Effect of MTGase Conditions on Surface Hydrophobicity, Functional Properties and Solution Properties of Soybean 7S Globulin and Correlation Analysis of Its Indexes

Soybean 7S globulin was crosslinked by microbial transglutaminase(MTG)enzyme dosage(10,20,30,40,50 U/g),pH(3.0,4.0,5.0,6.0,7.0),temperature(40,45,50,55,60℃). The surface hydrophobicity of soybean 7S globulin was determined by ANS fluorescence probe method,and the average value was determined by Malvine particle size analyzer. The particle size,Zeta potential,emulsifying property and stability of soybean 7S globulin were also measured. The effect of single factor treatment on crosslinking was analyzed. The correlation between surface hydrophobicity of soybean 7S globulin and its emulsifying property,emulsifying stability and solution property were discussed. The results showed that the surface hydrophobicity,emulsifying property,emulsifying stability and average particle size were improved obviously when the enzyme was added at 20 U/g,pH7.0 and 55℃. The surface hydrophobicity,emulsifying property,emulsifying stability and average particle size of soybean 7S globulin were 1268.7,225.05 min,86.66% and 99.03 nm,respectively. Surface hydrophobicity was positively correlated with emulsifying property,but not with emulsifying stability;it was positively correlated with average particle size and negatively correlated with Zeta potential,with correlation coefficients of 0.718(P=0.003),0.304(P=0.270),0.860(P=0.005)and -0.727(P=0.02),respectively.