TECHNICAL FIELD
[0001] The present invention relates a method of producing a refined palm-based fat and/or
oil, and a method of reducing glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and/or diglyceride in the refined palm-based fat and/or oil.
BACKGROUND ART
[0002] Fats and/or oils contain trace components which may be implicated in physiology activities.
These trace components include glycidol, 3-chloropropane-1,2-diol, fatty acid esters
thereof, and the like. The above trace components are suspected to be linked with
nutritional problems, but unlikely constitute a direct threat to health as long as
they are in those levels where they are included in fats and/or oils such as plant
oils which have a good track record in ingestion through diets and the like over a
period of many years. In line with this, the tolerable upper intake level and other
standards are not established. However, due to the demands for safer fats and/or oils,
various methods of reducing the aforementioned components in fats and/or oils have
been proposed.
[0003] Glycidol, 3-chloropropane-1,2-diol, and fatty acid esters thereof are known to be
generated during a deodorizing step and other. Moreover, diglyceride is a known agent
responsible for 3-chloropropane-1,2-diol and the like (Nonpatent Document 1). It is
recognized that a high concentration of 3-chloropropane-1,2-diol tends to be present
in diglyceride-rich fats and/or oils, particularly in refined palm-based fats and/or
oils (palm oil, palm kernel oil, and the like). Accordingly, Patent Document 1, for
example, provides a method of reducing glycidol, 3-chloropropane-1,2-diol, fatty acid
esters thereof, and the like in fats and/or oils such as palm oil, the method including:
bleaching a deodorized oil with white clay at a pH of 5 to 7; and further performing
deodorization. Patent Document 2 provides a method of controlling an increase in glycidol
and fatty acid esters thereof, the method including: performing deodorization at a
high temperature and a high vapor amount.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2014-047290
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2013-112761
Non-Patent Document 1: LWT-Food Science and Technology 42(2009)1751-1754
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0004] However, glycidol and the like may not be sufficiently reduced in the deodorizing
step due to prolonged exposure of a fat and/or oil to a high temperature. Therefore,
there have been demands for a method capable of reducing generation of glycidol and
the like in a step other than the deodorizing step.
[0005] The present invention is made in view of the aforementioned circumstances. An object
of the present invention is to provide a method of producing a refined palm-based
fat and/or oil in which the contents of glycidol, 3-chloropropane-1,2-diol, and fatty
acid esters thereof, and/or diglyceride can be reduced.
Means for Solving the Problems
[0006] The present investors found that the above problems can be solved by adjusting a
temperature condition for thin-film distillation treatment in a method of producing
a refined palm-based fat and/or oil including the thin-film distillation treatment.
Then, the present invention has been completed. Specifically, the present invention
can provide the followings.
- (1) A method of producing a refined palm-based fat and/or oil, the method including
a step of performing thin-film distillation treatment of a raw material palm-based
fat and/or oil at a temperature condition of 155°C or more and 290°C or less to obtain
the refined palm-based fat and/or oil, the total amount of glycidol and fatty acid
esters thereof in terms of glycidol in the refined palm-based fat and/or oil being
50% or less of the total amount of glycidol and fatty acid esters thereof in terms
of glycidol in the raw material palm-based fat and/or oil.
- (2) A method of producing a refined palm-based fat and/or oil, the method including
a step of performing thin-film distillation treatment of a raw material palm-based
fat and/or oil of 155°C or more and 290°C or less to obtain the refined palm-based
fat and/or oil,
the total amount of 3-chloropropane-1,2-diol and fatty acid esters thereof in terms
of 3-chloropropane-1,2-diol in the refined palm-based fat and/or oil being 95% or
less of the total amount of 3-chloropropane-1,2-diol and fatty acid esters thereof
in terms of 3-chloropropane-1,2-diol in the raw material palm-based fat and/or oil.
- (3) A method of producing a refined palm-based fat and/or oil, the method including
a step of performing thin-film distillation treatment of a raw material palm-based
fat and/or oil at a temperature condition of 155°C or more and 290°C or less to obtain
the refined palm-based fat and/or oil,
the total amount of diglyceride in the refined palm-based fat and/or oil being 65%
or less of the total amount of diglyceride in the raw material palm-based fat and/or
oil.
