低频超声对豆粕蛋白浸出率及SPI功能特性的影响

Effects of Ultrasonification on Protein Extraction of Defatted Soy Flakes and Functionality of SPI

研究低频超声对脱脂豆粕蛋白浸出率及大豆分离蛋白 (SPI)功能特性的影响 .实验结果表明 :低频超声可有效提高脱脂豆粕的蛋白浸出率 ,用 30 0W、12Hz低频超声处理 8min ,高温和低温脱脂豆粕的蛋白浸出率分别为 73.4 3%和 90 .2 8%,而 4 5℃加热搅拌提取 1h ,高温和低温脱脂豆粕的蛋白质浸出率仅为 4 9.5 8%和 6 6 .5 4%;SDS PAGE和GPC分析显示 ,低频超声主要影响大豆的 7S蛋白组分 ,并使其发生聚合 ;低频超声还能明显改善SPI的功能特性 ,SPI溶液经过低频超声处理 ,乳化活性增加 ,但粘度下降 .

The ultrasonic extraction of soy protein from defatted soy flakes and the effects of ultrasonic treatment on the functionality of soy protein isolates (SPI) were studied. The results show that the ultrasonic treatment could obviously increase the extraction of protein from different denatured defatted soy flakes. The protein extraction of defatted soy flakes and white flakes with ultrasonic treatment at 300W and 12kHz for 8min were 73.43% and 90.28% respectively,but only 49.58% and 66.54% with conventional stirring extraction at 45 ℃ for 1 h. SDS-PAGE and GPC analyses show that ultrasonic treatment mainly affects the 7S components of soy protein. The ultrasonic treatment can also improve the functionality of soy protein isolates (SPI) obviously. The emulsifying property of SPI increased while the viscosity decreased with ultrasonic treatment.