4 results about "Starch Branching Enzyme" patented technology

The application discloses a kind of double-enzyme modified starch with high freeze-thaw stability and its preparation method and application, for the serious problem of gel structure deterioration and water separation of starch-based frozen food caused by ice crystal damage in repeated freeze-thaw process, the method utilizes malt alpha-amylase and starch branching enzyme to catalyze different crystal form starch particles in sequence, and realizes the directional regulation of starch branching topological structure by the synergistic mediation of glycosidic bond reconstruction. First, the malt alpha-amylase hydrolyzes the starch particles moderately, and the long internal chain connected to the molecular cluster is cracked; then the starch branching enzyme cuts off the alpha-1,4 glycosidic bond, and connects the free malt oligosaccharide to the cluster-shaped molecular residue with alpha-1,6 glycosidic bond, thereby significantly increasing the branching degree of starch. The method disclosed in the application belongs to enzyme modification, and has the characteristics of green safety and simple operation, and has wide application prospect in frozen food, such as instant noodles and instant rice products.

This invention discloses a method for producing resistant dextrin using starch branching enzyme and α-amylase. The specific steps include: preparing pyrodextrin from corn starch via acid-thermal catalysis; then, purifying and resynthesizing the branched chains using starch branching enzyme and α-amylase; further purifying by fermentation with Saccharomyces cerevisiae; and finally, drying to obtain the resistant dextrin product. Through examples, this invention demonstrates that the obtained resistant dextrin possesses excellent glucose binding and retention capabilities, as well as resistance to digestion (resistance component ratio reaches 86.97%), good solubility, and freeze-thaw stability, making it well-suited for applications in the beverage and other industries. This provides a new, efficient, and environmentally friendly approach for the preparation and application of resistant dextrin.

The invention discloses a bacillus subtilis genetic engineering strain for high yield of starch branching enzyme (1, 4-alpha-glycan branching enzyme (GBE)), and a construction method and application of the bacillus subtilis genetic engineering strain. According to the bacterial strain, bacillus subtilis DB403 (B.subtilis DB403) is used as an original host, and an optimized host bacterial strain is obtained by knocking out an upp gene, an alpha-amylase gene amyA, an autolysis key gene sigD and the like; the method comprises the following steps: screening a combination of a bacillus subtilis high-copy vector and a strong promoter through a system to obtain an optimized recombinant expression plasmid; and introducing the expression plasmid into the host strain to construct the engineering strain. The GBE intracellular enzyme activity of the strain reaches 18104.32 U / mL and is improved by 64.58% compared with that of an original system, and the strain has wide application prospects in the fields of starch modification and functional food development.

The present invention belongs to the field of starch biotechnology, and relates to a method for preparing low-GI maltodextrin by means of the synergy of double enzymes. The method of the present invention comprises: dispersing starch particles in water to obtain starch milk; adding a starch branching enzyme Ro-GBE to the starch milk, heating same for gelatinization, cooling same and then performing a constant-temperature reaction to obtain a reaction liquid 1; cooling the reaction liquid 1, adding β-amylase, and reacting same with yeast to obtain a reaction liquid 2; and drying the reaction liquid 2 to obtain low-GI maltodextrin. In the present invention, the branching degree of the product modified by means of an enzymic method is increased, the relative molecular mass is reduced, and a highly-branched small molecular structure is formed, thereby delaying the digestibility of the product and enhancing the solubility and the solution stability of the product. In the present invention, by using the starch branching enzyme and the β-amylase to perform synergistic secondary enzymolysis modification on the starch, fast digestion components in the product can be reduced by 42.71%, the product is soluble in cold water, and the transparency of the solution can still reach 90.00% or higher after storage at 4°C for 30 d.