- (4) The method of producing a refined palm-based fat and/or oil according to any one
of (1) to (3), wherein the raw material palm-based fat and/or oil is pre-treated through
a deodorizing step.
- (5) The method of producing a refined palm-based fat and/or oil according to any one
of (1) to (4), wherein the degree of vacuum in the thin-film distillation treatment
is 1.0 Pa or less.
- (6) The method of producing a refined palm-based fat and/or oil according to any one
of (1) to (5), wherein the thin-film distillation treatment is short-path distillation
treatment.
- (7) The method of producing a refined palm-based fat and/or oil according to any one
of (1) to (6), wherein the iodine value of the raw material palm-based fat and/or
oil is less than 58.
- (8) A method of reducing glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and/or diglyceride in a refined palm-based fat and/or oil, the method including
performing thin-film distillation treatment of a raw material palm-based fat and/or
oil at a temperature condition of 155°C or more and 290°C or less.
Effects of the Invention
[0007] According to an embodiment of the present invention, provided is a method of producing
a refined palm-based fat and/or oil, in which the contents of glycidol, 3-chloropropane-1,2-diol,
and fatty acid esters thereof, and/or diglyceride can be reduced.
PREFERRED MODE FOR CARRYING OUT THE INVENTION
[0008] Below, the embodiments of the present invention will be described, but the present
invention shall not be limited to the following embodiments.
[0009] The method of produce according to an embodiment of the present invention includes
a step of performing thin-film distillation treatment of a raw material palm-based
fat and/or oil at a temperature condition of 155°C or more and 290°C or less to obtain
a refined palm-based fat and/or oil. Below, the thin-film distillation treatment and
palm-based fats and/or oils used for an embodiment of the present invention will be
described in detail.
[Thin-film distillation treatment]
[0010] According to an embodiment of the present invention, a raw material palm-based fat
and/or oil is subjected to thin-film distillation treatment. The term "thin-film distillation
treatment" as used herein means that a raw material palm-based fat and/or oil is allowed
to form a thin-film, and heated under a reduced pressure to effect evaporation. A
residue (a thin-film distillated fat and/or oil) in which a distillate is separated
from the raw material palm-based fat and/or oil can be obtained through the above
treatment. The distillate may contain fatty acid, monoglyceride, and/or diglyceride,
and the like. The residue may contain triglyceride and the like. The term "refined
palm-based fat and/or oil" as used herein refers to a palm-based fat and/or oil (a
thin-film distillated fat and/or oil) subjected to at least thin-film distillation
treatment.
[0011] After conducting extensive studies, the present investors found that generation of
glycidol, 3-chloropropane-1,2-diol, and fatty acid esters thereof can be reduced by
adjusting a temperature condition to 155°C or more and 290°C or less when thin-film
distillation treatment of a raw material palm-based fat and/or oil is performed. It
is noted that hereinafter "3-chloropropane-1,2-diol" may also be referred to as "3-MCPD."
[0012] The temperature condition for the thin-film distillation treatment in an embodiment
of the present invention corresponds to a temperature at an evaporation surface of
a thin-film distillator. That is, the phase "the temperature condition for thin-film
distillation treatment is 155°C or more and 290°C or less" means that the temperature
at an evaporation surface of a thin-film distillator is 155°C or more and 290°C or
less. For example, the temperature condition for thin-film distillation treatment
corresponds to an evaporator tube temperature when the thin-film distillation treatment
is performed with a short-path distillator.
[0013] A temperature condition of 155°C or more for thin-film distillation treatment can
remove thermally unstable substances, high-boiling point substances, and the like
included in a raw material palm-based fat and/or oil while efficiently suppressing
generation of a trace component such as glycidol, 3-MCPD, and fatty acid esters thereof
in the raw material palm-based fat and/or oil. In view of an improved efficiency of
distillation, the temperature condition for thin-film distillation treatment is preferably
160°C or more, more preferably 190°C or more.
