3results about How to "Increased Resistant Starch Content" patented technology

The invention belongs to the field of molecular genetics, and provides a rice SS3a allele and application thereof in increasing the content of resistant starch in rice and reducing the glucose generation rate. The gene is deleted at the 2387th basic group G of the third exon of the rice SS3a gene and contains a gene sequence as shown in SEQ ID No. 1. The allele can significantly increase the amylose content in rice and change the amylopectin structure, so that the resistant starch content of rice is significantly increased, and the glucose generation rate of rice is reduced. Meanwhile, the allele can also significantly improve the gelatinization characteristic and the viscosity characteristic of the rice, and has small influence on the grain weight of the rice. The invention further relates to application of the new SS3a allele in rice breeding, the allele can be introduced through a cross breeding method, or the original SS3a gene is subjected to site-directed mutagenesis to form the allele, and the allele is used for cultivating a new high-resistance starch rice strain.

The application discloses a preparation method of a starch polypeptide compound capable of delaying digestibility, and improves the content of slow-digestible starch and resistant starch in the product; the method comprises the following steps: (1) in a weakly acidic aqueous phase reaction system, a sodium periodate is used as an oxidant to perform oxidation reaction on starch raw materials, and the hydroxyl groups at C2 and C3 positions of glucose units in the starch molecules are selectively oxidized and broken to generate corresponding dialdehyde structures; a food-grade reducing agent is added into the reaction system to terminate the oxidation reaction; (2) food-grade anhydrous ethanol is added into the reaction system of step (1) to precipitate the starch, and the solid precipitate is collected; the precipitate is washed by using an ethanol solution, and finally, the washed precipitate is dried, crushed and ground to obtain an oxidized modified starch raw material; (3) the oxidized modified starch raw material is uniformly mixed with polypeptides to obtain a mixture; then, the mixture is put into a double-screw extruder to perform extrusion compounding; the material extruded from the double-screw extruder is collected, dried and crushed to obtain the starch polypeptide compound.

This invention discloses a method for inhibiting the digestibility of rice starch gelatinized at high temperatures, comprising the following steps: subjecting soybean protein sequentially to ultrasonication, enzymatic hydrolysis, and acid-heat treatment to form heat-resistant and acid-resistant high aspect ratio rigid soybean protein fibers; mixing the obtained soybean protein fibers with a rice starch suspension, followed by gelatinization treatment to obtain a soybean protein fiber-rice starch complex. This invention, by constructing structurally stable soybean protein fibers, enables them to form a dense complex with rice starch during starch gelatinization and subsequent digestion, effectively inhibiting the digestibility of rice starch by α-amylase. The slow-digesting starch content reaches 20.48%~23.42%, and the resistant starch content reaches 30.11%~31.76%, approximately five times higher than that of natural rice starch. This invention requires no chemical cross-linking agents, and the process is green, safe, and controllable, suitable for the industrial production of low glycemic index foods.