JP2008247774A - Polyglycerol fatty acid ester having ultra low smell and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultra low smell polyglycerol fatty acid ester widely used as an emulsifying agent even in the fields of a medicine, cosmetic, etc., as well as a food. <P>SOLUTION: A polyglycerol fatty acid ester composition having ≤70 ppb content of 7-10C unsaturated aldehyde and a polyglycerol fatty acid ester composition having ≤100 ppb content of hydroxyacetone are provided. Such polyglycerol fatty acid ester compositions are obtained by bringing a crude polyglycerol fatty acid ester composition in contact with a solvent having ≤3.4 specific permitivity at 25°C for highly purifying. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyglycerin fatty acid ester having a significantly reduced odor level than conventional ones and a method for producing the same.

  Polyglycerin fatty acid ester compositions are widely used in the fields of food, medicine, cosmetics and the like as emulsifiers because of their excellent safety and function. The most common method for producing a polyglycerol fatty acid ester is a method in which polyglycerol and a fatty acid are reacted in the absence of a solvent using sodium hydroxide or the like as a catalyst. However, the polyglycerin fatty acid ester produced by this reaction has a peculiar unpleasant odor, and various deodorizing methods have been studied.

For example, it is known that deodorization is performed by adding water to a polyglycerin fatty acid ester composition and then dehydrating under reduced pressure using a thin film evaporator (see Patent Document 1).
The detection threshold for odorous substances (how much human recognizes as odor) differs for each odorous substance. In general, the detection threshold for hydrocarbons depends on the type of functional group and the length of the hydrocarbon chain. Depends on the situation, and when the hydrocarbon chain is C ₆ , it becomes the lowest feeling. Moreover, the volatility of the odor substance also affects the ease of feeling as an odor. Generally, the shorter the hydrocarbon chain, the higher the volatility and the easier it is to recognize it as an odor. Furthermore, the more hydrophilic substances are easier to remove. Based on this viewpoint, conventionally, as a cause of the odor of the polyglycerol fatty acid ester composition, studies have been made on how to remove substances such as formaldehyde, acetaldehyde, propanal, and hexanal to a low level.
JP 2001-114731 A

  An object of the present invention is to provide a polyglycerol fatty acid ester composition which is highly deodorized and suitable for various uses.

However, the present inventors actually have other important odor substances other than those conventionally considered, and by reducing this, a highly low-brominated polyglycerol fatty acid ester composition can be obtained. We thought that it might be, and intensively studied to solve the above problems. As a result, the polyglycerol fatty acid ester composition having a particularly small content of the specific substance has an ultra-low odor, and the raw material polyglycerol fatty acid ester composition is brought into contact with a solvent having a relative dielectric constant at 20 ° C. of 3.4 or less. It has been found that this ultra-low odor polyglycerol fatty acid ester can be obtained.
That is, the first gist of the present invention resides in a polyglycerol fatty acid ester composition characterized in that the content of C _7-10 unsaturated aldehyde is 70 ppb or less. The second gist of the present invention resides in a polyglycerin fatty acid ester composition characterized in that the content of hydroxyacetone is 100 ppb or less. The third gist of the present invention resides in a polyglycerin fatty acid ester composition characterized in that the ignition residue is 0.1% by weight or less. The fourth gist of the present invention resides in a method for producing a polyglycerin fatty acid ester composition, wherein the crude polyglycerin fatty acid ester composition is contacted with a solvent having a relative dielectric constant of 3.4 or less at 20 ° C. The fifth gist of the present invention resides in a food containing the above-described high-purity polyglycerin fatty acid ester composition.

In the polyglycerol fatty acid ester composition of the present invention, the content of C _7-10 unsaturated aldehyde is 70 ppb or less. Moreover, the polyglycerol fatty acid ester composition of the present invention has a hydroxyacetone content of 100 ppb or less. In the following, an example of production of the highly odor-reduced polyglycerin fatty acid ester composition of the present invention is shown. If the polyglycerin fatty acid ester composition of the present invention can be obtained, the production method is as follows. It is not limited to.
The crude polyglycerol fatty acid ester used as the raw material of the polyglycerol fatty acid ester composition according to the method of the present invention can use a composition containing a polyglycerol fatty acid ester obtained by a usual method. The polyglycerol fatty acid ester is usually synthesized by esterifying polyglycerol and a fatty acid.
As the polyglycerol to be subjected to the esterification reaction, those having an average degree of polymerization of about 2 to 20 are usually used. In particular, in the case of food use, those having an average degree of polymerization of 4 to 12 are preferably used.
As the fatty acid to be used for the esterification reaction, those having about 8 to 22 carbon atoms are usually used. It is preferable that 50% by weight or more of the constituent fatty acid is a fatty acid having 8 to 22 carbon atoms or a condensate thereof. As the fatty acid, a straight-chain fatty acid is usually used, but a branched one such as isostearic acid, a hydroxy compound such as ricinoleic acid or a condensate thereof may be used. Moreover, although saturated fatty acid or unsaturated fatty acid may be used, since the fatty acid is likely to be decomposed, the method of the present invention is considered to be particularly effective with unsaturated fatty acid. Examples of the saturated fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and the like. Examples of unsaturated fatty acids include oleic acid, linoleic acid, erucic acid and the like. One type of fatty acid may be used, or two or more types may be used in combination.
The molar ratio of the fatty acid to the polyglycerol to be subjected to the esterification reaction may be arbitrarily determined according to the HLB of the target polyglycerol fatty acid ester.
The esterification reaction is preferably performed at 200 ° C. or higher in view of the reaction time. On the other hand, it is preferable to carry out at 260 ° C. or lower from the viewpoint of coloring due to side reaction, odor and the like. The reaction is preferably performed in an atmosphere of an inert gas such as nitrogen from the viewpoint of preventing oxidation.