[0014] A temperature condition of 290°C or less for thin-film distillation treatment enables
efficient distillation of a fat and/or oil while suppressing generation of a trace
component such as glycidol, 3-MCPD, and fatty acid esters thereof, which tend to be
generated at a high temperature condition. In view of further reduced generation of
such a trace component, the temperature condition for thin-film distillation treatment
is preferably 270°C or less, more preferably 250°C or less. It is noted that for a
palm-based fat and/or oil rich in unsaturated fatty acid, for example, a palm-based
fat and/or oil having an iodine value of 58 or more, thin-film distillation treatment
may be performed at less than 175°C in order to reduce generation of trans-fatty acid.
[0015] The degree of vacuum in an embodiment of the present invention is preferably close
to 0 (zero) Pa because a trace component such as glycidol, 3-MCPD, and fatty acid
esters thereof; thermally unstable substances; high-boiling point substances; and
the like can be removed more easily. Specifically, the thin-film distillation treatment
in an embodiment of the present invention may be preferably performed under a degree
of vacuum of 1.0 Pa or less, more preferably 0.5 Pa or less, and even more preferably
0.3 Pa or less.
[0016] It is noted that the "degree of vacuum" as used herein is expressed in accordance
with the absolute pressure. The value is expressed relative to the absolute vacuum
which is considered as zero, and represents how close to the ideal vacuum state (the
absolute vacuum).
[0017] The processing time for thin-film distillation treatment refers to a period of time
while a fat and/or oil stays on an evaporation surface of a thin-film distillator.
There is no particular limitation for the processing time, but it may be preferably
1 second or more, more preferably 3 seconds or more in order to effect sufficient
distillation. Further, the processing time for thin-film distillation treatment is
preferably 5 minutes or less, more preferably 3 minutes or less, even more preferably
1 minute or less, and most preferably 30 seconds or less in order to reduce heat effects
on a raw material palm-based fat and/or oil.
[0018] The processing time for thin-film treatment is related to the processing rate for
thin-film treatment. The processing rate for thin-film treatment can be expressed
in terms of the "oil feeding rate per unit area of an evaporation surface." The term
"oil feeding rate per unit area of an evaporation surface" as used herein refers to
a value obtainable by dividing the feeding rate of a raw material palm-based oil/fat
per hour by the area of the evaporation surface. The "oil feeding rate per unit area
of an evaporation surface" in an embodiment of the present invention may be preferably
2.00×10
-3 L/h·cm
2 or more, more preferably 7.00×10
-3 L/cm
2 or more in order to reduce heat effects on a raw material palm-based fat and/or oil.
Further, the "oil feeding rate per unit area of an evaporation surface" may be preferably
12.0×10
-3 L/h·cm
2 or less, more preferably 10.0×10
-3 L/cm
2 or less in order to effect sufficient distillation.
[0019] The types of thin-film distillation include molecular distillation which is performed
under high vacuum (< 0.1 Pa) and in which a condenser is arranged within a distance
shorter than the mean free path of evaporating molecules; and short-path distillation
which is performed at 0.1 Pa or more and in which a condenser is arranged at around
a distance equal to the mean free path of evaporating molecules. The short-path distillation
treatment is preferably performed in an embodiment of the present invention in view
of high efficiency of distillation.
[0020] There is no particular limitation for a thin-film distillator used in thin-film distillation
treatment, but evaporators of falling liquid film, centrifugal, rising liquid film,
wiped film, and the like may be used. Wiped film evaporators are preferred because
the residence time of a raw material palm-based fat and/or oil within a thin-film
distillator can be short enough to reduce heat effects on a raw material palm-based
fat and/or oil. There is no particular limitation for a material of an evaporation
surface of a thin-film distillator, but those made of glass or stainless steel may
be used.
[0021] There is no particular limitation for the timing to perform thin-film distillation
treatment in a refinement step of a palm-based fat and/or oil.
[0022] As described below, a raw material palm-based fat and/or oil may be pre-treated through
a refinement step other than thin-film distillation treatment, or unrefined. A raw
material palm-based fat and/or oil pre-treated through a deodorizing step is preferred
because the contents of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and diglyceride can be reduced more easily by thin-film distillation treatment.
A raw material palm-based fat and/or oil without pre-treatment in a deodorizing step
may also be used. In this case, the content of diglyceride may be reduced more easily
by thin-film distillation treatment, and a deodorizing step may be then performed
after the thin-film distillation treatment to effect more efficient reduction of the
contents of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters thereof.
