaching
step, and (d) a final deodorization step, wherein the final
deodorization of step (d) is carried out at a temperature at least
40.degree. C. lower than the deodorization of step (b). When
carried out under such conditions, the final deodorization will be
referred to as a "mild deodorization step". Preferably, the final
deodorization will be performed at a temperature of 190.degree. C.
or less, more preferably at a temperature of 180.degree. C. or
less, even more preferably at a temperature of 160.degree. C. or
less, for example at a temperature in the range of 140-160.degree.
C. or 130-160.degree. C.
[0018] According to another possible embodiment, the process will
comprise subjecting an oil to the following steps, in order: (a) a
bleaching step, (b) a deodorization step, and (c) a final bleaching
step, wherein the final bleaching step (c) is carried out at a
temperature below 80.degree. C. When carried out under such
conditions, the final bleaching step will be referred to as a "mild
bleaching step". Under these conditions, it has been found that a
further deodorization is not necessary. Preferably, the final
bleaching step will be performed at a temperature of 70.degree. C.
or less, for example at a temperature in the range of 50-70.degree.
C. Ideally, it will be performed in an oxygen-poor environment. An
oxygen-poor environment will be understood as an environment or
set-up capable of significantly reducing the oil's contact with
oxygen. Preferably, the oxygen-poor environment will be
substantially devoid of oxygen. The final bleaching step may, for
instance, be performed in an inert gas (e.g. under nitrogen
atmosphere) or in a fixed bed column (or similar structured filter
systems). Although it should not be necessary, if a subsequent
deodorization is used, it will be a final deodorization as
described above (i.e, preferably performed at a temperature of
190.degree. C. or less).
Bleaching
[0019] Bleaching is a process whereby impurities are removed to
improve the color and flavor of the oil. It is typically performed
prior to deodorization. The nature of the bleaching step will
depend, at least in part, on the nature and quality of the oil
being bleached. Generally, a crude or partially refined oil will be
mixed with a bleaching agent which combines with oxidation products
(e.g. peroxides), trace phosphatides, trace soaps, pigments and
other compounds to enable their removal. The nature of the
bleaching agent can be selected to match the nature of the crude or
partially refined oil to yield a desirable bleached oil. Bleaching
agents generally include natural or "activated" bleaching clays,
also referred to as "bleaching earths", activated carbon and
various silicates. A skilled person will be able to select a
suitable bleaching agent from those that are commercially available
based on the oil being refined and the desired end use of that
oil.
[0020] The processes of the present invention will include at least
two bleaching steps. If the final bleaching step is followed by a
deodorization step, these may be the same or similar (e.g. with the
same bleaching agents and performed under similar conditions)--the
final bleaching step could even be more intense that the preceding
one(s). Preferably, however, the final bleaching step will be a
mild bleaching step, i.e. less intensive than the preceding one(s).
For example, the final bleaching step may be performed with less
bleaching agent (or less active bleaching agent), at lower
temperatures and/or with a reduced retention time, or in bleaching
equipment that will have less impact on taste and free fatty acid
formation (i.e. in an oxygen-poor environment as described
above).
[0021] Thus, the process of the present invention will include a
first bleaching step followed by a first deodorization step and a
final bleaching step which may, or may not, be followed by a final
deodorization step.
Deodorization
[0022] Deodorization is a process whereby free fatty acids (FFAs)
and other volatile impurities are removed by treating (or
"stripping") a crude or partially refined oil with steam, nitrogen
or other inert gasses. The deodorization process and its many
variations and manipulations are well known in the art and the
deodorization step(s) of the present invention may be based on a
single variation or on multiple variations thereof.
[0023] For instance, deodorizers may be selected from any of a wide
variety of commercially available systems, including both
multi-chamber deodorizers (such as those sold by Krupp of Hamburg,
Germany; De Smet Group, S.A. of Brussels, Belgium; Gianazza
Technology s.r.l. of Legnano, Italy; Alfa Laval AB of Lund, Sweden,
or others) and multi-tray deodorizers (such as those sold by Krupp,
DeSmet Group, S.A., and Crown Ironworks of the United States).
