Method for preparing diglyceride through continuous glycerolysis by enzyme method

Abstract

The invention relates to a method for preparing diglyceride through continuous enzymatic glycerolysis, which pertains to the technical field of gease modification. In the invention, glycerin, raw oil material and low-boiling single-phase organic solvent are fully mixed, and then continuous glycerolysis is carried out through a fixed bed reactor filled with immobilized lipase, and the products are distilled for removing the organic solvent to obtain the high-content diglyceride mixture. The invention greatly reduces the viscosity of the reaction system, improves the intersolubility of reaction materials, and protects the enzyme, thus improving the reaction efficiency and prolonging the service life of the enzyme.

Description

technical field [0001] The invention relates to a method for continuously preparing diglyceride by enzymatic method, which belongs to the technical field of oil modification. Background technique [0002] Diacylglycerol (DAG) is a natural component of oil and an intermediate product of oil metabolism. It is composed of one molecule of glycerol and two molecules of fatty acid, and has two isomers 1,3-DAG and 1,2-DAG, and the ratio of the two isomers in nature is 7:3. It is a food ingredient generally recognized as safe (GRAS) worldwide. Due to the different absorption and metabolism patterns of diacylglycerol and triacylglycerol, diacylglycerol has the functions of reducing visceral fat, inhibiting weight gain, and reducing blood lipids, so it has received extensive attention. Diacylglycerol has the flavor of ordinary oil and can replace edible oil in any proportion. Related products have been put on the market in Japan and the United States, and are deeply loved by consume...

AI Technical Summary

Problems solved by technology

[0005] However, the miscibility of glycerol and triglycerides is poor, and free glycerol can easily wrap enzymes and reduce enzyme activity

Therefore, under normal circumstances, it is difficult for lipase to catalyze the glycerolysis reaction

Many scholars have also improved this method, for example: ① U.S. Patent US6337414B1 provides a method for adding water to the reaction system to successfully realize the enzymatic glycerolysis reaction, because water is added in the method, so hydrolysis also occurs reaction, but a large amount of free fatty acids and monoglycerides are produced in the product, which increases the cost of separation of by-products

②Chinese patent CN200310112327.X provides a method of using oil and adsorbed glycerol as raw materials to prepare diglycerides through immobilized lipase catalyzed glycerol hydrolysis reaction. Adverse effects on enzymes, however, the adsorbent materials used are difficult to separate from enzymes and products, affecting the recycling of enzymes and the quality of products

③ Chinese patent CN200510002609.3 uses mixed oil as raw material, adds mixed solvent (n-hexane or n-heptane or cyclohexane mixed with tert-butanol), uses immobilized lipase to catalyze the glycerol hydrolysis reaction, and the reaction temperature is 38-42°C. The mutual solubility of the reaction substrate has been improved (also can not reach complete mixing), and the reaction efficiency has been improved. However, the raw material oil / mixed solvent ratio is 1: 1-5 (w / v), and the solvent usage is relatively large. The solvent has a high boiling point (n-heptane: 98.4°C, cyclohexane: 80.7°C, tert-butanol: 82.5°C), is not easy to volatilize, and is difficult to completely separate from the product

Among them, tert-butanol has a camphor smell and is moderately toxic. It is difficult to separate from other solvents and is generally not used in food production.

The proportion of recovered mixed solvents will also be out of balance during the recovery process, thus affecting the reuse of recovered solvents

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