[0023] For a raw material palm-based fat and/or oil pre-treated through a refinement step
other than thin-film distillation treatment, thin-film distillation treatment may
be performed at any timing after the respective refinement step (one or more of a
degumming step, a deacidifying step, a water-washing step, a bleaching step, a deodorizing
step, a fractionating step, and the like). The resulting fat and/or oil obtained after
thin-film distillation treatment may be directly distributed as a refined palm-based
fat and/or oil, or may be subjected to an additional refinement step. For example,
when the raw material palm-based fat and/or oil is a palm-based fat and/or oil obtained
through a deodorizing step and the like, the palm-based fat and/or oil may be subjected
to a fractionating step after thin-film distillation treatment.
[0024] When the raw material palm-based fat and/or oil is an unrefined palm-based fat and/or
oil, the resulting fat and/or oil after thin-film distillation treatment may be directly
distributed as a refined palm-based fat and/or oil, or may be subjected to an additional
refinement step.
[0025] There is no particular limitation for the conditions for each refinement step (a
degumming step, a deacidifying step, a water-washing step, a bleaching step, a deodorizing
step, a fractionating step, and the like) other than thin-film distillation treatment,
but conditions commonly used in refinement of fats and/or oils may be used.
[Raw material palm-based fat and/or oil]
[0026] Palm-based fats and/or oils use for an embodiment the present invention include fats
and/or oils from palm. Specifically, palm-based fats and/or oils include, for example,
palm oil, palm kernel oil, fractionated oils of palm oil, fractionated oils of palm
kernel oil, hydrogenated oils of palm oil, hydrogenated oils of palm kernel oil, hydrogenated
oils of fractionated oils of palm oil, hydrogenated oils of fractionated oils of palm
kernel oil, and transesterified oils thereof, and the like. It is noted that fractionated
oils of palm oil include super olein, palm olein, palm mid fraction, and palm stearin.
Fractionated oils of palm kernel oil include palm kernel olein and palm kernel stearin.
[0027] There is no particular limitation for the raw material palm-based fat and/or oil
to be subjected to the aforementioned thin-film distillation treatment, but palm-based
fats and/or oils may be used which are pre-treated through a refinement step (a degumming
step, a deacidifying step, a water-washing step, a bleaching step, a deodorizing step,
a fractionating step, and/or the like) other than thin-film distillation treatment,
or unrefined palm-based fats and/or oils may be used. As described above, the raw
material palm-based fat and/or oil is preferably a palm-based fat and/or oil pre-treated
through a deodorizing step. There is no particular limitation for the method of refining
a fat and/or oil, but it may be either chemical refinement (chemical refining) or
physical refinement (physical refining). It is noted that in the former chemical refinement,
a crude oil obtained by squeezing/extracting plant as a raw material is refined by
performing degumming treatment, alkali deacidification treatment, bleaching treatment,
dewaxing treatment, deodorizing treatment to obtain a refined fat and/or oil. In contrast,
in the latter physical refinement, a crude oil is refined by performing degumming
treatment, non-alkali deacidification treatment such as distillation, bleaching treatment,
deodorizing treatment to obtain a refined fat and/or oil. It is noted that a fat and/or
oil pre-treated through a degumming step, a bleaching step, a deodorizing step is
called an RBD (Refined Bleached Deodorized) oil.
[0028] There is no particular limitation for the properties of a raw material palm-based
fat and/or oil, but the iodine value is preferably less than 58 in view of having
less unsaturated fatty acids, less generation of trans-fatty acids, and high oxidation
stability.
[0029] The main component of a raw material palm-based fat and/or oil is glyceride, and
other components, for example, plant sterol, lecithin, antioxidant components (tocopherol
and the like), coloring components and the like may be contained.
[Determination of contents of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and diglyceride in refined palm-based fat and/or oil]
[0030] The method of produce according to an embodiment of the present invention can provide
a refined palm-based fat and/or oil having reduced contents of glycidol, 3-chloropropane-1,2-diol,
and fatty acid esters thereof, and diglyceride.