[0024] If the process of the present invention includes two (or
more) deodorization steps, a separate deodorizer will typically be
used for each deodorization step. Each deodorizer may be of the
same make, type, set-up, etc. or they may be different--provided
that, if more than one deodorization step is used, the final
deodorization is a mild deodorization step. According to one
possible set-up, however, the multiple deodorizations may be
performed in a single deodorization apparatus. According to this
embodiment, an oil outlet would be provided such that the oil would
leave the deodorizer after initial high-temperature deodorization
(by which it is meant that the initial deodorization will include
at least one high-temperature deodorization stage). It would then
be bleached and reintroduced into the deodorizer via an inlet
positioned such that the oil would re-enter the deodorizer and be
subjected to less high-temperature deodorization (i.e.
deodorization at a temperature at least 40.degree. C. lower than
the highest deodorization temperature used during the initial
deodorization). This could be done, for example, in a multi-tray or
multi-chamber deodorizer. In these deodorizers, heat exchangers are
positioned such that, for instance, in the top tray or chamber,
oils are subjected to deodorization at 270.degree. C. In the next
tray or chamber, the deodorization temperature will be 250.degree.
C., and so on until, in the bottom trays, the deodorization
temperatures are 140.degree. C. or 120.degree. C. Thus, the oil
outlet could be positioned below a first set of trays/chambers such
that the oil would leave the deodorizer after deodorization at
200.degree. C., for example. The oil inlet would then be positioned
such that the oil would be reintroduced into a tray/chamber in
which deodorization is performed at 190.degree. C. or less. It
would then be allowed to continue through the tray/chambers until
it reached the end/bottom of the deodorizer.
[0025] Deodorization is typically carried out at elevated
temperatures and reduced pressure to better volatilize the FFAs and
other impurities. The precise temperature and pressure may vary
depending on the nature and quality of the oil being processed. The
pressure, for instance, will preferably be no greater than 10 mm Hg
but certain embodiments may benefit from a pressure below or equal
to 5 mm Hg, e.g. 1-4 mm Hg. The temperature in the deodorizer may
be varied as desired to optimize the yield and quality of the
deodorized oil. At higher temperatures, reactions which may degrade
the quality of the oil will proceed more quickly. For example, at
higher temperatures, cis-fatty acids may be converted into their
less desirable trans form. Operating the deodorizer at lower
temperatures may minimize the cis-to-trans conversion, but will
generally take longer or require more stripping medium or lower
pressure to remove the requisite percentage of volatile impurities.
As such, deodorization is typically performed at a temperature in a
range of 200 to 280.degree. C., with temperatures of about
220-270.degree. C. being useful for many oils (note: the
temperatures reflect the temperatures reached by the oils in the
deodorizer rather than, for example, that of the steam used during
the process).
[0026] According to one embodiment of the present invention, a
first deodorization step will be carried out at a temperature
within these typical ranges (i.e. from 200 to 280.degree. C.,
preferably from 220 to 270.degree. C.). For palm oil, the preferred
temperature range for the first deodorization will be 240 to
270.degree. C. If used, the final deodorization step will be
performed at a temperature at least 40.degree. C. lower than the
first deodorization step. Preferably, the final deodorization step
will be performed at a temperature of 190.degree. C. or less,
preferably at a temperature of 180.degree. C. or less, more
preferably at a temperature of 160.degree. C. or less, for example
at a temperature in the range of 140-160.degree. C. or
130-160.degree. C.
[0027] Thus, the process of the present invention will include a
first bleaching step and a first deodorization step followed by a
final bleaching step and, optionally, a final deodorization step.
It may also include one or more alkali treatment steps.
Alkali Treatment
[0028] According to a preferred embodiment, the process of the
present invention may also include one or more alkali treatment
steps. The term "alkali treatment" as used herein should not be
understood as referring only to the traditional chemical refining
process known as "alkali refining" but, instead, to any treatment
of the oil with an alkali (i.e. to any process in which the crude
or partially refined oil is brought into contact with an alkali),
as will become apparent below.
[0029] Alkali Refining
[0030] According to one specific embodiment, the alkali treatment
will consist of an alkali refining type step comprising: (a) mixing
a crude or partially refined oil with an aqueous alkali solution to
produce a mixture of partially refined oil and soapstock; (b)
separating off the soapstock (e.g. using a centrifuge or a settling
tank); and (c) washing the partially refined oil (preferably with
water at a temperature in the range 70-105.degree. C.). The washed,
partially refined oil can then be delivered to the next refining
step (note: in the case of miscella, alkali refining will result in
a neutralized, washed miscella which will first have to be
subjected to evaporation before the oil can be delivered to the
next refining step).
