中文摘要：

研究不同强度的超声波（150、300、450 W）在12 min和24 min处理时间下对大豆分离蛋白-磷脂相互作用程度的影响,同时揭示了复合体系功能性质随超声条件变化的规律。通过圆二色光谱、粒径分布、ζ-电位、溶解度以及乳化性指标的测定发现：当超声波处理时间为12 min时,中功率（300 W）超声波对大豆分离蛋白-磷脂复合体系的影响最大,α-螺旋含量降低,溶解度及乳化性较高。当超声时间延长至24 min时,低功率（150 W）超声波会明显增加大豆分离蛋白-磷脂复合体系的乳化性,同时体积平均粒径由未超声样品的16.87 μm减小至6.49 μm、ζ-电位绝对值增大,α-螺旋含量降低至7.6%,溶液分散均匀且性质稳定。但随着超声波功率的进一步增大,蛋白质发生不溶性聚集,导致其与磷脂间的相互作用变弱,复合体系的各项功能性质随之下降。这表明超声波处理会影响大豆分离蛋白与磷脂相互作用的程度,适宜强度的超声波处理有利于复合体系功能性质的提升。

英文摘要：

Ultrasonic treatments with different power（150, 300 and 450 W） for different durations（12 and 24 min） were applied on soybean protein isolate-phospholipid system to evaluate their effects on the composite system. Functional properties of the composite system as a function of ultrasonic conditions were explored at the same time. Circular dichroism spectrum, particle size distribution, Zeta-potential, solubility and emulsibility were determined. The results showed that ultrasonic treatment for 12 min with medium power（300 W） had the greatest impact on the composite system. The content of α-helix decreased obviously, and the solubility and emulsibility were higher than those of the untreated sample. When the ultrasonic treatment time increased to 24 min, low ultrasonic power could significantly increase emulsifying properties of the system. Particle size decreased from 16.87 μm to 6.49 μm and the absolute value of Zeta-potential increased. The content of α-helix decreased to 7.6%, and the solution had homogeneous distribution and stable properties. But various functional properties of the composite system reduced when ultrasonic power increased to 450 W due to the occurrence of insoluble protein aggregate. Thus, the interaction between soybean protein isolate and lecithin became weaker, indicating that ultrasonication had an impact on soybean protein isolate-phospholipid interaction. Ultrasonic processing at appropriate intensity would promote the functional properties of the composite system.