15 results about "Starch Branching Enzyme" patented technology

To obtain buckwheat plants with modified starch properties. [Solution] According to the present invention, a buckwheat plant is provided in which the activity of starch branching enzyme 1 (SBE1) is reduced or deficient.

The invention relates to the field of plant molecular breeding, in particular to a rice SNP (Single Nucleotide Polymorphism) molecular marker and application thereof. The SNP site is located at the 19358817bp position of the second chromosome of the rice, and the polymorphism is T or A. The SNP site is a nucleotide sequence shown in the description. According to the invention, a corresponding KASP primer is designed aiming at the SNP site, and the primer is used for detecting the polymorphism of the SNP site to judge whether rice grains have high resistant starch content or not. The SNP molecular marker provided by the invention can effectively identify the genotype of the rice starch branching enzyme SBE3. The SNP molecular marker provided by the invention has the advantages of simplicity in operation, low cost, short period and the like, can accelerate the cultivation of the high-resistant starch rice variety when being applied to molecular marker-assisted selection, remarkably shortens the breeding period of the high-resistant starch rice variety, reduces the breeding cost, and has higher application value in the field of health food.

The invention relates to the technical field of deep processing of starch, in particular to a method for preparing dietary fiber, which comprises the following steps: (1) mixing starch with acid, and baking to obtain pyrodextrin; (2) performing enzymolysis modification on the pyrodextrin obtained in the step (1) in the presence of starch branching enzyme, and then performing saccharification treatment in the presence of glucamylase to obtain crude resistant dextrin liquid; and (3) mixing the resistant dextrin crude liquid obtained in the step (2) with inulin. According to the preparation method provided by the invention, the content of resistant components in the resistant dextrin crude liquid and the yield of the resistant dextrin can be improved, the preparation time of the resistant dextrin is greatly shortened, and the cost is saved. The prepared dietary fiber can be widely applied to food preparation, such as preparation of health-care products, special dietary foods, beverages, seasonings, candies or milk powder.

The present application relates to the field of plant molecular breeding, and particularly relates to a rice SNP molecular marker and application thereof. The SNP site is located at 19358817bp of the 2nd chromosome of rice, and the polymorphism is T or A. The present application designs corresponding KASP primers aiming at the SNP site, and detects the polymorphism of the SNP site by using the primers to determine whether the rice grains have high resistant starch content. The SNP molecular marker provided by the present application can effectively identify the genotype of rice starch branching enzyme SBE3 . The SNP molecular marker provided by the present application has the advantages of simple operation, low cost, short period, etc. When applied to molecular marker assisted selection, the breeding of high resistant starch rice varieties can be accelerated, the breeding period of high resistant starch rice varieties can be significantly shortened, the breeding cost can be reduced, and the application value in the field of health food is high.

The invention belongs to the field of food additives and specifically discloses a preparation process and application of lipophilic composite modified starch; the preparation process comprises the following steps: 1) using cassava starch as a raw material, and after mechanical activation, phosphorylating and cross-linking the cassava starch to obtain phosphate-modified starch; 2) pretreating the phosphate-modified starch to obtain a pretreatment liquid, and performing three-enzyme continuous modification and denaturation on the pretreatment liquid, wherein the three-enzyme continuous modification and denaturation comprises the following steps: 21) starch branching enzyme modification and denaturation, 22) beta-amylase modification and denaturation, and 23) pullulanase modification and denaturation; the starch of the invention is modified by sodium trimetaphosphate and subjected to three-enzyme continuous modification and denaturation at the same time, thereby compensating for the defects of single enzyme modification, and the obtained product has the dual properties of cross-linked starch and esterified starch, has the advantages of good hydrophilic and lipophilic properties, high viscosity, freeze-thaw resistance, dehydration (aging) resistance, and the like, thereby making the product have better practicality.

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.

The invention discloses canna edulis ker starch resistant dextrin as well as a preparation method and application thereof. The method comprises the following specific steps: crushing canna edulis ker starch, and mixing the crushed canna edulis ker starch with water to form homogeneous slurry; pyrodextrin is generated through acid catalysis coking pyrolysis; carrying out enzymolysis purification by using alpha-amylase, carrying out branched chain re-synthesis by using starch branching enzyme, and removing residual reducing sugar by combining with saccharomyces cerevisiae fermentation; and carrying out graded purification by adopting an ultrafiltration membrane, and finally drying to obtain a resistant dextrin finished product. The embodiment verifies that the obtained resistant dextrin has excellent freeze-thaw stability (the transmittance is greater than or equal to 80% after freeze-thaw for five times) and digestion resistance (the proportion of anti-digestion components reaches 92.4%), and the product is light in color and excellent in sensory quality. The method disclosed by the invention is simple and convenient in process operation and high in efficiency, solves the problems of high energy consumption and low yield of a traditional method, provides technical support for developing functional foods and auxiliary therapeutic preparations for metabolic syndromes, and promotes high-valued utilization of canna edulis ker resources at the same time.