[0031] Specifically, in the method of produce according to an embodiment of the present
invention, the total amount of glycidol and fatty acid esters thereof (in terms of
glycidol) in a refined palm-based fat and/or oil can be reduced to 50% or less, more
preferably 35% or less, and more preferably 20% or less of the total amount of glycidol
and fatty acid esters thereof (in terms of glycidol) in a raw material palm-based
fat and/or oil. Further, the total amount of 3-chloropropane-1,2-diol and fatty acid
esters thereof (in terms of 3-chloropropane-1,2-diol) in a refined palm-based fat
and/or oil can be reduced to 95% or less, more preferably 90% or less, and more preferably
60% or less of the total amount of 3-chloropropane-1,2-diol and fatty acid esters
thereof (in terms of 3-chloropropane-1,2-diol) in a raw material palm-based fat and/or
oil. Moreover, the total amount of diglyceride in a refined palm-based fat and/or
oil can be reduced to 65% or less, preferably 50% or less, and more preferably 45%
or less of the total amount of diglyceride in a raw material palm-based fat and/or
oil.
[0032] Furthermore, in the method of produce according to an embodiment of the present invention,
the acid value, peroxide value of a refined palm-based fat and/or oil can also be
reduced. Therefore, the method of produce according to an embodiment of the present
invention can provide a highly refined fat and/or oil.
[0033] Still further, in the method of produce according to an embodiment of the present
invention, significant coloring of a refined palm-based fat and/or oil can be prevented.
The color value (a value computed in accordance with the method described below in
Examples) of a refined palm-based fat and/or oil obtained by the method of produce
according to an embodiment of the present invention preferably differs from that of
a raw material palm-based fat and/or oil by ±2 and more preferably by ±1, and even
more preferably it is substantially the same as that of a raw material palm-based
fat and/or oil.
[0034] The contents of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters thereof,
and diglyceride in a fat and/or oil as well as the acid value, peroxide value, and
color value thereof may be determined according to the methods described in Examples.
EXAMPLES
[0035] Below, the present invention will be described specifically with reference to Examples,
but the present invention shall not be limited to these Examples.
<Examples 1 to 4>
[0036] A raw material palm-based fat and/or oil (RBD palm oil, iodine value = 52) was introduced
to an evaporation surface of a short-path distillator Model KDL5 (UIC GmbH; glass
evaporation surface: 480 cm
2; condensation surface: 650 cm
2; maximum flow rate: 1 L/hr), and thin-film distillation treatment (in this example,
short-path distillation treatment) was performed under the conditions shown in Table
1. It is noted that the residence time (that is, the processing time of thin-film
distillation treatment) of the raw material palm-based fat and/or oil on the evaporation
surface of the short-path distillator was set in the range from 5 seconds to 30 seconds.
[0037] A residue and distillate obtained after performing the short-path distillation treatment
under the above conditions were withdrawn. It is noted that the "operation time" in
Table 1 refers to the total operation time of the short-path distillator. The term
"distillate percentage" refers to a percentage of a distillate over the total amount
of the residue and distillate withdrawn. The term "residue percentage" refers to a
percentage of a residue over the total amount of the residue and distillate withdrawn.
[Table 1]
Table 1 |
|
Example 1 |
Example 2 |
Example 3 |
Example 4 |
Operation time (minutes) |
65 |
65 |
65 |
65 |
Evaporation tube temperature (°C) |
160 |
200 |
225 |
250 |
Internal condenser temperature (°C) |
45 |
45 |
45 |
50 |
Degree of vacuum (Pa) |
6.0 |
0.1 |
0.1 |
0.1 |
Distillate percentage (% by mass) |
0.2 |
0.3 |
2.3 |
8.9 |
Residue percentage (% by mass) |
99.8 |
99.7 |
97.7 |
91.1 |
Cold trap (% by mass) |
0.0 |
0.0 |
0.0 |
0.0 |
Feeding rate (g/h) |
495.3 |
507.0 |
503.4 |
512.1 |
[0038] The raw material palm-based fat and/or oil before the short-path distillation treatment,
and the residues after the short-path distillation treatment (which correspond to
a refined palm-based fat and/or oil) were investigated for their physical properties
and compositions.
[0039] The results are shown in Table 2.
[Quantification of MCPD-FS]
[0040] The total amount of 3-MCPD, glycidol, and fatty acid esters thereof in terms of 3-MCPD
(the above total amount is referred to as "MCPD-FS") in each refined fat and/or oil
was quantified in accordance with the German official method (DGF Standard Methods
C-III 18 (09)).
