Extraction Of Wheat Germ Protein In Wheat Germ And Antioxidant Capacity Of Wheat Germ Hydrolysates

wheat germ protein is a functional protein prepared from wheat germ, wheat germ protein contains a mass of bioactive amino acid sequence, the glutathione is a recognized active peptide which hydrolyzed by the wheat germ protein. It is the significant oxidative free radical scavenging agents, possessing the function of the antioxidation, the delaying senility, and the detoxification and improving the immunity. The purpose of this research was to define the crisis technology parameters of the purification of the wheat germ protein and the optimization of wheat germ antioxidant peptides by enzymatic hydrolysis, and research on the antioxidant and mechanism of wheat germ hydrolysates, to set up a technology condition of purification of the wheat germ protein.1.Extraction of wheat germ protein in wheat germ. This experiment selects means used enzyme and methods of Alkali-Solution and Acid-Isolation to prepare wheat germ protein, examining the amount ofα-amylase enzyme, temperature, pH on the purity of protein to get optimum parameters of extraction wheat germ protein in wheat germ. The result shows that the above three factors all have a more significant impact on protein purity. Optimal parameters is that theα-amylase addition 0.35%, temperature 66.7℃, extraction pH3.9, and in this conditions the purity of the protein has reached 99.17%. Preparing wheat germ protein with these two methods have a good result that process is simple, high protein purification, and suitable for industrial production.2.Optimization of technologic parameters of wheat germ antioxidant peptides by enzymatic hydrolysis. Wheat germ protein were hydrolyzed by using alcalase, neutrase and papain. The best hydrolyzed parameter were determined by Degree of hydrolysis, protein solubility and TBARS value with different enzyme, different hydrolyzed time, temperature and pH. Wheat germ protein hydrolysates possessed antioxidation, and the Optimal enzyme was neutrase for 5h. hydrolyzed temperature was 50℃,pH 7.0. The DH of neutrase-hydrolyzed wheat germ protein was 17.28%, it possessed strong antioxidation.3.Antioxidant and mechanism of wheat germ hydrolysates.Wheat germ protein was hydrolyzed for 0.5h—6h by neutral protease, degree of hydrolysis (DH) increased with hydrolysis time. And wheat germ protein hydrolysates′s DH, Thiobarbituric acid-reactive substance values, peroxide, Cu2+ chelation ability and radical-scavenging ability were mensurated. The result demonstrated that neutral protease-hydrolyzed wheat germ protein exhibited a stronger antioxidant activity than nonhydrolysised protein and 0.02% Vc, as indicated by peroxide and tbars values in a liposome-oxidizing system. And possessed strong Cu2+ chelation ability and radical-scavenging ability. Antioxidant mechanism of hydrolysates were analysised ,as what antioxidant index of nonhydrolysised wheat germ protein and hydrolysates with different concentration were the specific structure, type of peptides, ratio of different freed amino acids.