Method for preparing isomaltulose by immobilizing sucrose isomerase-producing cells of polyvinyl alcohol

Abstract

The invention discloses a method for preparing isomaltulose by polyvinyl alcohol immobilized sucrose isomerase producing bacteria. The polyvinyl alcohol immobilized sucrose isomerase producing bacteria are obtained by adding 5 to 30 weight percent of sucrose isomerase producing wet bacteria into 4 to 50 percent of water solution pulp of an enzyme carrier which is polyvinyl alcohol or / and kieselguhr at 25 to 30 DEG C and uniformly stirring and hardening at -20 DEG C for later use, wherein the ratio of polyvinyl alcohol to kieselguhr is 2:(0.8-1.21). When used, the immobilized enzyme producing bacteria are taken out, naturally unfrozen at room temperature, cut into grains and added into sucrose solution to perform isomerization conversion; then produced sucrose isomerase is used to decompose sucrose remaining in conversion solution; the conversion solution is purified by decolorizing and ion exchange; and an isomaltulose product is obtained by concentration crystallization and centrifugal separation. The method has the advantages that: the operation is simple and efficiency; the material is cheap and readily available; the grains of immobilized bacteria have high strength and are insusceptible to breakage; the activity of sucrose isomerase is high; the service life of the sucrose isomerase is long; and the like. The isomaltulose has high quality, the purity of the isomaltulose is over 98 percent, the sucrose residue content is less than 0.1, and the isomaltulose is more suitable for preparing high-quality isomalt by hydrogenation.

Description

technical field [0001] The invention belongs to the field of functional sugar production and relates to a method for preparing isomaltulose by immobilizing sucrose isomerase-producing bacteria with polyvinyl alcohol. Background technique [0002] Isomaltulose, also known as Palatinose, is a reducing disaccharide, which was first discovered by Weidenhagen et al. in sugar beet production in 1957. The industrialized production of isomaltulose is based on sucrose as raw material, isomerized by sucrose isomerase (also known as α-glucosyltransferase) to form isomaltulose syrup, then decolorized and purified, concentrated and crystallized, centrifuged and dried. get. Isomaltulose has similar sweetness properties to sucrose, its sweetness is about half that of sucrose, without any off-flavor. Compared with sucrose, the outstanding advantages of isomaltulose are: (1) low cariogenic properties; (2) suitable for diabetics. As a promising functional sweetener, isomaltulose has been w...

AI Technical Summary

Problems solved by technology

[0015] The purpose of the present invention is to: aim at the shortcomings of the current sodium alginate immobilization method, to provide a simple and fast operation, high strength of immobilized bacteria, easy preservation of immobilized bacteria, less loss of enzyme activity and no pollution and waste. The enzyme carrier polyvinyl alcohol immobilizes the bacteria, and provides a method to decompose the residual sucrose in the conversion solution by producing sucrose isomerase, effectively reducing the sucrose content in the isomaltulose obtained after crystallization to prepare high-quality isomaltulose method