[0031] Alkalis which can be used for alkali refining will typically
be strong alkalis such as sodium hydroxide or sodium carbonate.
Sodium hydroxide, for instance, will preferably be used at a
concentration of approximately 25%. This and other possible
variations of the alkali refining step will be apparent to the
person skilled in the art and need not, therefore, be described in
detail here.
[0032] Without wishing to be bound by theory, it is thought that
this alkali refining step will allow for 3-MCPD ester and/or
glycidyl ester precursors to be removed from the crude or partially
refined oil, thus reducing the overall number of 3-MCPD esters
and/or glycidyl esters formed during further processing (e.g.
during deodorizing). As such, when used, this type of alkali
treatment step will preferably be performed prior to the first
deodorization step, more preferably prior to the first bleaching
step.
[0033] Alkali Interesterification
[0034] According to a further embodiment of the present invention,
the alkali treatment step may be an alkali interesterification
step, performed by bringing a crude or partially refined oil into
contact with an alkaline interesterification catalyst.
[0035] Interesterification is used to change the acyl-glycerol
profile of an oil (in particular by exchanging fatty acids between
different triglycerides). Again, without wishing to be bound by
theory, it is thought that the alkali interesterification step
allows for the removal of 3-MCPD esters and/or glycidyl esters
themselves from a treated oil. As such, when used, the alkali
interesterification step will preferably be performed after the
first deodorization step and, more preferably, prior to the final
bleaching step.
[0036] A number of alkaline interesterification catalysts are known
in the art. These include, by way of example only, sodium
alcoholates and potassium alcoholates such as sodium methoxide
and/or sodium ethoxide; sodium stearate; sodium hydroxide and
potassium hydroxide. Any of these may be used for the purposes of
the present invention. According to one particular embodiment,
sodium methoxide is used, preferably at levels of approximately
0.05 to 0.1% by weight. Advantageously, the oil to be treated will
be brought into contact with the alkaline interesterification
catalyst under vacuum and at a temperature in the range of 80 to
120.degree. C.
[0037] Contact will preferably be maintained for 30 to 90 minutes.
This will typically result in full interesterification of the oil
although it should be noted that actual interesterification is not
thought to be necessary to achieve reduced 3-MCPD ester levels.
[0038] According to one particular embodiment, the process of the
present invention may include multiple alkali treatment steps. For
example, it may include an alkali refining type step prior to the
first deodorization and an alkali interesterification step
subsequent to the first deodorization. Other possible permutations
will be apparent to a person skilled in the art.
[0039] Thus, by way of illustration, possible embodiments of the
present invention include:
(I) subjecting an oil to (a) an alkali refining step, (b) a
bleaching step, (c) a deodorization step, (d) a final bleaching
step, and (e) a final, mild deodorization step. (II) subjecting an
oil to (a) a bleaching step, (b) a deodorization step, (c) an
alkali interesterification step, (d) a final bleaching step, and
(e) a final, mild deodorization step. (III) subjecting an oil to
(a) an alkali refining step, (b) a bleaching step, (c) a
deodorization step, (d) an alkali interesterification step, (e) a
final bleaching step, and (f) a final, mild deodorization step.
(IV) subjecting an oil to (a) an alkali refining step, (b) a
bleaching step, (c) a deodorization step, and (d) a final, mild
bleaching step. (V) subjecting an oil to (a) a bleaching step, (b)
a deodorization step, (c) an alkali interesterification step and
(d) a final, mild bleaching step. (VI) subjecting an oil to (a) an
alkali refining step, (b) a bleaching step, (c) a deodorization
step, (d) an alkali interesterification step and (e) a final, mild
bleaching step.
Additional Steps
[0040] In addition to the refining steps described above, the
process of the present invention may include one or more additional
refining or treatment steps. For example, the crude or partially
refined oil may be subjected to one or more degumming steps. Any of
a variety of degumming processes known in the art may be used. One
such process (known as "water degumming") includes mixing water
with the oil and separating the resulting mixture into an oil
component and an oil-insoluble hydrated phosphatides component,
sometimes referred to as "wet gum" or "wet lecithin".
