Effect of High-pressure Homogenization Combined with Chitosan Extraction on Structure and Function of Soy Protein in Whey Water

In this paper,soybean whey water was used as the raw material,which was treated by high-pressure homogenization synergistic chitosan interfacial recombination to efficiently recover residual soy protein. The effects of the technology on the structure and functional properties of the recovered protein were further studied. Results showed that,under the conditions as follows:The mass ratio of SPI-Chitosan mixture was 2:1,and high-pressure homogenization pressure was not higher than 90 MPa,the high-pressure homogenization synergistic chitosan treatment significantly(P<0.05)increased the protein recovery rate to 61.92%. Results of Raman spectroscopy showed that the contents of α-helix and β-sheet in soy protein isolate reduced,and the proportion of random coil content increased. The results of endogenous fluorescence spectrum showed that the fluorescence intensity and λ_max of the recovered protein increased,which indicated that the microenvironment of the protein structure and protein tryptophan residues in the mixed system changed. With the increasing of homogenization pressure,the solubility,emulsifying activity and emulsion stability of the recovered protein increased gradually,but the turbidity of the recovered protein solution gradually decreased. When the high-pressure homogenization pressure was higher than 90 MPa,the fluorescence intensity and λ_max of recovered protein decreased. This would provide theoretical guidance for the waster water treatment of industrial production of isolated soy protein,and by-product resource utilization.