[0041] Specifically, 50 µL of an internal standard (a 20 µg/mL solution of 3-MCPD-d5) was
added to 100 mg of each refined fat and/or oil, and then 1 mL of a sodium methoxide
solution (0.5 mol/L methanol) was added. The reaction was allowed at room temperature
for saponification decomposition. To this, 3 mL of brine (20%) having a trace amount
of acetic acid and 3 mL of hexane were then added and mixed. Subsequently, hexane
was removed. This was then derivatized with 250 µL of aqueous phenylboric acid (25%),
and extracted with 2 mL of hexane, and then measured with an instrument for gas chromatography-mass
spectrometry. A chromatogram obtained from the above measurement with an instrument
for gas chromatography-mass spectrometry was used to compare the ionic strength of
3-MCPD with that of the internal standard 3-MCPD-d5. Then the total amount of 3-MCPD,
glycidol, and fatty acid esters thereof in a fat and/or oil was computed in terms
of free 3-MCPD.
[Quantification of true MCPD]
[0042] The total amount of 3-MCPD and fatty acid esters of 3-MCPD in terms of 3-MCPD (the
above total amount is referred to as "True MCPD") in each refined fat and/or oil was
quantified in accordance with the German official method (DGF Standard Methods C-III
18 (09)).
[0043] Specifically, 50 µL of an internal standard (a 20 µg/mL solution of 3-MCPD-d5) was
added to 100 mg of each refined fat and/or oil, and then 1 mL of a sodium methoxide
solution (0.5 mol/L methanol) was added. The reaction was allowed at room temperature
for saponification decomposition. To this, 3 mL of aqueous sodium bromide (50%) having
a trace amount of acetic acid and 3 mL of hexane were then added and mixed. Subsequently,
hexane was removed. This was then derivatized with 500 µL of aqueous phenylboric acid
(12.5%), and extracted with 2 mL of hexane, and then measured with an instrument for
gas chromatography-mass spectrometry. A chromatogram obtained from the above measurement
with an instrument for gas chromatography-mass spectrometry was used to compare the
ionic strength of 3-MCPD with that of the internal standard 3-MCPD-d5. Then the total
amount of 3-MCPD and fatty acid esters of 3-MCPD in a glyceride composition was computed
in terms of free 3-MCPD.
[0044] It is noted that the numerical values in the parentheses under the item "True MCPD"
in the table below represent the percentage of True MCPD in each refined palm-based
fat and/or oil relative to True MCPD in a raw material palm-based fat and/or oil.
For example, with reference to Example 1, True MCPD in a refined palm-based fat and/or
oil (3.2 mg/kg) is about 94.1% relative to True MCPD in a raw material palm-based
fat and/or oil (3.4 mg/kg).
[Calculation of amount of glycidol]
[0045] Using the values for MCPD-FS and True MCPD determined according to the above method,
the amount of glycidol in each refined fat and oil (the total amount of glycidol and
fatty acid esters thereof in terms of glycidol) was computed based on the following
formula.

wherein "0.67" is a value obtained by dividing the molecular weight (74.1) of glycidol
by the molecular weight (110.54) of 3-MCPD.
[0046] It is noted that the numerical values in the parentheses under the item "glycidol"
in the table below represent the percentage of the amount of glycidol in each refined
palm-based fat and/or oil relative to the amount of glycidol in a raw material palm-based
fat and/or oil. For example, with reference to Example 1, the amount of glycidol in
a refined palm-based fat and/or oil (0.2 mg/kg) is about 33.3% relative to the amount
of glycidol in a raw material palm-based fat and/or oil (0.6 mg/kg).
[Acid value]
[Peroxide value]
[Quantification of amount of diglyceride]
[0049] Measurement was performed in accordance with AOCS "Official Method Cd 11b-91, Determination
of Mono- and Diglycerides by Capillary Gas Chromatography."
[0050] It is noted that the numerical values in the parentheses under the item "diglyceride"
in the table below represent the percentage of the amount of diglyceride in each refined
palm-based fat and/or oil relative to the amount of diglyceride in a raw material
palm-based fat and/or oil. For example, with reference to Example 1, the amount of
diglyceride in a refined palm-based fat and/or oil (7.5 mass%) is about 94.9% relative
to the amount of diglyceride in a raw material palm-based fat and/or oil (7.9 mass%).
