超声处理对大豆分离蛋白流变学性质的影响

Effect of Ultrasonic Treatment on the Rheological Property of Soybean Isolated Protein

研究超声对大豆分离蛋白(SPI)溶液超声流变学性质的影响。实验结果表明,超声对SPI溶液的表观粘度有显著下降作用,10.0%和12.5%SPI溶液表观粘度经25kHz、400W超声处理20min后,两溶液的粘度分别降至对照样的3.2%和6.5%。流态指数n值分别由0.66、0.44增加到0.81和0.78。超声处理大豆分离蛋白样与对照相比,粘弹性都下降约一个数量级,相对粘弹性tanδ变化较小,超声处理对储能模量G′的弱化作用低于损耗模量G″的弱化作用。超声处理使大豆蛋白溶液Braband粘度明显降低。

The changes of rheological property of soybean protein isolated （SPI） after ultrasonic treatment were studied. According to the results, after 20min treatment with 25kHz and 400W ultrasonic treatment, the apparent viscosity of 10.0% and 12.5% were reduced to 3.2% and 6.5% of the control respectively. The flow behavior indexes were increased to 0.8 land 0.78, from the control as 0.66 and 0.44 respectively. The storage modulus G ＇ and the loss modulus G＇＇ were lowered to ten percent of the control after sonicafion. Sonication effect would lower G＇＇ value more than lowering of G＇ value. However sonication had little effect on the tan δ value. The Braband viscosity was also reduced markedly after ultrasonic treatment.