Method for catalytic synthesis of propyl gallate by immobilized enzyme method

Abstract

The invention discloses a method for catalytic synthesis of propyl gallate by an immobilized enzyme method. The method includes the following steps that (1) enzyme-producing bacteria are screened; (2)tannase is produced; (3) enzyme immobilization is carried out, specifically, graphene powder is taken, after modification treatment is carried out, modified graphene powder is obtained, the modifiedgraphene powder is added with distilled water and then subjected to ultrasonic dispersion to be even, graphene suspension is prepared, tannase is added to the graphene suspension, and the obtained mixture is stirred to obtain immobilized enzyme; (4) solvent treatment is carried out, specifically, the immobilized enzyme is added into organic solvent benzene, an activator is added, after stirring even is carried out, gallic acid and normal propyl alcohol are added immediately, heating and temperature keeping are carried out, after stirring is carried out for 8-10 hours, then ultrasonic treatingis carried out for 15-20min, stirring and reacting are continued for 7-8h, and filtering is carried out to obtain graphene filter residue and filtrate; and (5) post-reaction treatment is carried out.According to the method, the esterification reaction time is short, and the yield of propyl gallate is relatively high, so that the problems of long reaction time and low yield in the prior art are solved.

Description

technical field [0001] The invention belongs to the technical field of antioxidant preparation, and in particular relates to a method for catalytically synthesizing propyl gallate by an immobilized enzyme method. Background technique [0002] Propyl gallate (PG for short) is white to light brown crystalline powder or slightly milky white needle-like crystals. Its chemical name is 3,4,5-trihydroxybenzoic acid propyl ester. It has better performance than tert-butylhydroxyanisole (BHA) and 2,6-di-tert-butyl-p-cresol (BHT), and has good heat resistance. It is mainly used for anti-oxidation of fat or oil-based foods, and preservation of fruits and vegetables , can be used as anti-oxidation stabilizer or anti-aging agent for biodiesel and certain materials. Gallic acid ester compounds also have significant pharmacological and biological activities, can effectively eliminate free radicals, and are used for anti-oxidation and anti-microbial. Therefore, it is widely used in medicin...

AI Technical Summary

Problems solved by technology

The traditional method for preparing propyl gallate has the following disadvantages: (1) from preparing gallic acid to propyl gallate production process is loaded down with trivial details, and the cost is high, and the amount of waste water is big, is difficult to manage: (2) makes catalyst with traditional concentrated sulfuric acid, The yield is low, the reactant gallic acid is easily oxidized, there are many by-products, and the equipment is seriously corroded. If the waste liquid is directly discharged without treatment, it will cause great pollution to the environment.

(3) make catalyst with p-toluenesulfonic acid and add water-carrying agent, although yield improves, catalyst consumption is big, and is difficult for reclaiming, and environmental pollution

This technology is the activity of tannase improved by ink pad technology, and the production cost is high