The Research Of UHP Treatment On Rice Residue Protein Hydrolyzate Antioxidant Activity

Rice residue protein is a major by-product of deep processing of rice, which is the quality of the natural peptide hydrolysis antioxidants, easy sources of raw materials, low cost, no allergic reactions, consumers readily accept. Rice residue protein and abroad now mainly used as animal feed after drying, or only a portion of undetermined enzymatic modification, industrial added value is very low. This project uses rice residue protein production rice residue protein antioxidant peptides, make up the domestic rice functional peptide product blank, as a base to develop infant formula products, health or functional food ingredients, ordinary food ingredients and cosmetics, to improve rice utilization level, to achieve multiple conversions added significance.In this paper, alkali-soluble acid formulation rice residue protein extract to extraction rate indicators rice residue protein of rice residue protein alkali extraction conditions were optimized:The ingredients rice residue and rice residue protein analysis, meters residue extracted protein content of about 83.67%,52.56% relative raw rice residue, the protein content increased a lot; experimentally determined rice residue protein isoelectric point of 5.4; using single factor experiment and response surface combination the way to determine the rice protein alkali extraction optimum conditions:rice residue crush size of 80 mesh, solid-liquid ratio 1:10, extraction temperature 44.5 ℃, extraction time 3h, pH 12.35, verification results show that in this condition under rice protein extraction rate of about 69.68%.Using a variety of rice residue protein protease enzyme to a degree of hydrolysis index, the final choice was neutral protease digestion experiments as an enzyme source, the use of single-factor experiment and response surface test combination, with ABTS radical scavenging rate index for rice residue proteolytic processing conditions were optimized to determine the optimum conditions for the rice residue proteolysis:[E]/[S] of 1.88%, hydrolysis time 3.9h, hydrolysis temperature to 40.16 ℃, [S] 2%, to verify in this condition, rice residue protein hydrolysates ABTS radical scavenging rate of about 72.68%.Design experiments for rice residue protein UHP handle different pressure and time, the hydrolyzate measured antioxidant activity, radical scavenging three indicators show 400MPa under treatment after 10min, the antioxidant activity of enzyme solution the best performance, while measuring the change in the degree of hydrolysis of EHV around hydrolysis process, the results show the strength of ultra-high pressure can enhance digestion, speed up digestion process so that rice residue proteolysis more thoroughly.To explore the UHP on rice residue protein hydrolyzate antioxidant activity enhancement mechanism, this experiment further distribution analysis experiments by SDS-PAGE gel electrophoresis, laser particle size, Fourier transform near infrared spectroscopy experiment, scanning electron microscopy experiments, amino acid type and content analysis of experiments, hydrolyzate peptide molecular weight distribution analysis experiments to explore the initial mechanism; electrophoresis experiments show that EHV make rice residue protein subunit dissociation phenomenon occurred in part, but did not change the primary structure of rice residue protein; laser particle size distribution analysis showed that EHV will greatly reduce the average particle size of rice residue protein solution so that the process of digestion enzyme and substrate binding reaction more thoroughly; and Fourier near infrared scanning results, after the high pressure treatment of protein degradation intensifies, the whole extent of protein molecules in solution ionization strengthened to increase the charge distribution on the molecule, protein exposed more hydrophilic groups, promote enzymatic reaction is carried out; EHV samples before and after the type and content of amino acids were analyzed and found EHV and did not change the structure of the amino acid species, but there is a certain degree of influence on the content, there are some major improvements in terms of some of the content of amino acid has antioxidant activity, which also lead to changes in rice residue protein hydrolyzate antioxidant activity; against hydrolysis After a relative molecular weight distribution was found, UHP will be some of the macromolecular peptide hydrolysis into more small peptides, and a large number of studies have shown that small molecule peptide is the main antioxidant substances.Based on the above experiment, high pressure treatment rice residue protein hydrolyzate and improve its antioxidant activity of the preliminary inquiry, reveals the EHV rice residue protein hydrolysis antioxidant capacity of its internal relations, the rice residue efficient production of protein hydrolysis antioxidant peptides provide theoretical guidance, provide a theoretical basis for the comprehensive utilization of rice deep processing byproducts rice residue protein.