JP4106831B2 - Polyglycerin fatty acid ester and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyglycerin fatty acid ester used as a food emulsifier. The polyglycerin fatty acid ester according to the present invention is typically highly deodorized to such an extent that almost no odor is felt, so it is also suitable for applications in which its use has been limited so far in terms of odor. Can be used.
[0002]
[Prior art]
Polyglycerin fatty acid esters are widely used in the fields of foods, pharmaceuticals, 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. In this method, since the reaction is performed at a high temperature of 200 ° C. or higher, various by-products are mixed in the reaction product and there is a peculiar unpleasant odor. Therefore, various methods for deodorizing polyglycerol fatty acid esters have been studied. In general, it is known that vacuum distillation or steam distillation is effective as a method for deodorizing a liquid substance having a high boiling point, and these methods are used for deodorizing fats and oils.
[0003]
[Problems to be solved by the invention]
However, when these methods are applied to a polyglycerin fatty acid ester among emulsifiers, the foaming is intense and operation is difficult, and there is a possibility that the polyglycerin fatty acid ester is altered by heat. Therefore, the commercially available polyglycerin fatty acid ester is the reaction product obtained by the esterification reaction, or a product obtained by subjecting it to a slight deodorization treatment. Is limited. Accordingly, the present invention is intended to provide a polyglycerol fatty acid ester which is highly deodorized and can be suitably used for various applications.
[0004]
[Means for Solving the Problems]
The present inventors have found that deodorization can be carried out to a very high degree by adding water to polyglycerin fatty acid ester and dehydrating it under reduced pressure using a thin film evaporator. As a result of analyzing the impurities of this deodorized polyglycerin fatty acid ester, it was found that this gave a specific chromatogram by gas chromatography / mass spectrometry (GC / MS), and the present invention was completed. did.
[0005]
That is, the polyglycerin fatty acid ester according to the present invention is obtained by reacting polyglycerin with a fatty acid at a temperature of 200 ° C. or higher in the presence of an alkali catalyst at a weight of 0.5-5. Polyglycerin fatty acid ester obtained by mixing water by weight with water and evaporating and dehydrating the mixture under a reduced pressure of 10 to 150 Torr using a thin film evaporator, which was obtained by gas chromatography / mass spectrometry (GC / MS ), N-caproic acid is detected from the retention time at which 2,3-butanedione is detected when measurement is performed so that phenyl acetate is detected at a retention time of 25.8 to 26.8 minutes under the following conditions: Ratio of the total area (a) of the peaks other than the phenyl acetate peak to the area (b) of the phenyl acetate peak (a / b) But 3.0 or less, preferably characterized in that 2.0 or less.
[0006]
Analysis conditions;
Pretreatment conditions Headspace SPME
Container; Headspace vial, 10ml 22x45mm (Perkin Elmer compatible)
Sample: Polyglycerol fatty acid ester sample amount in which a hexane solution of phenylacetate 2500 μg / ml was added to 10 ppm as phenyl acetate; 0.5 g
Adsorption phase: with liquid phase Fused silica fiber (Suberco)
50 / 30μm DVB / CAR / PDMS
Extraction conditions: 80 ° C. × 30 minutes, vapor phase desorption conditions: 5 minutes, 250 ° C. (gas chromatograph inlet)
GC / MS measurement condition column; HP-FFAP (50 m × 0.32 mm ID, Df = 0.52 μm)
Or separation column column temperature having equivalent resolution; 40 to 240 ° C. (5 min hold → 5 ° C./min temperature rise)
Injection temperature: 250 ° C
Injection method; splitless, 6 minutes ionization method; EI, 50-70 eV
Ion chamber temperature: 150 ° C
Measurement mode: Scan measurement, measurement mass range Mass number m / z = 35-300
GC / MS interface temperature; 240 ° C
Carrier gas; He
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The highly deodorized polyglycerin fatty acid ester according to the present invention is produced by esterifying polyglycerin and a fatty acid by a conventional method, and then adding water to form an aqueous solution. And can be produced by dehydration under reduced pressure. As the polyglycerin used for the esterification reaction, those having an average degree of polymerization of about 3 to 20 are usually used. Among them, it is preferable to use those having a proven average polymerization degree of 4 to 12 for food use. As the fatty acid, those having about 8 to 22 carbon atoms are usually used. As the fatty acid, a straight chain is usually used, but if desired, a branched chain such as isostearic acid, a hydroxy fatty acid such as ricinoleic acid, or a condensate thereof may be used. Examples of some commonly used fatty acids include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid, and unsaturated fatty acids such as oleic acid, linoleic acid and erucic acid. Two or more fatty acids may be used in combination. In general, polyglycerol fatty acid esters having a high proportion of unsaturated fatty acids in the constituent fatty acids have a strong odor. Therefore, in polyglycerol fatty acid esters in which the proportion of unsaturated fatty acids in the constituent fatty acids is 50% by weight or more, particularly 80% by weight or more, The effect of the invention is noticeable.
