Method for preparing peptide with high antioxidant activity by utilizing rice residue protein treated by superhigh pressure

Abstract

The invention relates to a method for preparing peptide with high antioxidant activity by utilizing rice residue protein treated by superhigh pressure. The method comprises the following steps: (1) pretreating rice residues so as to obtain rice residue powder; (2) extracting the rice residue protein: mixing the rice residue powder and water so as to obtain a mixture, regulating the pH value of the mixture to be 11-13, stirring the mixture for a reaction, performing centrifugation so as to collect supernatant, regulating the pH value of the supernatant to 5.0-5.8, precipitating the supernatant of which the pH value is regulated, centrifuging the precipitated supernatant and washing the centrifuged supernatant so as to obtain the rice residue protein; (3) treating the rice residue protein through superhigh pressure: treating the rice residue protein under the superhigh pressure, and freeze drying the treated rice residue protein so as to obtain superhigh-pressure rice residue protein powder; (4) performing enzymolysis: compounding the superhigh-pressure rice residue protein powder into an aqueous solution, performing enzymolysis on the aqueous solution, performing enzyme deactivation on the queous solution after enzymolysis, centrifuging the queous solution on which the enzyme deactivation is performed, and collecting supernatant; (5) performing vacuum concentration on the supernatant so as to obtain a concentrated solution; and (6) freeze drying the concentrated solution so as to obtain the peptide with high antioxidant activity. Products obtained by the method disclosed by the invention have higher antioxidant activity; compared with products which are not treated through the superhigh pressure, the clearance rate for DPPH free radicals, the clearance rate for ABTS free radicals and the clearance rate for hydroxyl free radicals in the products obtained by the method disclosed by the invention are greatly increased respectively.

Description

technical field [0001] The invention relates to a method for preparing antioxidant peptides, in particular to a method for preparing peptides with high antioxidant activity by using ultra-high pressure to treat rice dregs protein. Background technique [0002] Rice is one of the most important grains in the world. China is a well-known large grain-producing country. More than 85% of grain production is rice. The commercial grain inventory in Hunan Province alone is between 4.3 million and 6.6 million tons per year. Part of the grain needs to be used in the industrial production of starch sugar, but a large amount of by-product rice dregs will be produced, and the protein content in rice dregs is as high as 40-70%. The quality of rice protein is recognized as the best among cereal proteins. The nutritional value of rice protein is higher than that of wheat protein. Reasonable, higher biological value and protein utility ratio compared to other cereal proteins. In addition, ...

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Problems solved by technology

[0003] CN101748182B discloses a method for preparing rice protein antioxidant peptides. The technical solution is to sieve rice dregs and soak them in water, then use a colloid mill to grind them and then perform enzymatic hydrolysis to finally prepare rice protein antioxidant active peptides, but , the use of colloid mill will produce a lot of foam, which will affect the accuracy of the experiment, and the degree of hydrolysis by alkaline protease is not effective

CN103540637A discloses a method for preparing high-purity rice protein peptides by high-pressure treatment and enzymatic hydrolysis. The technical scheme is rice dregs pretreatment, high-pressure homogenization, ultrasonication, enzymatic hydrolysis, decolorization, separation, and drying. However, the highest pressure used It is 80MPa. Studies have shown that such pressure cannot completely destroy the basic structure of the protein, and cannot allow the protein to be better enzymatically hydrolyzed

CN103283934A discloses a method for preparing high-purity rice protein. The rice dregs protein extraction scheme is enzymatic extraction followed by high-pressure treatment. However, enzymatic extraction will produce more impurities. higher

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