The Antioxidative Soybean Peptide Pruduced By Enzymic Method And It's Antioxidative Active Preserve Technique

The research on bioactive peptide is a popular subject in nutrition nowdays because it has high nutritional value, functional activities and economic value .This experiment contrasted the hydrolytic effect of SPI among the six different proteolytic ferments and choosed the Alcalase basic protein which can produce the best antioxygen peptide, the optimization technology condition of hydrolytic SPI was determined by orthogonality experimentation: concentration of substrate 7.0%, the dosis of enzyme 9000U/g substrate, temperature 52.5℃, pH 8.5,the reaction time 5h..In the optimum condition,the degree of hydrolysis of protein was 24.28% ,NSI 95.7% ,the protein content was 43.5mg/mL and the recovery rate of protein was 71.2%. The antioxygen activity of hydrolysis product was researched from the capability of cleaning OH·, the capability of cleaning O₂^-·and the capability of inhibiting ROO·.After hydrolyzing of 5h ,the OH·inhibition ratio of the production was 36.43%, the activity of cleaning O₂^-·of the production was 317.73U/g, the ROO·inhibition ratio of the production was 46.24%.The hydrolysis products abstracted by the ultrafiltration were classified into three parts: above2000D,between 2000D and 5000D ,below 2000D ,which were cut off by 5000 D and 2000D ultrafiltration membrane .Then comparing the antioxdative activity of the three compositions,the result showed that the antioxidative peptide of the composition of which molecular weight was less than 2000D was the most powerful. So 2000D ultrafiltration membrane was choosed in the abstraction. Above monofactorial found, the response experiment of 4 factors (pressure, pH, temperature, time) and 3 levels was designed by the response value of the film percolation flux. The best ultrafiltrate condition gained by the response experimentation was that : pressure 0.24MPa ,pH 6.47, temperature 44.8℃, time 109.6min. Under the optimal condition ,the membrance flux was 28.62 L/(m2h). The antioxdative activity had enhanced after ultrafiltration, the activity of cleaning O₂^-·increased from 317.73U/g to 387.9U/g.The activity of antioxygen bean peptide that was gained and has higher activity was protected by microencapsulation. Microballoons of bean antioxygen peptide were prepared by complex coacervation and multi-phase emulsion in this experiment. The optimal technology condition of complex coacervation : concentration of chitosan 0.8%,the ratio of acacia and peptide of core material 8:1, temperature of sacculation45℃, pH 4.75. The ratio of embedment of microcapsule gained was 64.0%, dosage was 11.78%.The best technology condition of multi-phase emulsion: Sodium Alginate 2.5%, Calcium chloride 8.0%, the velocity of emulsification 8000rpm, concentration of emulsifier 8.0%, The ratio of embedment of microcapsule of soybean antioxidative peptide gained was 73.65%, dosage was 13.2%.The vitro test certified: the release rate of two kinds of microballoons was both low in the gastric fluid. These microballoons continue to release for the purpose of delayed release in the intestinal juice. Comparing the activity of antioxygen embedment with not embedment, embedded activity had a little loss. The test showed that the activity of antioxygen peptide was protected by microencapsulation..