[Table 2]
Table 2 |
|
Raw material palm oil |
Example 1 |
Example 2 |
Example 3 |
Example 4 |
MCPD-FS (mg/kg) |
4.3 |
3.5 |
3.0 |
1.9 |
0.8 |
True MCPD (mg/kg) |
3.4 |
3.2 (94.1) |
2.8 (82.4) |
1.7 (50) |
0.7 (20.6) |
Glycidol (mg/kg) |
0.6 |
0.2 (33.3) |
0.1 (16.7) |
0.1 (16.7) |
0.1 (16.7) |
Acid value |
0.06 |
0.03 |
0.02 |
0.03 |
0.02 |
Peroxide value |
0.4 |
0.3 |
0.2 |
0.2 |
0.1 |
Diglyceride (% by mass) |
7.9 |
7.5 (94.9) |
7.0 (88.6) |
5.1 (64.6) |
3.3 (41.8) |
[0051] As shown in Table 2, the method of produce according to an embodiment of the present
invention can reduce values of all of MCPD-FS, True MCPD, glycidol, and diglyceride,
and thus can reduce the amounts of glycidol, 3-chloropropane-1,2-diol, and fatty acid
ester thereof, and diglyceride in a palm-based fat and/or oil.
[0052] The method of produce according to an embodiment of the present invention was also
able to reduce the acid values and the peroxide value.
<Examples 5 to 9>
[0053] The following treatment was performed using a short-path distillator Model KD6 (UIC
GmbH; stainless-steel evaporation surface; 600 cm
2; condensation surface: 600 cm
2; maximum flow rate: 14 L/hr) instead of the short-path distillator Model KDL5 used
in Examples 1 to 4. A raw material palm-based fat and/or oil (an RBD palm oil, iodine
value = 52) was introduced to an evaporation surface of the short-path distillator
Model KD6, and thin-film distillation treatment (in this example, short-path distillation
treatment) was performed under the conditions shown in Table 3. Specifically, the
short-path distillation treatment was performed at a temperature of an evaporation
tube of 270°C and at an altered feeding rate of the raw material palm-based fat and/or
oil. It is noted that the "oil feeding rate per unit area of an evaporation surface"
in Table 3 represents a value obtained by dividing the feeding rate of the raw material
palm-based fat and/or oil per hour by the area (in this example, 600 cm
2) of the evaporation surface.
[Table 3]
Table 3 |
|
Example 5 |
Example 6 |
Example 7 |
Example 8 |
Example 9 |
Evaporation tube temperature (°C) |
270 |
270 |
270 |
270 |
270 |
Internal condenser temperature (°C) |
60 |
60 |
60 |
60 |
60 |
Degree of vacuum (Pa) |
0.01 |
0.01 |
0.01 |
0.10 |
0.31 |
Distillate percentage (% by mass) |
36.8 |
13.2 |
10.7 |
5.8 |
4.3 |
Residue percentage (% by mass) |
63.2 |
86.8 |
89.3 |
94.2 |
95.7 |
Oil feeding rate per unit area of an evaporation surface (×10-3L/h▪cm2) |
2.40 |
6.00 |
7.20 |
9.60 |
11.5 |
[0054] The raw material palm-based fat and/or oil before the short-path distillation treatment,
and the residues after the short-path distillation treatment from Examples 5 to 9
(which correspond to a refined palm-based fat and/or oil) were investigated for their
physical properties and compositions as in Examples 1 to 4. Further, the raw material
palm-based fat and/or oil before the short-path distillation treatment, and the residues
after the short-path distillation treatment ware measured for chromaticity as described
below to compute their color values. The results are shown in Table 4.
[Calculation of color value]
[0055] Chromaticity (Y value, R value) was measured in accordance with "
Standard Methods for the Analysis of Fats, Oils and Related Materials 2.2.1-1996:
Lovibond method," Japan Oil Chemists' Society Ed, and the obtained chromaticity was used to compute a color value (a value of Y +
10R). A Lovibond colorimeter (cell length: 133.4 mm) was used for the measurement.
