Comparison Of The Composition Of Glutinous Rice Bran And Rice Bran And The Preparation Technology Of Its Antioxidant Peptides

China is a big agricultural country, has abundant rice resources, and the annual output tops the world. Glutinous rice belongs to Poaceae Oryza, which is a variant of sticky rice. Glutinous rice is featured by wide variety and comprehensive nutrition, which is a body building and warm food. Rice and glutinous rice are essential household foods. According to the relevant information, the planting area of glutinous rice in China is approximately 3%~5% of the total rice planting area, yield per Mu reaches 450 kg, and yield per unit is 6750~8250kg/hm. Rice planting area in China is about 440 million mu, glutinous rice planting area is about 1320~2200 acres, and the yield is about 6~10 billion kg. [1] Glutinous rice bran is also called “rice meal” bran, which is 6% of the glutinous rice weight, yet its nutrition accounts for about 60% of glutinous rice nutrition. At present, China lacks inadequate processing technology and utilization technology for rice bran and glutinous rice bran, mostly are used as feed, only about 10% of the rice bran are used to produce oil and extract part of the beneficial substances. As a result, this effective resource cannot be fully utilized, resulting in huge waste. Therefore, United Nations Industrial Development Organization calls it as a underutilized raw material.This paper adopts rice bran as a control, makes a comparative study of the glutinous rice bran, including the component analysis of glutinous rice bran, super-critical CO2 extraction and ingredient analysis of glutinous rice bran oil, preparation process of glutinous rice bran antioxidant peptides and free radical scavenging ability, aims to provide a reliable theoretical basis for the development and utilization of glutinous rice bran. The main research is as follows:(1) After analyzing and comparing the nutrients of glutinous rice bran and rice bran, ingredients and contents of minerals, vitamins and amino acid, the moisture and fat content of glutinous rice bran are similar to rice bran, its protein and total dietary fiber contents are lower than the contents of rice bran, its ash, crude fiber, soluble polysaccharide contents are higher than rice bran; calcium, potassium and magnesium of glutinous rice bran are significantly higher than rice bran, and iron, zinc and selenium content s are less than rice bran; vitamin E, vitamin B1 and vitamin B2 contents of glutinous rice bran are significantly higher than rice bran; both amino acids ingredients are identical, various amino acid contents of glutinous rice bran are significantly higher than the corresponding amino acid contents of rice bran, the essential amino acid of glutinous rice bran reaches 4.174%, while rice bran contains essential amino acids of 3.547 %. It indicates that the glutinous rice bran and rice bran have slightly different natures.(2) This paper takes the oil yield as an index, and uses the super-critical CO2 fluid to extract the fat of glutinous rice bran and rice bran. The single factor experiment results show that the extraction pressure is 35 MPa, extraction temperature 45 ℃, extraction time 2h, CO2 fluid flow 70kg/h, and the oil yield rate of glutinous rice bran and rice bran are the highest, which are respectively 12.95% and 13.22%. Fatty acid ingredients of glutinous rice bran oil and rice bran are identical. Among the essential fatty acids, palmitic acid and oleic acid contents of glutinous rice bran and rice oil are respectively greater than the contents of rice bran oil and rice oil, and linoleic acid contents are respectively less than the contents of rice bran and rice. It indicates that the nutritional values of glutinous rice bran oil and rice bran oil are slightly different.(3) This paper takes the neutral protease enzyme as the hydrolysis enzyme, extracts the antioxidant peptides, adopts the reducing power of antioxidant peptides as an index, studies the effects of glutinous rice protein substrate concentration, enzyme dosage, pH, reaction temperature, reaction time and other factors on glutinous rice bran antioxidant peptides preparation, and optimizes the preparation process by adopting single factor experiment and orthogonal experiment. The results show that the optimum preparation conditions for glutinous rice bran antioxidant peptide is 4% glutinous rice protein substrate concentration, E]/[S] 2%, pH 7, enzymolysis temperature 40℃, and enzymatic hydrolysis time 6h; in this condition, the scavenging abilities of prepared glutinous rice bran antioxidant peptide over hydroxyl radical and superoxide anion radical are significantly better than the rice bran antioxidant peptide, and there is a certain dose-effect relationship.