[0008]
The molar ratio of the fatty acid to the polyglycerol to be subjected to the reaction can be arbitrarily determined according to the HLB of the target polyglycerol fatty acid ester. The esterification reaction is preferably performed at 200 to 260 ° C. When the reaction temperature is lower than this, the reaction takes a long time. On the other hand, if the reaction temperature is higher than this, the side reaction becomes active, the product becomes intensely colored, and the odor becomes strong. The reaction is preferably carried out in an inert gas atmosphere such as nitrogen in order to prevent oxidation.
[0009]
As the esterification catalyst, an alkali metal hydroxide or carbonate such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and the like may be used. These catalysts remain in the polyglycerin fatty acid ester of the product unless removed from the reaction product by adsorption or the like. Therefore, the ignition residue of the polyglycerin fatty acid ester of the product is 1.5% by weight, which is the allowable upper limit. Use not to exceed. Alkali catalysts react with raw fatty acids during the reaction to produce fatty acid alkali metal salts, so if added in large amounts, the results of sensory testing of the product will be reduced, and side reactions such as hydrolysis and transesterification will occur during the dehydration operation. May be caused. In general, since the polyglycerin fatty acid ester is functionally superior when it has a lower ignition residue, the alkali catalyst is used with respect to the total amount of polyglycerin and fatty acid so that such a polyglycerin fatty acid ester is formed. The amount added is preferably 0.1% by weight or less, particularly preferably 0.01% by weight or less. By limiting the addition amount of the alkali catalyst to such a small amount, a polyglycerin fatty acid ester having an ignition residue of 0.1% by weight or less, preferably 0.05% by weight or less can be easily obtained.
[0010]
The reaction product obtained by the above reaction from polyglycerol and fatty acid has a characteristic unpleasant odor. This odor is mainly generated by oxidation or thermal decomposition of fatty acids, and typical examples thereof include aldehydes having 4 to 9 carbon atoms, ketones, carboxylic acids and alcohols. Moreover, C3 alcohols and diols by-produced from residual glycerin in polyglycerin may be contained.
[0011]
In this invention, an odor component is removed from this reaction product, and it is set as the highly functional deodorized polyglycerol fatty acid ester. Deodorization is based on the method described in Japanese Patent Application No. 10-10483, by mixing the reaction product with water to disperse and dissolve it into a uniform aqueous solution, and dehydrating this aqueous solution with a thin film evaporator under reduced pressure. Is preferred. In this method, water is first mixed with the reaction product solution to prepare a uniform aqueous solution. The amount of water mixed is suitably 0.5 to 5 times the weight of the reaction product solution. If the amount of water is less than 0.5 times by weight, a sufficient deodorizing effect cannot be obtained. Generally, the deodorizing effect is improved as the amount of water to be mixed is increased. However, the improvement in the effect becomes smaller as the amount of water increases, and reaches a peak at about 5 times the weight. When the deodorizing effect and the cost required for dehydration are combined, the amount of water mixed is preferably 1 to 3 times the weight of the reaction product liquid.