As the esterification catalyst, an alkali metal hydroxide or carbonate such as sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate is usually used. Although the fatty acid alkali metal salt produced by the reaction of the esterification catalyst with the raw fatty acid can be an ignition residue, generally, the less the ignition residue of the polyglycerol fatty acid ester, the less the bitterness may be. Further, when the esterification catalyst is less, side reactions such as hydrolysis and transesterification are less likely to occur during the dehydration operation. The catalyst can be removed from the polyglycerol fatty acid ester by adsorption or the like, but the esterification catalyst is preferably 0.1% by weight or less, particularly preferably 0, based on the total amount of polyglycerol and fatty acid. .01% by weight or less is preferable. By setting the amount of the esterification catalyst to the above upper limit or less, a polyglycerin fatty acid ester having an ignition residue of less than 1.5% by weight, preferably 0.2% by weight or less, more preferably 0.05% by weight or less. Can be easily obtained.
The crude polyglycerin fatty acid ester composition obtained by the above method usually has a peculiar unpleasant odor.

In the method for producing a polyglycerin fatty acid ester composition of the present invention, an odor component is removed by contacting with a solvent having a relative dielectric constant at 20 ° C. of 3.4 or less. The relative dielectric constant is an index of molecular polarity, and is usually measured with an external electric field having a frequency of 1 MHz. Specific values of the dielectric constant are described in Chemical Handbook Rev. 5 II, pages 619-623. The relative dielectric constant (20 ° C.) of the solvent used in the method of the present invention is preferably 3.0 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. The lower limit of the relative dielectric constant (20 ° C.) of the solvent is usually 0.5, preferably 1.0. It is preferable for the relative dielectric constant to be not more than the above upper limit because C _7-9 aldehydes (including unsaturation) can be removed without removing the emulsifier component. Further, when the relative dielectric constant is equal to or higher than the lower limit, hexanal which is a C ₆ aldehyde is easily removed together. Examples of the solvent having a relative dielectric constant (ε) of 3.4 or less include pentane (ε1.8), hexane (ε1.9), heptane (ε1.9), octane (ε1.9), and nonane (ε2.0). ), Decane and the like (ε2.0) saturated hydrocarbons and carbon tetrachloride (ε2.0), benzene (ε2.3), supercritical carbon dioxide (ε1.0 or less), and the like.
Among these, a solvent having a high yield of polyglycerol fatty acid ester is preferable. Here, when the target polyglycerin fatty acid ester is hydrophilic, the polyglycerin fatty acid ester can be obtained in a high yield even if purification is performed with a solvent having a relative dielectric constant of 3.4 or less. However, when the polyglycerol fatty acid ester is hydrophobic, it is particularly preferable to use a solvent containing hexane and a hydroxyl group.
In the case of mass production, since the purity of the solvent affects the relative dielectric constant, it is easier to control the reaction by using a supercritical CO ₂ solvent. For example, in the case of hexane, when recycled hexane is used, since it is often mixed with several weight% of heptane or octane, it is considered that the efficiency of removing impurities by the method of the present invention is affected. Here, for example, hexane having a purity of 99% by weight can be easily obtained at a test tube level. However, using a hexane having a purity of 99% by weight in the case of several tons level is very expensive.
The method of the present invention is preferably further combined with a thin film evaporator treatment. The treatment with the thin film evaporator may be performed before or after the method of the present invention. However, since the thermal decomposition may occur during the treatment with the thin film evaporator, the thin film evaporator treatment is performed before the purification method of the present invention. It is preferable to apply. That is, it is preferable to add water to polyglycerin fatty acid ester to form an aqueous solution, and then dehydrate under reduced pressure using a thin film evaporator, and then perform the above solvent treatment. Specifically, it is preferable to mix the reaction product with water to obtain a homogeneous dispersion solution according to the method described in JP-A No. 2001-114731, and to dehydrate this solution with a thin film evaporator under reduced pressure. Moreover, you may use the process by activated carbon or activated clay etc. together with the purification method of this invention.

