JPH06157576A - Purification of sucrose fatty acid monoester - Google Patents

Abstract

PURPOSE:To obtain a highly pure sucrose monoester of a fatty acid from a mixture of sucrose esters of the fatty acid containing the sucrose monoester and polyesters of the fatty acid. CONSTITUTION:A mixture of sucrose esters of a fatty acid is dissolved in water and extracted with ethyl acetate by liquid-liquid extraction. As a monoester is much more distributed in water phase than the other esters, the water phase is concentrated to collect the sucrose esters enriched in the monoester.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for obtaining a monoester-enriched sucrose fatty acid ester from a sucrose fatty acid ester mixture.

[0002]

BACKGROUND OF THE INVENTION Sucrose fatty acid esters are those in which sucrose and fatty acids are ester-bonded to each other. Depending on the degree of substitution of hydroxyl groups in sucrose molecules (hereinafter referred to simply as the degree of substitution), various esters from monoesters to octaesters Esters are present. The sucrose fatty acid ester has different HLB value, emulsifying power, and other characteristics depending on the degree of substitution and the number of carbon atoms in the fatty acid.

One of the representative industrial processes for producing sucrose fatty acid ester is a method by transesterification reaction between sucrose and a lower alkyl ester of fatty acid, especially methyl or ethyl ester, which is obtained by this method. Sugar fatty acid esters are generally mixtures of various esters with different degrees of substitution. The sucrose fatty acid ester is usually used as it is as a mixture of various esters having different substitution degrees, but it may be desirable to use the ester having a specific substitution degree depending on the application. For example, the ratio of monoester is 9
Those having a content of 0% or more are known to be used as pharmaceutical auxiliaries, absorption enhancers, solubilizers, etc. (JP-A-61-1916).
10, refer to JP-A-2-149597). Further, those having a monoester ratio of 99% or more are used as biochemical reagents and protein (membrane proteins, enzymes, etc.) solubilizers.

[0004]

As a method for obtaining such a sucrose fatty acid ester having a high monoester ratio,
For example, a method by column chromatography using a synthetic adsorbent as a filler is known (Japanese Patent Laid-Open No. 61-1481).
90). However, this method is not always advantageous as an industrial refining method, and an alternative method is required.

[0005]

Means for Solving the Problems The present inventors have focused on the fact that the distribution ratio of sucrose fatty acid ester to water and an organic solvent varies depending on the degree of substitution. As a result of studies to obtain enriched sucrose fatty acid ester, it was found that acetic acid ester is suitable as the organic solvent. That is, when a sucrose fatty acid ester mixture is subjected to liquid-liquid extraction using water and a lower alkyl ester of acetic acid, the monoester is concentrated in the aqueous phase and the polyester is concentrated in the acetic acid ester phase.
After separating both phases, the monoester-enriched sucrose fatty acid ester can be obtained from the aqueous phase.

The present invention will be described in more detail. The sucrose fatty acid ester mixture used in the liquid-liquid extraction in the present invention may have any composition as long as it contains a monoester, but the average degree of substitution is low. Those having a monoester ratio of 50 to 90 (weight)% are preferable. Also,
The constituent fatty acids may be arbitrary, but usually have 6 to 6 carbon atoms.
24, preferably 8 to 22 saturated and / or unsaturated fatty acids. Representative fatty acids are caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, oleic acid, myristic acid, erucic acid and the like. These may be a mixture derived from a natural product, or may be purified to various purities.

As a suitable sucrose fatty acid ester mixture that can be obtained on the market, Ryoto (registered trademark) sugar ester CE-169 manufactured by Mitsubishi Kasei Foods Co., Ltd. is used.
5 (95% by weight or more caprylic acid as a constituent fatty acid and an average degree of substitution of 1.3), CT-1695 (95% or more caprylic acid as a constituent fatty acid or more, an average degree of substitution of 1.3), L
-1695 (95% (by weight) of lauric acid is a constituent fatty acid)
As described above, the average degree of substitution is 1.3), O-1570 (70% by weight of oleic acid as a constituent fatty acid, and the average degree of substitution is 1.3).

In the present invention, these sucrose fatty acid ester mixtures are subjected to liquid-liquid extraction using water and a lower alkyl ester of acetic acid. Methyl acetate or ethyl acetate is usually used as the acetic acid ester. The liquid-liquid extraction is usually carried out by dissolving the sucrose fatty acid ester mixture in water so as to be 1 to 90 (wt)% and extracting the mixture with acetate at 10 to 80 ° C. It is preferably dissolved in water so as to be 1 to 40 (wt)% and extracted at 20 to 60 ° C. Generally, the higher the extraction temperature is, the larger the distribution ratio of the monoester to the aqueous phase is, but if the temperature is too high, there is a risk that the sucrose fatty acid ester will be hydrolyzed. In order to avoid hydrolysis, the pH of the aqueous phase is preferably 3 to 11, particularly preferably neutral. The ratio of the aqueous phase to the acetate phase is arbitrary, but is usually 1: 4 to 4: 1 by volume.