[0012]
The aqueous solution of the produced reaction product liquid is dehydrated under reduced pressure using a thin film evaporator to obtain the highly deodorized polyglycerol fatty acid ester according to the present invention. Thin film evaporators are most suitable for industrial production of the highly deodorized polyglycerol fatty acid esters according to the present invention rather than using other evaporators. As the thin film evaporator, it is preferable to use a thin film evaporator that forms a thin film of the liquid to be treated on the tube wall by centrifugal force or a rotating blade. As such a type of thin film evaporator, there are known a Smith type, a Sambay type, a Luwa type, a Kontro type, etc. Among them, it is preferable to use a Kontro type. Since this thin film evaporator continuously forms a uniform thin film with a rotor blade, it can be used for liquids with various physical properties. Even if it is easy to foam when dehydrated under reduced pressure, such as polyglycerin fatty acid ester, it is an industrial scale. Can be processed continuously. And since a dehydration process is completed in a short time, even if it is an unsaturated fatty acid type polyglyceryl fatty acid ester whose heat stability is comparatively inferior, it can dehydrate without deteriorating a physical property. Dehydration may be performed according to the amount of water allowed for the product, but is usually performed so that the amount of water in the product is 1.0% by weight or less.
[0013]
The dehydration is preferably performed under a pressure of 10 to 150 Torr, particularly 20 to 100 Torr. Under a pressure lower than 10 Torr, foaming becomes severe and dehydration is difficult. Further, the odor component may not be sufficiently removed under a pressure exceeding 150 Torr. The dehydration temperature is preferably such that the temperature of the polyglycerin fatty acid ester at the outlet of the thin film evaporator is 120 ° C. or lower, particularly 70 to 110 ° C. At high temperatures exceeding 120 ° C., there is a high risk of side reactions such as product coloring and hydrolysis. Conversely, dehydration is significantly slow at low temperatures, such as below 70 ° C. In particular, in a polyglycerin fatty acid ester having a high melting point containing palmitic acid, stearic acid, behenic acid or the like as a constituent fatty acid, the fluidity is remarkably lowered and the dehydration treatment is inhibited.
[0014]
It is preferable to add an antioxidant to the highly deodorized polyglycerin fatty acid ester according to the present invention in order to prevent oxidative degradation of the constituent fatty acids and formation of peroxides during storage. As an antioxidant, dl-α-tocopherol, erythorbic acid, sodium erythorbate and the like may be added in an amount of about 50 to 10,000 ppm, particularly about 100 to 1000 ppm.
[0015]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
In the following examples, sample sensory tests and gas chromatograph / mass spectrometry analysis were performed as follows.
[0016]
Sensory test;
Place 30 g of sample in a 100 ml glass bottle with a lid, cover and store in a thermostatic bath at 50 ° C. for 30 minutes. Subsequently, it took out from the thermostat, opened the lid, and five panelists evaluated the odor according to the following criteria.
A: Very good. The odor is hardly felt.
○: Good. The odor is slightly felt, but it is hardly a problem.
Δ: Slightly insufficient. The odor can be sensed reliably and is somewhat uncomfortable.
X: Insufficient. Odor is strong and uncomfortable.
