Abstract:To investigate the influence of chlorogenic acid on the physicochemical properties and structural characteristics of soy protein under microwave conditions, microwave was used to analyze the changes in solubility, water holding capacity, emulsifying capacity, oil holding capacity, and foaming capacity of soy protein chlorogenic acid complexes (SPCA). The crystal structure was characterized and the particle morphology was observed. The results showed that the solubility, oil retention and foaming ability of soybean protein decreased to 290.55 μg/mL, 269.70% and 143.67% respectively, while the foam stability and emulsifying ability increased to 21.67% and 43.00% respectively when chlorogenic acid was added. The solubility, oil retention, foam stability and emulsification of SPCA can be increased to 368.00 μg/mL, 402.51%, 156.30% and 52.67%, while the water retention decreased to 432.88% after microwave treatment at 700 W for 5 min. The structural analysis of SPCA showed a decrease in diffraction peak intensity and crystallinity, with the appearance of new diffraction peaks and a significant reduction in particle size. The surface was rough and uneven, with the structure curling inward and significantly affected by microwave action. The conclusion is that microwave can offset the decrease in protein solubility and oil holding caused by the addition of polyphenols, and adding chlorogenic acid under microwave conditions can more effectively improve the foaming and emulsifying properties of soy protein.