For example, a polyglycerol fatty acid ester composition having a C _7-10 unsaturated aldehyde content of 70 ppb or less can be obtained by the above method. Moreover, the polyglycerol fatty acid ester composition whose hydroxyacetone content is 100 ppb or less can be obtained by the above method.
The reason why these substances are contained in the polyglycerin fatty acid ester composition is unknown, but it is not caused by oxidation or thermal decomposition of the fatty acid in the polyglycerin fatty acid ester composition or byproduct from residual glycerin. It is thought that there is not. That is, since the formation reaction of polyglycerin fatty acid ester is usually performed at a high temperature of 200 ° C. or higher, these substances are considered to be generated by a deterioration reaction due to oxidation. Oxidative degradation reactions of fats and oils such as polyglycerin fatty acid esters are thought to occur due to unsaturated parts in the constituent fatty acids, but in general, it is very difficult to control the oxidation in heating reactions of fats and oils. Therefore, it is considered that the odor component found in the present invention is generated.
In general, highly volatile substances have attracted attention as odor components. In the present invention, C7 _~
It is quite surprising that the odor could be reduced by reducing less volatile materials such as ₁₀ unsaturated aldehydes and hydroxyacetone. Moreover, the residual amount of these substances is usually very small compared to the residual amount of components known as odor components. The reason for the extremely low odor when the residual amount of these substances is small is not clear, but the mechanism of the odor is very complicated.For example, if there is a highly volatile odor component, The odor due to these substances is not worrisome, but if the main odor component is reduced, there is a possibility that the component is anxious.
The purity of the polyglycerol fatty acid ester composition of the present invention is usually 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. Moreover, since the purity of the polyglycerol fatty acid ester composition of this invention is so high that it is preferable, the upper limit is 100.00 weight%.
The content of the C _7-10 unsaturated aldehyde in the polyglycerin fatty acid ester composition of the present invention is preferably as low as possible, preferably 70 ppb or less, more preferably 50 ppb or less, and 30 ppb or less. It is particularly preferred. The lower limit is preferably as small as possible, but even if it is lower than the detection limit of 0.1 ppb, it is considered that the human nose cannot be distinguished. The content of the unsaturated aldehyde of the C _{7 to 10} is the total amount of content of the unsaturated aldehyde C _{7 to 10.} Of these, the C ₈ unsaturated aldehyde is preferably 10 ppb or less, and more preferably 7.0 ppb or less. Further, the C ₉ unsaturated aldehyde is preferably 10 ppb or less, and more preferably 7.0 ppb or less.
The content of hydroxyacetone in the polyglycerin fatty acid ester composition of the present invention is preferably as low as possible, preferably 100 ppb or less, more preferably 70 ppb or less, particularly preferably 50 ppb or less, Most preferably, it is 30 ppb or less. The lower limit is preferably as small as possible, but even if it is lower than the detection limit of 0.1 ppb, it is considered that the human nose cannot be distinguished.
Impurities in the polyglycerol fatty acid ester composition of the present invention can be analyzed by gas chromatography-mass spectrometry (GC-MS).

(Gas chromatograph-mass spectrometry measurement method)
Weigh 1.0 g of the sample into a 20 mL headspace vial, then seal it to 6
Heated at 0 ° C. for 60 minutes. The components in the gas phase in the vial were subjected to solid-phase microextraction with fibers coated with an adsorbent. Measured by the GC-MS method, the odor component in the sample was quantified with a calibration curve created using the standard of each component.

Headspace / solid phase microextraction conditions;
Sample amount: 1.0 g
Sample bottle: Chromacol's “headspace vial” (20 mL)
Sample lid: CRS “Magnetic Cap” (Teflon (registered trademark) / silicon septum)
Heating temperature: 60 ° C
Heating time: 60 minutes adsorption phase: “75μm Carboxen / PDMS” manufactured by SUPELCO
GC / MS (EI) measurement condition column: “HP-INNOWAX” (60m • L * 0.25mm • ID, 0.5μm • Df) manufactured by Agilent
Column flow rate: 1.4mL / min (Helium, constant flow)
Inlet temperature: 250 ° C
Desorption conditions: 250 ° C, 8 minutes (at GC Injection)
Injection mode; Splitless
Column temperature: 40 ° C. * 13 min to 10 ° C./min to 250 ° C. * 10 min
Measurement mode: MS (EI Scan-Positive, scan range: m / z = 10-500)

In the highly deodorized polyglycerol fatty acid ester composition of the present invention, it is preferable to use an antioxidant in order to prevent the constituent fatty acids from being oxidatively deteriorated and peroxides generated during storage. . As the antioxidant, dl-α-tocopherol, erythorbic acid, sodium erythorbate and the like may be used in an amount of about 50 to 10,000 ppm, particularly about 100 to 1000 ppm.
Since the polyglycerin fatty acid ester of the present invention has an ultra-low odor, it can be widely used as an emulsifier from foods, pharmaceuticals, cosmetics and the like to various fields of processed oils and fats.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, the sensory test of the samples was performed as follows.