Alternatively, phosphatide content can be reduced (or further
reduced) by other degumming processes, such as acid degumming
(using citric or phosphoric acid for instance), enzymatic degumming
(e.g., ENZYMAX from Lurgi) or chemical degumming (e.g., SUPERIUNI
degumming from Unilever or TOP degumming from
VandeMoortele/Dijkstra CS). If a degumming step is used, it will
preferably precede the first bleaching step.
[0041] The process may also optionally include one or more
neutralization steps (before the first bleaching), any kind of
dewaxing (at any place in the process), fractionation (at any place
in the process),
[0042] The process of the invention may also include one or more
chemical or enzymatic modification steps, including for instance
hydrogenation and/or interesterification. Hydrogenation will
preferably be performed before either the first deodorization step
or the final bleaching step. Chemical interesterification will
preferably be performed after the initial deodorization and prior
to the final deodorization, if used. If the oil being treated
according to the present process has a relatively low FFA content,
it may also be performed prior to the initial deodorization.
Enzymatic interesterification can be performed at any point in the
process and will preferably be performed with a lipase enzyme.
Advantageously, it has been found that when performed after the
initial deodorization step, enzymatic interesterification could be
used as an alternative to the second bleaching step, or could be
carried out at the same time, in the same process (e.g. batch wise
or in a fixed bed column).
[0043] The process may also include--or indeed be preceded or
followed by--one or more blending steps. It may be desirable, for
instance, to blend oils of different types or from multiple
sources. For example, a number of crude or partially refined oils
could be blended before the first bleaching step. Alternatively,
two or more refined oils could be blended after the final refining
step or partially refined oils could be blended at an intermediate
stage.
[0044] Many permutations and variations of the present process are
possible. These will be apparent to a skilled person depending on
the nature of the crude oil being used as a starting material
and/or on the type of refined oil being produced and its desired
end use. The only restriction that will be imposed is that the oil
should not be subjected to any treatment steps, after the final
mild refining (i.e. bleaching and/or deodorization) step, which
could significantly increase levels of 3-MCPD esters and/or
glycidyl ester in the oil beyond a target level.
Products
[0045] Refined oils obtained through the above process are also
part of the present invention. Specifically, there is provided a
refined oil having a reduced 3-MCPD ester and/or glycidyl ester
content. The refined oils may be derived from crude or partially
refined oils of any type, source or origin. They may be derived,
for example, from one or more vegetable and/or animal sources and
may include oils and/or fats from a single origin or blends of two
or more oils and/or fats from different sources or with different
characteristics. They may be derived from standard oils or from
specialty oils such as low 3-MCPD oils, from modified or unmodified
oils and/or fats (i.e. from oils in their natural state or oils
that have been subjected to a chemical or enzymatic modification or
to fractionation) and so on. Preferably, they will be derived from
vegetable oils or vegetable oil blends. Examples of suitable
vegetable oils include: soybean oil, corn oil, cottonseed oil, palm
oil, palm kernel oil, peanut oil, rapeseed oil, safflower oil,
sunflower oil, sesame seed oil, rice bran oil, coconut oil, canola
oil and any fractions or derivatives thereof. According to a
particularly preferred embodiment, the refined oils of the present
invention will be derived from palm oil.
[0046] Different oils contain different levels of 3-MCPD ester and
glycidyl ester precursors and therefore give rise to different
levels of 3-MCPD esters and glycidyl esters after processing. The
refined oils of the present invention will have a reduced 3-MCPD
ester and/or glycidyl ester content, where the term "reduced"
refers to a 3-MCPD ester and/or glycidyl ester content which is
lower than that of a corresponding oil obtained by standard
refining (i.e. standard degumming, bleaching and deodorization).
Preferably, the refined oils will have a combined 3-MCPD ester and
glycidyl ester content which is at least 50% lower than that of the
corresponding oil obtained by standard refining. More preferably,
the combined 3-MCPD ester and glycidyl ester content will be at
least 60% lower, more preferably at least 70% lower, more
preferably at least 80% lower, more preferably at least 90%
lower.
[0047] Taking palm oil by way of example, when refined by standard
physical refining (degumming, bleaching, deodorization), it has a
combined 3-MCPD ester and glycidyl ester content of 15 to 25 ppm.