[0017]
Gas chromatograph / mass spectrometry measurement method;
In a headspace vial, 0.5 g of a polyglycerol fatty acid ester added with a hexane solution of phenyl acetate in a concentration of 2500 μg / ml so as to be 10 ppm as phenyl acetate is adsorbed and the vaporized components are adsorbed. The obtained sample was measured by GC / MS. From the retention time (6.5 minutes) at which 2,3-butanedione was eluted in the obtained total ion chromatogram, the retention time (36 minutes) at which n-caproic acid was eluted. The peak area ratio (a / b) was determined by dividing the total peak area (a) excluding the phenyl acetate peak by the peak area (b) of phenyl acetate from the peaks detected during
[0018]
Pretreatment conditions Headspace SPME
Container; Headspace vial, 10 ml, 22 x 45 mm (Perkin Elmer compatible)
Sample amount; 0.5g
Adsorption phase: with liquid phase Fused silica fiber 50/30 μm, DVB / CAR / PDMS (manufactured by Suberco)
Extraction conditions; 80 ° C. × 30 minutes desorption conditions; 250 ° C. for 5 minutes (GC inlet)
GC / MS measurement condition equipment: GC HP-5890
MS JEOL AX-500
Separation column; HP-FFAP (50 m × 0.32 mm ID, Df = 0.52 μm)
Column temperature: held at 40 ° C. for 5 minutes and then heated to 240 ° C. at a rate of 5 ° C./min. Inlet 250 ° C
Ion chamber temperature: 150 ° C
GC / MS interface temperature; 240 ° C
Carrier gas; He 15 psi
Ionization mode; EI, 70 eV
Scan range; mass number m / z = 35-300
Injection method; splitless [0019]
Example 1
350 parts by weight of polyglycerin (hydroxyl value 888 mgKOH / g, average polymerization degree 10) and 650 parts by weight of oleic acid were charged into a reactor equipped with a heating jacket and a stirrer. After adding 0.1 parts by weight of 25% by weight aqueous sodium hydroxide solution, the mixture was heated to 240 ° C. with stirring and reacted for 3 hours. Next, the temperature was raised to 260 ° C., and the mixture was further reacted for 4 hours. Polyglycerin fatty acid ester (average composition decaglycerin pentaoleate, saponification value 137 mgKOH / g, acid value 0.20 mgKOH / g, ignition residue 0.01 wt. %) 958 parts by weight were obtained.
1000 parts by weight of water was mixed with 500 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 deodorized polyglycerol fatty acid ester (saponification value 137 mgKOH / g, acid value 0.25 mgKOH / g). . Table 1 shows the results of the sensory test of the non-deodorized product and the deodorized product, and the analysis result by GC / MS.
[0020]
Example 2
475 parts by weight of polyglycerol (hydroxyl value 888 mgKOH / g, average polymerization degree 10) and 525 parts by weight of stearic acid were charged into a reactor equipped with a heating jacket and a stirrer. After adding 0.0062 parts by weight of 25% by weight aqueous sodium hydroxide solution, 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 decaglycerol tristearate, saponification value 110 mgKOH / g, acid value 0.30 mgKOH / g, ignition residue 0.01 weight) %) 966 parts by weight were obtained. 1000 parts by weight of water was mixed with 500 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 deodorized polyglycerol fatty acid ester (saponification value 110 mgKOH / g, acid value 0.35 mgKOH / g). . Table 1 shows the results of the sensory test of the non-deodorized product and the deodorized product, and the analysis result by GC / MS.
[0021]
Example 3
Example 1 The same treatment was performed to obtain a deodorized polyglycerin fatty acid ester (saponification value 70.6 mgKOH / g, acid value 1.25 mgKOH / g, ignition residue 0.20% by weight). Table 1 shows the results of the sensory test of the non-deodorized product and the deodorized product, and the analysis result by GC / MS.
[0022]
[Table 1]

Claims (5)

A reaction product obtained by reacting polyglycerin and a fatty acid in the presence of an alkali catalyst at a temperature of 200 ° C. or higher is mixed with 0.5 to 5 times by weight of water, and this mixture is formed into a thin film. Polyglycerin fatty acid ester obtained by evaporating and dehydrating under a reduced pressure of 10 to 150 Torr using an evaporator, and gas chromatograph / mass spectrometry (GC / MS), and phenyl acetate is 25.8 under the following conditions. All peaks detected in the range from the retention time at which 2,3-butanedione is detected to the retention time at which n-caproic acid is detected when measured to be detected at a retention time of min to 26.8 minutes Among them, the ratio (a / b) of the total area (a) of peaks other than the peak of phenyl acetate to the area (b) of the peak of phenyl acetate is 3.0 or less. Ester.