The extraction can be carried out by using any known device such as a mixer settler or a rotary disc extraction tower. Further, the extraction operation may be either continuous or batch. In the case of multistage extraction, either countercurrent multistage extraction or parallel flow multistage extraction can be performed. In the extraction, the aqueous phase and the acetic acid ester phase may be in an emulsified state and may not be easily separated, but in such a case, they can be easily separated by using a centrifuge.

[0010]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Example 1 Ryoto (registered trademark) was added to a stirring tank having an internal volume of 500 ml.
100 g of a 10 (wt)% aqueous solution of sugar ester L-1695 (weight composition: monoester 80.9%, diester 16.7%, triester 2.4%) was added.
Next, 100 g of methyl acetate was added thereto, and the mixture was stirred at room temperature for 5 minutes and then allowed to stand for 10 minutes to separate layers. The aqueous phase was concentrated to dryness to obtain a monoester-enriched white sucrose fatty acid ester. The yield was 27.8%. The composition of this product was analyzed by gel permeation chromatography to find the composition (area%) of the monoester, which was 92.3%.

Example 2 The procedure of Example 1 was repeated except that ethyl acetate was used instead of methyl acetate.
Yield 87.3% and its monoester composition is 86.7%.
Met.

Example 3 100 g of a 10% (by weight) aqueous solution of the same sucrose fatty acid ester as used in Example 1 was placed in a stirring tank having an internal volume of 500 ml, 50 g of ethyl acetate was added thereto, and the mixture was stirred at 30 ° C. for 5 minutes. did. The solution was allowed to stand and separated into an aqueous phase and an ethyl acetate phase (first extraction). The aqueous phase was returned to the stirring tank, 50 g of ethyl acetate was added thereto, and the mixture was stirred at 30 ° C. for 5 minutes and then allowed to stand to perform stratification (second extraction). In this way, the extraction operation was repeated 10 times. The results are shown in Table 1.

Examples 4 to 7 The procedure of Example 3 was repeated, except that the concentration of the aqueous sucrose fatty acid ester solution, the amount of ethyl acetate used and the extraction temperature were changed as shown in Table 1. . The results are shown in Table 1.

[0014]

[Table 1]

Examples 8 to 10 A rotary disk extraction column (height: about 160 cm, number of stages: 60, rotation number: 170-200 rpm) was added from the top to Ryoto (registered trademark) sugar ester CT-1695 (weight composition:
An aqueous solution of monoester 84.7%, diester 14.3%, triester 1.0%) was supplied at 3.0 kg / hour, and ethyl acetate was supplied at 6.0 kg / hour from the lower part to perform continuous multistage countercurrent extraction. It was The results are shown in Table 2.

[0016]

[Table 2]

Example 11 Ryoto (registered trademark) was placed in a stirring tank having an internal volume of 500 ml.
100 g of a 10 (weight)% aqueous solution of sugar ester O-1570 was added, 150 g of ethyl acetate was added thereto, and the mixture was stirred at 30 ° C. for 5 minutes. The solution was allowed to stand and separated into an aqueous phase and an ethyl acetate phase (first extraction). The aqueous phase was returned to the stirring tank, 150 g of ethyl acetate was added thereto, and the mixture was stirred at 30 ° C. for 5 minutes and then allowed to stand to perform stratified separation (second extraction). In this way, the extraction operation was repeated 6 times. Yield 15.3
%, The monoester composition was improved from 70.6% to 99.6%. At the end of the sixth stirring, the liquid separation did not work well on standing, so liquid separation was performed using a centrifugal separator at a centrifugal acceleration of 2000 G for 10 minutes.

[0018]

According to the present invention, a monoester-enriched sucrose fatty acid ester can be easily obtained by a simple means of liquid-liquid extraction.

Claims (4)

[Claims] 1. A sucrose fatty acid ester mixture containing a monoester of sucrose fatty acid and a polyester is subjected to liquid-liquid extraction using water and acetic acid ester, and sucrose enriched in a monoester ratio from an aqueous phase. A method for purifying sucrose fatty acid monoester, which comprises obtaining a fatty acid ester. 2. The purification method according to claim 1, wherein the acetic acid ester is methyl acetate or ethyl acetate. 3. The purification method according to claim 1, wherein the sucrose fatty acid ester mixture contains 50 to 90 (weight)% of sucrose fatty acid monoester. 4. The purification method according to claim 1, wherein the liquid-liquid extraction is performed at a temperature of 10 to 80 ° C.