JPH0439320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention It is known that higher fatty acid esters of sugars and sugar alcohols can be chemically synthesized by transesterification of fatty acid esters with sugars or sugar alcohols. Sugar fatty acid esters are produced in large quantities by this method. Since all of these chemical synthesis methods involve a heating step, they have drawbacks such as coloring of the product due to heating and the formation of complex mixtures.

In order to avoid these drawbacks, a biochemical synthesis method for fatty acid esters using free fatty acids and sugars or sugar alcohols as substrates and incubation in the presence of lipase has recently been proposed, and a patent application is currently being filed by the present applicants. . Since the incubation is carried out in an aqueous medium such as water or a buffer and under stirring, the substrate concentration cannot be too high. For this reason, energy costs are required to recover the product after the reaction is completed, and as is well known, the esterification reaction between acid and alcohol is a reversible reaction, so a low substrate concentration is disadvantageous for the esterification rate. It is.

In order to improve this point, the present inventors have proposed a method for synthesizing fatty acid esters by incubating sugar or sugar alcohol as a substrate in the presence of lipase. It is characterized by incubating in an aqueous medium in an amount that can completely dissolve the above, while gradually removing moisture under reduced pressure, and after the final moisture content becomes 5% or less, incubation is continued by leaving it at normal pressure. We have proposed a method for producing fatty acid esters, and are currently applying for a patent.

By the way, in this enzymatic reaction, until now it has been said that water is necessary for the substrate to dissolve, or that enzymes are proteins and require water to perform their actions. In addition, it was said that the concentration of fatty acids could not be increased very much due to inhibition of enzymes by fatty acids. Therefore, it was inconceivable to mix enzymes directly with substrates, especially fatty acids, without water.

DISCLOSURE OF THE INVENTION The present invention uses sugar or alcohol as one substrate and fatty acid as the other substrate, and incubates in the presence of lipase.
This is a method for synthesizing fatty acid ester, which is characterized by continuing incubation in a state where the water content of the reaction system is lower than 5% without reducing the pressure and leaving the reaction system stationary.

The present invention uses sugar or alcohol as one substrate and fatty acid as the other substrate, and by incubating in the presence of lipase,
A method for synthesizing a fatty acid ester, characterized in that incubation is continued by thoroughly mixing the substrate and lipase and providing water by addition or humidification if water necessary for the reaction is required. Concerning the manufacturing method.

Contrary to conventional wisdom, the present inventor directly mixed enzymes with sugars or sugar alcohols and fatty acids, stirred them in a dispersed state, and added water little by little if necessary in a constant temperature bath, or humidified the enzymes under high humidity. When a fatty acid ester was synthesized by adding moisture to the ester, it was surprisingly confirmed that the ester synthesis proceeded in a high yield, and the present invention was completed. In this case, the moisture content of the reaction system is lower than 5%, preferably 4% or less.

This reaction is characterized by the fact that the reaction proceeds with minimal water content, so the esterification yield is high and there is no need for dehydration after the reaction.

Moisture in the reaction system refers to the water in the entire reaction system, such as substrates and enzymes, and includes water added as necessary.
In some cases, it also includes moisture absorbed from the atmosphere, and in some cases, moisture generated by reactions. Examples of sugars that can be used in the present invention include monosaccharides such as glucose, fructose, ribose, arabinose, mannose, galactose, and xylol, disaccharides such as sucrose, maltose, lactose, cellobiose, trehalose, and palatinose, maltotriose, and raffinose. , trisaccharides such as cellotriose and mannotriose, tetrasaccharides such as cellotetrose and stachyose, dextrin, cyclodextrin, mannan, fructan, galactan, xylan, alaban, cellulose, cellulose derivatives (CMC, hydroxypropylcellulose, methylcellulose), etc. .

Examples of sugar alcohols include sorbitol, sorbitan, arabitol, xylitol, mannitol, dulcitol, maltitol, lactitol, and parathitol.

The fatty acid is preferably a saturated or unsaturated fatty acid having 8 to 22 carbon atoms. For example,
Saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, bevenic acid, caproleic acid, Linderic acid, myristoleic acid, palmitoleic acid, oleic acid, cadreic acid, erucic acid,
Unsaturated fatty acids such as decadienoic acid, linoleic acid, hyalic acid, linolenic acid, eicosatrienoic acid, docosatrienoic acid, hexadecatetraenoic acid, stearidonic acid, arachidonic acid, docosatetraenoic acid, eicosapentaenoic acid, sardine acid, Hydroxy fatty acids include sabinic acid, iprolic acid, yarapinoleic acid, ricinoleic acid, and feronic acid.

As is well known, there are lipases derived from microorganisms and those derived from animals, and both can be used.

As for those derived from microorganisms, Aspergillus
niger (manufactured by Amano Pharmaceutical, lipase AP-6), Mucor (manufactured by Amano Pharmaceutical, lipase MAP-10), Mucor
miehei (manufactured by Novo Industries, Lipase SP-
225), Pseudomonas (Amano Pharmaceutical, Lipase P),
Phizopus japonicus (manufactured by Osaka Seiken Co., Ltd., Lipase Cyken "100"), Phizopus delemor (manufactured by Tanabe Seiyaku Co., Ltd.,
Talypase), Candida cylindracea (Meito Sangyo Co., Ltd., Lipase MY), etc. Examples of animal sources include pancreatin derived from pig pancreas.

The molar ratio of sugar or sugar alcohol to fatty acid in the starting reaction mixture is preferably in the range of 1:3 to 3:1. The amount of enzyme added depends on the potency, but in the case of the commercial products exemplified, it is generally 0.1-10% of the total weight of the substrate.

The incubation temperature depends on the heat resistance of the enzyme, but is generally in the range of 30°C to 50°C, with the optimum temperature being around 37°C. However, in the case of thermostable enzymes, the temperature may exceed 40°C.

Mix the substrate and enzyme and incubate with thorough stirring. If necessary, add water or buffer so that the moisture content is lower than 5%, preferably 1% or less, or keep the constant temperature room at a humidity of 80 to 100%. Moisture is added through humidification. The reaction is completed in about 2 to 4 days, depending on the amount of enzyme added.

After the reaction is complete, for example, remove oil-soluble components (fatty acids, fatty acid esters) from the reaction mixture using chloroform,
The target fatty acid ester can be isolated by a conventional method by extraction with a solvent such as tetrahydrofuran.

Examples of the present invention are shown below.

Example 1 9.1g of sorbitol and oleic acid in a 100 beaker
Add 14.1 g, and add 0.5 g of lipase derived from Candida cylindracea (Lipase MY, manufactured by Meito Sangyo) and disperse. After stirring with a magnetic stirrer and incubating at 37° C. in a humidity of 90%, the esterification rate was 86% based on fatty acids after 72 hours. The average moisture content of the reaction system was 3.5%.

Example 2 Add 19 g of sucrose and 8 g of caprylic acid to a 100 beaker, and add lipase derived from Phizopus japonicus (Lipase Saiken "100" manufactured by Osaka Saiken Co., Ltd.)
Add 1.0g and disperse.

Stir with a magnetic stirrer and add pure water.
Add 0.08g and incubate at 40℃.
After 72 hours, the esterification rate was 87% based on fatty acids. The average moisture content of the reaction system was 0.5%.

Claims (1)

[Claims] 1 sugar or sugar alcohol as one substrate,
In the method of synthesizing fatty acid esters by incubating in the presence of lipase using a fatty acid as the other substrate, the reaction system is incubated without reducing pressure and left standing, with the moisture content of the reaction system being lower than 5%. A method for producing fatty acid ester, which is characterized by being continuous.