Analysis conditions;
Pretreatment conditions Headspace SPME
Container; Headspace vial, 10ml 22x45mm (Perkin Elmer compatible)
Sample: Phenyl acetate 2500 μg / ml in hexane solution
Polyglycerin fatty acid ester added to be pm Sample amount: 0.5 g
Adsorption phase; with liquid phase Fused silica fiber (Spelco) 50/30 μm DV
B / CAR / PDMS
Extraction conditions: 80 ° C. × 30 minutes, vapor phase desorption conditions: 5 minutes, 250 ° C. (gas chromatograph inlet)
GC / MS measurement conditions Column: HP-FFAP (50 m × 0.32 mm ID, Df = 0.52 μm) or the same
Separation column having a resolution such as: Column temperature: 40 to 240 ° C. (5 min hold → 5 ° C./min temperature rise)
Injection temperature: 250 ° C
Injection method: splitless, 6 minutes Ionization method: EI, 50-70 eV
Ion chamber temperature: 150 ° C
Measurement mode: Scan measurement, measurement mass range Mass number m / z = 35-300
GC / MS interface temperature; 240 ° C
Carrier gas; He A reaction product obtained by reacting polyglycerin and a fatty acid in the presence of an alkali catalyst at a temperature of 200 to 260 ° C. is mixed with 1 to 3 times the weight of water, and this mixture is evaporated into a thin film. A polyglycerin fatty acid ester obtained by evaporating and dehydrating under a reduced pressure of 20 to 100 Torr using a vacuum vessel and under a condition that the temperature of the polyglycerin fatty acid ester at the outlet of the thin film evaporator is 120 ° C. or lower. Retention of 2,3-butanedione detected by mass spectrometry (GC / MS) when phenyl acetate is detected at a retention time of 25.8 to 26.8 minutes under the following conditions: Of the total peaks detected within the retention time range in which n-caproic acid is detected from time, the total area (a) of peaks other than the phenyl acetate peak and the peak of phenyl acetate Polyglycerol fatty acid esters, wherein the ratio between the area (b) (a / b) is 3.0 or less.
Analysis conditions;
  Pretreatment conditions Headspace SPME
  Container; Headspace vial, 10ml 22x45mm (Perkin Elmer compatible)
  Sample: Phenyl acetate 2500 μg / ml in hexane solution
        Polyglycerin fatty acid ester added to become pm
  Sample amount; 0.5g
  Adsorption phase; with liquid phase Fused silica fiber (Spelco) 50/30 μm DV
          B / CAR / PDMS
  Extraction conditions: 80 ° C. × 30 minutes, gas phase
  Desorption conditions: 5 minutes, 250 ° C. (gas chromatograph inlet)
  GC / MS measurement conditions
  Column: HP-FFAP (50 m × 0.32 mm ID, Df = 0.52 μm) or the same
          Separation column with the same resolution
  Column temperature: 40-240 ° C. (5 min hold → 5 ° C./min temperature rise)
  Injection temperature: 250 ° C
  Injection method; splitless, 6 minutes
  Ionization method; EI, 50-70 eV
  Ion chamber temperature: 150 ° C
  Measurement mode: Scan measurement, measurement mass range Mass number m / z = 35-300
  GC / MS interface temperature; 240 ° C
  Carrier gas; He The polyglycerol fatty acid ester according to claim 1 or 2, wherein 50% (by weight) or more of the constituent fatty acid is an unsaturated fatty acid having 18 to 22 carbon atoms or a condensate thereof. The polyglycerin fatty acid ester according to any one of claims 1 to 3, wherein an ignition residue is 0.1 (wt)% or less. The polyglycerin fatty acid ester according to any one of claims 1 to 4 , wherein the polyglycerin has an average degree of polymerization of 4 to 12.