超声处理对杜仲籽仁蛋白结构及理化特性的影响Effect of ultrasound treatment on structure and physicochemical properties of Eucommia ulmoides seed kernel protein

旨在为杜仲籽仁蛋白的开发与应用提供参考，以杜仲籽仁粕为原料，采用碱溶酸沉法提取蛋白，采用500 W、35 kHz超声波对杜仲籽仁蛋白处理不同的时间(0、10、20、30 min和40 min)，探究超声处理对杜仲籽仁蛋白微观结构、理化特性（粒径、Zeta-电位、内源荧光光谱、溶解性、持水性、持油性、起泡性、起泡稳定性、乳化性、乳化稳定性）的影响。结果表明：超声处理可改变杜仲籽仁蛋白的微观结构、粒径、Zeta-电位和荧光强度；超声处理20 min时，杜仲籽仁蛋白溶解度达到7535%；超声处理10 min时，杜仲籽仁蛋白乳化性最大，达到72.12 m2/g；超声处理40 min时，杜仲籽仁蛋白持水性、持油性、起泡性和起泡稳定性最大，分别达到4.32 g/g、3.46 g/g、23.12%和21.12%。综上，超声处理可改善杜仲籽仁蛋白的持水性、持油性、起泡性、乳化性等功能特性。To provide reference for the development and application of Eucommia ulmoides seed kernel protein, the Eucommia ulmoides seed kernel meal was used as material, the protein was extracted with alkali solution and acid precipitation, and Eucommia ulmoides seed kernel protein was treated by ultrasound (500 W, 35 kHz) for different time (0, 10, 20, 30 min and 40 min). The effects of ultrasound treatment on Eucommia ulmoides seed kernel protein′s microstructure and physicochemical properties (particle size, Zeta-potential, fluorescence spectrum, solubility, water holding capacity, oil holding capacity, foaming capacity, foam stability, emulsifying capacity, emulsifying stability) were studied.The results showed that ultrasound treatment could change microstructure, particle size, Zeta-potential and fluorescence intensity of Eucommia ulmoides seed kernel protein. When the ultrasound treatment time was 20 min, the solubility of Eucommia ulmoides seed kernel protein reached 75.35%. When the ultrasound treatment time was 10 min, the emulsifying capacity of Eucommia ulmoides seed kernel protein was the highest, reaching 72.12 m2/g. When the ultrasound treatment time was 40 min, the water holding capacity, oil holding capacity,foaming capacity and foam stability of Eucommia ulmoides seed kernel protein were the largest, reaching 4.32 g/g, 3.46 g/g, 23.12% and 21.12%, respectively. In summary, ultrasound treatment can improve the functional characteristics of Eucommia ulmoides seed kernel protein,such as water holding capacity, oil holding capacity, foaming capacity and emulsifying capacity.