不同改性方法对花生浓缩蛋白结构及功能特性的影响

Effects of Modified Methods on Conformational and Functional Properties of Peanut Protein Concentrate

利用中性蛋白酶改性花生浓缩蛋白,并与超声波物理改性方法比较,测定了改性前后花生浓缩蛋白的溶解性、吸水性、吸油性、乳化性及乳化稳定性、起泡性及泡沫稳定性。结果发现,两种改性方法均对花生浓缩蛋白的溶解性及吸油性有较大改善,分别比改性前的浓缩蛋白提高了61.44%和161.70%,47.34%和165.03%,但酶解改性蛋白的乳化稳定性及超声波改性蛋白的起泡稳定性则分别比改性前降低了11.60%和32.96%。经电镜、电泳及圆二色谱对蛋白质显微结构、分子量大小和二级结构的变化规律进行了研究,探讨了花生浓缩蛋白改性机理。

Peanut protein concentrate（PPC） was modified by neutral protease, and compared with physical modification of the ultrasonic method. The solubility, water absorption, absorbing oil capacity, emulsibility and emulsification stability, foamability and foam stability of PPC were measured before and after the modification. It was found that both the two methods can make the solubility and absorbing oil capacity of PPC greatly improved, respectively. Compared with unmodified protein, concentrate increased by 61.44% and 161.70%, 47.34% and 165.03%; but the emulsification stability of enzyme modified protein and the foam stability of ultrasonic modified protein were lower than that before the modification by 11.60% and 32.96% respectively. By electron microscopy, electrophoresis and circular dichroism, the change rule of microstructure, molecular size and secondary structure were studied to discuss the modified mechanism of PPC.