Effects of Different Enzyme Treatments on Structure and Stability of Proteins Extracted from Soybean Emulsion

LI Yang;LI Hong;QI Baokun;XIE Fengying;ZHONG Mingming;TAN Zheng;College of Food Science,Northeast Agricultural University;

soybean emulsion;;enzyme;;enzyme-assisted;;stability

The enzyme-assisted extracted soy emulsion was taken as object to explore the different biological enzyme treatments of emulsion protein structure and stability(Protex 6 L, Acalase 2. 4 L lysophospholipase,Phospholipase A2 and Phospholipase D). It was found that the emulsions were treated with two kinds of proteases and three phospholipases respectively,the particle size distribution,Zeta potential,microscopic observation,infrared spectrum and fluorescence spectrum were known,the results showed that the stratification coefficient and yield of free oil in decreasing trend were lysophospholipase,Acalase 2. 4 L,Protex 6 L,phospholipase D,and phospholipase A2. Using lysophospholipase hydrolysis,the Zeta potential and the average particle size were increased significantly. The microstructure of the emulsion was found that the oil droplets were accumulated obviously,which was consistent with the results of potential and particle size. The protein secondary structure of the emulsion after the enzyme treatment,the α-helix content was decreased and the random coil content was increased,and α-helix content of the lowest,random coil content was the highest by using lysophospholipase. All samples by protease and phospholipase treatment,the fluorescence intensity was reduced,the fluorescence intensity of the protein was the lowest in the emulsion after lysophospholipase treatment. The content of PA was increased and the PC and PE were decreased by using lysophospholipase, phospholipase A2 and phospholipase D.