The invention discloses a starch branching enzyme IIb mutant protein for reducing rice amylose, a mutant gene and application thereof. According to the mutant gene, the 43rd basic group T of the 9th exon of the SBEIIb gene of a wild rice variety Zhonghua 11 is replaced by C, so that the 312th serine S of the protein is replaced by proline P. According to the rice SBEIIb mutant protein, the amylose content of rice can be remarkably reduced to 12.0% from 13.7% of a wild type, the starch gelatinization initial temperature is remarkably increased to 72.0 DEG C from 61.9 DEG C of the wild type, the starch gelatinization peak temperature is remarkably increased to 79.4 DEG C from 69.7 DEG C of the wild type, meanwhile, the appearance of the rice is kept transparent, and the rice amylose content is remarkably reduced to 12.0% from 13.7% of the wild type. The method has strong application in rice quality improvement breeding and starch food industry.

The invention discloses a high-activity and high-stability starch branching enzyme as well as preparation and application thereof, and belongs to the technical field of biology. A wild type starch branching enzyme truncated body PtGBE is expressed in E.coli BL21 (DE3), the amino acid sequence of the wild type starch branching enzyme truncated body PtGBE is shown in SEQ ID NO.1, gene site-directed modification is carried out on the PtGBE, the mutant type PtGBE with high activity and high stability is obtained, and the amino acid sequence of the mutant type PtGBE is shown in SEQ ID NO.3. The specific enzyme activity of the mutant type PtGBE is 7119.35 U / mg and is improved by 119% compared with that of PtGBE, and the thermal stability and the pH stability are improved. After in-vitro digestion experiment analysis, the content of resistant starch is increased, the content of cassava starch RS is increased to 73.81%, and the content of pyrodextrin RS is increased by 5.83%.

The invention discloses a preparation method of rice noodles with strong satiety. The preparation method comprises the following steps: (1) treating natural waxy corn starch by using plant-derived starch branching enzyme explored by an applicant; (2) modifying cassava starch: dissolving cassava starch in water to prepare starch milk, and performing ultraviolet radiation and magnetic field treatment to obtain modified cassava starch; (3) selecting high-quality protein: selecting soybean protein isolate and whey protein as the high-quality protein; and (4) preparing the rice noodles, and performing vacuum packaging. Slow digestible starch is prepared through an SBEIIb enzyme method, cassava starch is modified, high-quality protein (soybean protein isolate and whey protein) is compounded, and process optimization is combined, so that the palatability of the rice noodles is maintained, and meanwhile, the satiety effect is precisely regulated and controlled, and the long-acting energy supply requirement in a complex military environment is met.

Materials and methods are provided for making plants (e.g., Triticum varieties) with increased levels of dietary fiber, such as by making TALE nuclease-induced mutations in alleles encoding starch branching enzyme IIa (SBEIIa) and starch branching enzyme IIb (SBEIIb).

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.

The invention relates to a method for preparing high-resistance starch through synergy of double enzymes, and belongs to the technical field of enzyme engineering and food processing engineering. The method comprises the following steps: preparing starch emulsion from starch and water, heating and gelatinizing the starch emulsion, and performing constant-temperature water bath; adding starch branching enzyme for water bath enzymolysis, performing boiling water bath enzyme deactivation and cooling; adding cane sugar, stirring and dissolving, adding amylosucrase for water bath enzymolysis, and adding absolute ethyl alcohol to terminate the reaction; and separating out solids, washing and freeze-drying to obtain the high-resistance starch. Through the synergistic effect of the starch branching enzyme and the amylosucrase, the production efficiency of the resistant starch is remarkably improved, the structural characteristics of the product are optimized, B-type crystals with high-stability double-helix conformation are formed, the digestion resistance characteristic is remarkably enhanced, various cereal raw materials with low amylose content can be effectively treated, and the raw material adaptability is high.