[Table 4]
Table 4 |
|
Raw material palm-based fat and/or oil |
Example 5 |
Example 6 |
Example 7 |
Example 8 |
Example 9 |
MCPD-FS (mg/kg) |
3.1 |
0.3 |
0.7 |
0.8 |
1.1 |
1.4 |
True MCPD (mg/kg) |
2.2 |
0.1 (4.5) |
0.5 (22.7) |
0.6 (27.3) |
0.9 (40.9) |
1.1 (50.0) |
Glycidol (mg/kg) |
0.6 |
0.1 (16.7) |
0.1 (16.7) |
0.1 (16.7) |
0.1 (16.7) |
0.2 (33.3) |
Acid value |
0.05 |
0.02 |
0.02 |
0.02 |
0.02 |
0.02 |
Diglyceride (% by mass) |
7.2 |
2.6 (36.1) |
4.1 (56.9) |
2.9 (40.3) |
3.8 (52.7) |
6.3 (87.5) |
Color value |
28 |
48 |
32 |
30 |
30 |
30 |
[0056] Table 4 shows that similarly to the results from Examples 1 to 4, values of all of
MCPD-FS, True MCPD, glycidol, and diglyceride can also be reduced in Examples 5 to
9, and thus the amounts of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and diglyceride in a palm-based fat and/or oil can be reduced.
<Examples 10 to 13>
[0057] The following treatment was performed as in Examples 5 to 9 using a short-path distillator
Model KD6. A raw material palm-based fat and/or oil (an RBD palm oil, iodine value
52) was introduced to an evaporation surface of the short-path distillator Model KD6,
and thin-film distillation treatment (in this example, short-path distillation treatment)
was performed under the conditions shown in Table 5. Specifically, the short-path
distillation treatment was performed at a "feeding rate per unit area of an evaporation
surface" of 7.20×10
-3 L/h·cm
2 and at an altered temperature of an evaporation tube.
[Table 5]
Table 5 |
|
Example 10 |
Example 11 |
Example 12 |
Example 13 |
Evaporation tube temperature (°C) |
210 |
230 |
250 |
290 |
Internal condenser temperature (°C) |
60 |
60 |
60 |
60 |
Degree of vacuum (Pa) |
0.01 |
0.01 |
0.01 |
0.02 |
Distillate percentage (% by mass) |
0 |
1.4 |
3.2 |
31.6 |
Residue percentage (% by mass) |
100 |
98.6 |
96.8 |
68.4 |
Oil feeding rate per unit area of an evaporation surface (×10-3L/h▪cm2) |
7.20 |
7.20 |
7.20 |
7.20 |
[0058] The raw material palm-based fat and/or oil before the short-path distillation treatment,
and the residues after the short-path distillation treatment from Examples 10 to 13
(which correspond to a refined palm-based fat and/or oil) were investigated for their
physical properties (including color values) and compositions as in Examples 5 to
9. The results are shown in Table 6.
[Table 6]
Table 6 |
|
Raw material palm oil |
Example 10 |
Example 11 |
Example 12 |
Example 13 |
MCPD-FS (mg/kg) |
3.1 |
2.1 |
1.9 |
1.3 |
0.5 |
True MCPD (mg/kg) |
2.2 |
1.9 (86.4) |
1.5 (68.2) |
1.1 (50.0) |
0.4 (18.2) |
Glycidol (mg/kg) |
0.6 |
0.1 (16.7) |
0.1 (16.7) |
0.1 (16.7) |
0.1 (16.7) |
Acid value |
0.05 |
0.03 |
0.02 |
0.02 |
0.02 |
Diglyceride (% by mass) |
7.2 |
7.0 (97.2) |
6.1 (84.7) |
4.8 (66.7) |
1.9 (26.4) |
Color value |
28 |
28 |
26 |
28 |
38 |
[0059] Table 6 shows that similarly to the results from Examples 1 to 9, values of all of
MCPD-FS, True MCPD, glycidol, and diglyceride can also be reduced in Examples 10 to
13, and thus the amounts of glycidol, 3-chloropropane-1,2-diol, and fatty acid esters
thereof, and diglyceride in a palm-based fat and/or oil can be reduced.