The molecular flexibility and emulsifying properties of soy protein isolate (SPI) and soy protein isolate-glucose (SPI-G) conjugates after ultrasonic treatment were studied. The results showed that the degree of Maillard reaction increased significantly with the increase of ultrasonic intensity (P < 0.05), and the flexibility of SPI-G conjugates increased significantly (P < 0.05). After ultrasonic treatment, the particle size of the protein was reduced and the protein structure became looser. The analysis of the fluorescence and FT-IR spectra showed that both the ultrasonic treatment and Maillard reaction process could stretch the structure and increase the flexibility of SPI molecules. Correlation analysis indicated that the molecular flexibility of SPI and SPI-G conjugates treatment after ultrasonic treatment was significantly correlated with protein emulsification activity and emulsion stability.

研究了超声处理后大豆分离蛋白（SPI）和大豆分离蛋白-葡萄糖（SPI-G）结合物的分子柔性和乳化性能。结果表明，随着超声强度的增加，美拉德反应程度显着增加（P <0.05），而SPI-G共轭物的柔韧性显着增加（P <0.05）。超声处理后，蛋白质的粒径减小，蛋白质结构变得更松散。荧光和FT-IR光谱分析表明，超声处理和美拉德反应过程均可以拉伸结构并增加SPI分子的柔性。