By comparison, a refined palm oil of the invention (or obtainable
according to the process of the invention) will have a combined
content of 3-MCPD esters and glycidyl esters ("M+G") of no more
than 5 ppm, preferably no more than 3 ppm, more preferably no more
than 2 ppm, more preferably no more than 1 ppm, more preferably no
more than 0.5 ppm. According to certain particular embodiments, it
will have a combined M+G content of 2.5 to 5 ppm. Alternatively, it
may have a combined M+G content of 1 to 3 ppm. Alternatively, it
may have a combined M+G content of 1 to 2.5 ppm. Alternatively,
they it may have a combined M+G content of 0.3 to 1.7 ppm.
Alternatively, it may have a combined M+G content of 0.5 to 1
ppm.
[0048] Unless specified otherwise, the combined content of 3-MCPD
esters and glycidyl esters will be determined using Method A (DGF
Standard Methods Section C (Fats) C-III 18(09) Option A. 3-MCPD
ester content alone can be determined by Method B (DGF Standard
Methods Section C (Fats) C-III 18(09) Option B). Glycidyl ester
content can thus be calculated as the result of Method A minus the
result of Method B.
[0049] Advantageously, the process of the present invention will be
capable of producing oils with undetectable levels of glycidyl
esters. By "undetectable", it is meant that any glycidyl esters
that are measured will be within the margin of error the test
method. For instance, the refined oil may have a glycidyl ester
content of 0.05 ppm or less, more preferably of 0.01 ppm or
less.
[0050] The refined oils will also, preferably, have a FFA content
of less than 0.1%, more preferably less than 0.05% by weight--to
avoid off-putting or unpleasant odor and/or taste. In fact, the
refined oils of the present invention will ideally have a taste
value, measured according to Method C, of 8 or more, preferably of
9 or more.
Beverages and Foodstuffs
[0051] The refined oils of the present invention may be packaged
and sold as such (i.e. as low 3-MCPD/low glycidyl ester oils) or
they may be further blended with one or more other oils or oil
compositions and/or with one or more other ingredients, including,
if desired, with one or more additives. Where the refined oils of
the invention are blended with one or more other oils, these will
preferably be deodorized oils and, even more preferably, refined
oils obtainable according to the process of the invention.
[0052] These refined oils and refined oil blends may be used for
any desired purpose, e.g. in the food and beverage industry. Thus,
according to one particular embodiment, the present invention
provides a food and/or beverage composition comprising a refined
oil or refined oil blend as described above.
[0053] The refined oils of the invention may, for example, be used
in bakery products (e.g. cakes, breads, doughs, pastries, batters,
etc.), culinary products (e.g. bouillons), frozen products (e.g.
pizzas, fries, etc.) or dairy products (e.g. cheese products,
yogurts, ice-creams, etc.), in fat-based products per se (such as
margarines or frying oils), in infant formulas, nutritional
supplements and so on, just like any other oil or oil blend. The
refined oils of the present invention will be particularly suitable
for use in infant formula and/or other infant nutrition products.
Preferably, they will be used in infant nutrition products to
replace other oils and/or fats.
METHODS and EXAMPLES
Method C:
[0054] The flavor of refined oils and fats is an important
criterion for judging the quality of the oil; mainly products of
oxidation are recognized during tasting.
[0055] Taste Area
[0056] The tasting testing area should be located in a clean and
neutral surrounding.
[0057] Sample Taking
[0058] Each batch of refined oils/fats should be evaluated on
taste. A representative sample of a tank shall be taken to taste
the oil. Taking of the sample should be done according to the
applicable local instruction. To take a representative sample
sufficient flushing might be needed. If oils are stored before
testing, they must be stored appropriately (i.e. not at high
temperatures).
[0059] Sample Preparation/Materials
TABLE-US-00001 Utensils used for tasting Waste cups White
background Drinking water at 38.degree. C. Clean cups
Microwave/oven
[0060] When the sampling bottles are dirty either on the outside or
on the inside; pour the oil/fat into a glass beaker, to prevent off
flavors from the dirty bottle. Before the tasting can start the
samples must be at specific temperatures: vegetable oils are tasted
at room temperature; fats are tasted at a temperature of
.+-.50.degree. C. (or 10.degree. C. above melting point). Fats can
be warmed in an oven or microwave to reach this temperature.
