超声处理对芸豆蛋白理化性质及抗氧化能力的影响

本试验以脱脂芸豆蛋白为原料，利用溶解度、乳化性以及总抗氧化能力等指标分析不同超声条件对芸豆蛋白理化性质及抗氧化能力的影响。结果表明:与未处理组相比，当超声时间20 min、功率400 W时，芸豆蛋白的水解度与溶解度达到最大值，分别由3.34%增加至20.10%，56.83%增加至79.63%；超声处理后芸豆蛋白起泡性及起泡稳定性显著增强（P<0.05），当超声时间10 min、功率400 W时分别达到最大值162.81%、72.94%；与未处理组相比，当超声时间10 min、功率400 W时乳化性最佳，增加了2.82 m2/g，超声功率不变，时间延长至20 min乳化稳定性最强，增加了18.95%；超声处理使芸豆蛋白的游离巯基含量显著提高（P<0.05），二硫键含量显著减少（P<0.05）；总抗氧化能力在超声时间30 min，功率160 W时抗氧化能力最好（674.63 U/mL），DPPH自由基清除能力与Fe离子还原能力在超声时间10 min、功率400 W时达到最大值，分别提高了38.96%、17.84%。综上，超声处理能够显著改善芸豆蛋白理化性质，提高其抗氧化能力。

Effects of Ultrasound Treatment on Physicochemical Properties and Antioxidant Ability of Kidney Bean Protein

In this experiment, degreased kidney bean protein was used as raw material. The effects of different ultrasonic conditions on the physicochemical properties and antioxidant capacity of kidney bean protein were analyzed by solubility, emulsification and total antioxidant capacity. The results showed that compared with the untreated group, when the ultrasonic time was 20 min and the power was 400 W, the hydrolysis degree and solubility of kidney bean protein reached the maximum value, which increased from 3.34% to 20.10% and 56.83% to 79.63%, respectively. Foamability and foamability stability of kidney bean protein were significantly enhanced after ultrasonic treatment (P<0.05), when the ultrasonic time was 10 min and the power was 400 W, the maximum value was 162.81%, 72.94%. Compared with the untreated group, when the ultrasonic time was 10 min and the power was 400 W, the emulsification was the strongest, increasing by 2.82 m2/g. When the ultrasonic power remained unchanged, the time was extended to 20 min, the emulsification stability increased by 18.95%. Ultrasonic treatment significantly increased the content of free sulfhydryl group and decreased the content of disulfide bond in kidney bean protein (P<0.05). The total antioxidant capacity (674.63 U/mL) was the best when the ultrasonic time was 30 min and the power was 160 W. The scavenging ability of DPPH free radical and reducing ability of Fe ion reached the maximum value when ultrasonic time was 10 min and ultrasonic power was 400 W, which were increased by 38.96% and 17.84%, respectively. In summary, ultrasound treatment could significantly improve the physical and chemical properties of kidney bean protein and enhance its antioxidant capacity.