Study On The Antioxidative Activity And Application Of Rice Protein Peptides

The solubility of rice protein is bad because of it includes the massive prolamine, and this has limited its application in the food industry. Therefore, the functional nature (such as solubility, emulsibility and water retention property) of the rice protein will be enhanced through the rice protein hydrolyzing by Alcalase. Simultaneously, it will be able to obtain the function peptides, such as Antioxidative Peptides or Agiotensin I-Converting(ACE) Inhibitory Peptides. And then enhanced the application value of the rice protein in food industry.The main objective here was to study the optimum hydrolysis condition of preparing rice protein peptides with high antioxidative activity, separation and purification of rice protein peptides, the composition of amino acid and the inhibitory effects on lipid oxidation in fried meat pellets.The optimum hydrolyzing condition of rice protein and antioxidant activity of rice protein hydrolysates in a liposome system were studied in this paper. Rice protein was hydrolyzed by Alcalase, and was hydrolyzed at different substrate concentration, reaction temperature, [E]/[S]and pH with the different time. Hydrolysate was used and researched inhibition of peroxide formation in a liposome-oxidizing system. Hydrolyzing condition was chosen by DH and TBARS value. The result of optimization of hydrolyzing condition of rice protein: rice protein was hydrolyzed for 5h by alcalase, substrate concentration for 5% and [E]/[S] for 1200U/g, pH for 9.0, reaction temperature for 55℃.The result showed that the antioxidative activity of the rice protein peptides did not become strong with DH increasing, but it had the strongest antioxidative activity under some specific value. The reducing power and radical scavenging activity of rice protein peptides(5h)were measured, the results showed that the antioxidative activity of rice protein peptides was strong.Rice protein peptides were added in lard, and the PV value was as director method by hot-temperature(60℃).The result showed that the more rice protein peptides concentration the stronger antioxidative activity. 3% rice protein peptides were added in fried pork pellets pocessed clearly effect for different concentrations.Rice protein peptides were separated and purified by sephadex G-25, and the mean molecular weight was determined. The result showed that the distribution of peptides was continual, and the antioxidative activity of the peptides which molecular weight is from 130.6 to 1155.6 shows good effect. The rice protein peptides at a 1.0%,1.5%,2.0%,3.0% concentration level were added to fried pork pellets, during the storage period, TBARS and Chromatic aberration were measured on fried pork patties, and compared with the treatment were added BHA. The results showed that the treatments added rice protein peptides had inhibitory effects on lipid oxidation.