[0061] Odor and Flavoring Testing Methods
[0062] 1 or 2 taste panel members (who are trained and qualified to
taste oils) should taste-test each batch of refined oils/fat. They
must first clean their mouth with water (moderately warm about
38.degree. C.) and evaluate the oil/fat for odor (swirling the
oil/fat before sniffing). 10 ml of the oil/fat is then taken into
the mouth and thoroughly rolled throughout the mouth (at least 10
s, without swallowing). The oil/fat is then spat out into a waste
cup and any after-taste is noted. If a further samples needs to be
tested, the tester must rinse their mouth with warm water (about
38.degree. C.) between each sample.
[0063] The following must be taken into account: fats should not
starch in the mouth, nor be too hot as this influences the
taste-feeling; to release the flavors in oil/fats you must
alternately suck up some air through the mouth and circulate with
the tongue; taste-testing must not be performed within half an hour
of smoking, drinking coffee or eating. In general, the first sample
will not have such a good score. This is because the taste person
has to overcome the aversion from taking oil/fat in the mouth.
Therefore it is recommended to re-taste the first sample after 3 or
4 tasted oil/fats.
[0064] Evaluation
[0065] The oil is evaluated using a rating scale to judge the
quality. This rating scale is based on the scales mentioned in AOCS
Cg 2-83, and goes from 1 till 10--with 8 or higher being considered
good, i.e. having a bland taste.
TABLE-US-00002 Score Intensity level 10 Zero 9 Trace 8 Faint 7
Slight 6 Mild 5 Moderate 4 Definite 3 Strong 2 Very strong 1
Extreme
[0066] Bland is defined as an oil/fat that has no off-taste, which
negatively influences the flavor of the oil. It does not mean that
the oil has no flavor.
Example 1
Reference
[0067] Crude palm oil with FFA of 5.52% was alkali refined (at
industrial scale) using 5.4% sodium hydroxide solution (20%).
Neutralization was carried out by mixing and centrifugation at
105.degree. C. Washing after separation is done with 10% water
under same conditions. Bleaching with 1% Taiko classic G was done
for 37 min at 98.degree. C. Deodorization was carried out for 50
min at 240.degree. C. and 4 mbar using 2% sparge steam.
[0068] From this standard production samples were taken, showing on
average: 0.65 ppm 3-MCPD, and 2.13 ppm 3-MCPD+Glycidol (i.e. 0.99
ppm glycidol).
[0069] After 2.sup.nd bleaching of this oil with 0.5% bleaching
clay (Taiko classic G) for 30 min at 100.degree. C., the product
showed 0.65 ppm 3-MCPD and 0.66 ppm 3-MCPD+Glycidol. The taste,
however, had a strong off-flavor suggesting a significant increase
in FFA levels. A further physical refining under standard
conditions was therefore performed and resulted, on average, in
3.43 ppm 3-MCPD and 10.02 ppm 3-MCPD+Glycidol (meaning 4.42 ppm
Glycidol).
Example 2
Mild Final Deodorization
[0070] An alkali refined palm oil obtained according above
description (without the 2.sup.nd bleaching and deodorization) was
re-bleached with 0.5% bleaching clay (lzegem BC) and deodorized at
temperatures of 183.7.degree. C., 188.1.degree. C. and
196.3.degree. C., respectively. The oils obtained were analyzed and
the results are shown below:
TABLE-US-00003 Deo. Temp. 3-MCPD (ppm) 3-MCPD + Glycidol (ppm)
Glycidol (ppm) 196.3.degree. C. 0.73 0.85 0.080 188.1.degree. C.
0.67 0.71 0.027 183.7.degree. C. 0.67 0.68 0.007
[0071] As can be seen from these results, the final mild refining
step results in oils with a very low 3-MCPD ester and glycidol
ester levels. In fact, at deodorization temperatures below
190.degree. C., glycidyl ester levels are effectively
undetectable.