(Sensory test)
A sample of 300 mg was put in a 70 ml glass bottle with a lid, and five monitors A to E evaluated the odor according to the following criteria.
1 point: Very good. No odor is felt.
2 points: Good. The odor is slightly felt, but it is hardly a problem.
3 points: Slightly good. I feel odor but not enough to be worried 4 points: Slightly insufficient. The odor can be sensed reliably and is somewhat uncomfortable.
5 points: Insufficient. Odor is strong and uncomfortable.

(Production example)
1150 parts by weight of polyglycerin (hydroxyl value 888 g KOH / g, average polymerization degree 10) and 360 parts by weight of oleic acid were charged into a reactor equipped with a heating jacket and a stirrer. To this was added 0.36 parts by weight of a 25% by weight aqueous sodium hydroxide solution, and the mixture was heated to 240 ° C. with stirring and reacted for 3 hours. Next, the temperature was raised to 260 ° C., and the reaction was further continued for 4 hours. Polyglycerin fatty acid ester (average composition decaglycerin pentaoleate, saponification value 50.8 mgKOH / g, acid value 0.15 mgKOH / g, ignition residue 0 0.03 wt%) 1120 parts by weight were obtained. The ignition residue is a component remaining after adding sulfuric acid to a sample and igniting it. For example, “ignore residue 0.1 wt% or less” means that sulfuric acid is added to samples 2 to 4 g and 450 to 550 is added.
The residue after ignition at 3 ° C. for 3 hours is 0.1% by weight or less based on the sample amount. Furthermore, specifically, it can be quantified based on the “ignition residue test method” described in the 7th edition of the Food Additives Official Document (Yodogawa Shoten).
2000 parts by weight of water was mixed with 1120 parts by weight of the obtained product and stirred at 70 ° C. to obtain a uniform aqueous solution. This aqueous solution was dehydrated at 110 ° C. under a pressure of 70 Torr using a horizontal Kontro thin film evaporator to obtain a crude polyglycerin fatty acid ester composition.

Example 1
155 parts by weight of the product obtained in the production example was extracted using supercritical fluid carbon dioxide under the conditions of 25 MPa and 60 ° C. until the weight of the extract was 8% by weight of the charged polyglycerol, The residual liquid was obtained as a deodorized product. The ignition residue of the deodorized product was less than 0.1% by weight. Moreover, the result of the sensory test and the analysis result by GC-MS are shown below.
(Comparative Example 1)
The polyglycerol fatty acid ester composition obtained in the production example had a saponification value of 50.8 mgKOH / g and an acid value of 0.13 mgKOH / g. Moreover, the result of the sensory test and the analysis result by GC-MS are shown below.
(Sensory evaluation results)

Claims (9)

The polyglycerol fatty acid ester composition, wherein the content of C _7-10 unsaturated aldehyde is 70 ppb or less.   A polyglycerin fatty acid ester composition, wherein the content of hydroxyacetone is 100 ppb or less.   A polyglycerin fatty acid ester composition, wherein the ignition residue is 0.1% by weight or less.   A method for producing a polyglycerin fatty acid ester composition, comprising: purifying a crude polyglycerin fatty acid ester composition by bringing it into contact with a solvent having a relative dielectric constant at 25 ° C. of 3.4 or less.   5. The method for producing a polyglycerin fatty acid ester composition according to claim 4, wherein the solvent having a relative dielectric constant at 25 ° C. of 3.4 or less is supercritical carbon dioxide. Method. The content of C _7-10 unsaturated aldehyde is 50 by the production method according to claim 4 or 5.
A method for producing a polyglycerin fatty acid ester composition, characterized in that the polyglycerin fatty acid ester composition is reduced to not more than% by weight.   A method for producing a polyglycerin fatty acid ester composition, wherein the content of hydroxyacetone is reduced to 50% by weight or less by the production method according to claim 4 or 5.   A polyglycerin fatty acid ester composition obtained by the production method according to claim 4.   A food containing the polyglycerin fatty acid ester composition according to any one of claims 1 to 3 or 8.