Example 3
Taste Analysis
[0072] In a pilot system for bleaching and deodorization, 25 kg of
physically refined palm oil (standard RBD Palm Oil) was re-bleached
with 0.5% Taiko classic G at 100.degree. C. The product was
filtered and then deodorized at temperatures between 120 and
220.degree. C. At each set-point, the temperature was maintained
for 30 min, a taste sample was taken and the temperature was then
increased to the next set-point. Taste analysis (according to
Method C) is given in the table below, demonstrating that, from
140.degree. C. onwards, all samples were as good in taste as the
standard RBD Palm Oil and that, even at 120.degree. C., the samples
still have a very good, bland flavor.
TABLE-US-00004 Sample: Taste RBD Palm Oil 9 RBD re-bleached palm
oil 4 RBD re-bleached and re-deodorized @ 120.degree. C. 8 RBD
re-bleached and re-deodorized @ 140.degree. C. 9 RBD re-bleached
and re-deodorized @ 160.degree. C. 9 RBD re-bleached and
re-deodorized @ 180.degree. C. 9 RBD re-bleached and re-deodorized
@ 200.degree. C. 9 RBD re-bleached and re-deodorized @ 220.degree.
C. 9
Example 4
[0073] In a pilot system for bleaching and deodorization, 25 kg of
physically refined (RDB) palm oil was re-bleached with 0.5% Taiko
classic G at 100.degree. C. The product was filtered and deodorized
at 140.degree. C. Taste and 3-MCPD and Glycidol data are given in
the table below, demonstrating that, at 140.degree. C., taste was
again as good as for the RBD palm oil being tested, and that
3-MCPD/Glycidol values did not increase again after further
deodorization.
TABLE-US-00005 3-MCPD + Sample: Taste Glycidol 3-MCPD RBD Palm Oil
8 21.29 2.86 RBD re-bleached palm oil 4 2.78 2.77 RBD re-bleached
and re-deodorized 8 2.77 2.59 @ 140.degree. C. for 60 min
Example 5
Mild Final Bleaching
[0074] Re-bleaching of 150 ml RBD palm oil was carried out using
0.2% Taiko classic G. Bleaching was done for 30 min at 70.degree.
C., 85.degree. C. and 100.degree. C. under vacuum. All filling
steps and filtration was done under atmospheric conditions. Below
table shows the 3-MCPD content data and taste analysis. The
advantage of lower temperature in bleaching on taste could be
demonstrated.
TABLE-US-00006 Re-bleaching temperature [.degree. C.] Taste 3-MCPD
+ Glycidol [ppm] 3-MCPD [ppm] 100.degree. C. 4 2.36 n.m. 85.degree.
C. 6 3.22 n.m. 70.degree. C. 7 5.26 n.m. Standard RBD 9 9.44 2.40
(n.m. = not measured)
Example 6
Bleaching in Oxygen-Poor Environment
[0075] Re-bleaching of 150 ml RBD palm oil was carried out using
0.2% Taiko classic G. Bleaching was done for 1 h at 70.degree. C.
and 85.degree. C., under vacuum. All filling steps and filtration
was done under nitrogen atmosphere. Below table shows the 3-MCPD
content data and taste analysis.
[0076] Under nitrogen atmosphere the results for taste were
significantly better. Even at prolonged bleaching time, the
bleaching did not lower the taste evaluation compared to the RBD
palm oil being tested, while glycidol removal was complete.
TABLE-US-00007 Temperature [.degree. C.] Taste 3-MCPD + Glycidol
[ppm] 3-MCPD [ppm] 85 8 3.63 n.m. 70 8 3.97 n.m. RBD 7 16.7
3.54
Example 7
[0077] At industrial scale, 28 ml RBD Palm oil (deodorized at
270.degree. C.) was chemically interesterified using 0.1% sodium
methoxide as interesterification catalyst. After 1 h reaction at
95.degree. C., catalyst was neutralized with water and washed out.
After bleaching with 0.5% BC at 100.degree. C. and deodorization at
235.degree. C., product was re-bleached and deodorized at
220.degree. C.
TABLE-US-00008 3-MCPD 3-MCPD + Glycidol Sample [ppm] [ppm] Glycidol
[ppm] RBD-Palm Oil 3.22 41.6 25.71 After chemical 0.47 1.28 0.54
interesterification and 1.sup.st bleaching After deodorization 0.63
2.84 1.48 at 235.degree. C. After re-bleaching 0.66 0.67 0.01 After
deodorization 0.64 1.13 0.33 at 220.degree. C.
* * * * *