Abstract:A soy β-conglycinin (7S) hydrolysate (7S-GE), obtained by the hydrolysis by the glutamyl endoproteinase (E.C. 3.4.21.19) at pH 7.5. The core region of 7S (7S-core) was prepared by filtered the 7S-GE through the micro-filter member with 10 kDa molecule cut-off. The emulsifying ability of 7S, 7S-GE and 7S-core were investigated using zeta-potential, droplet size and saturation surface load. The results showed that the emulsion formed by 7S-core had lower zeta-potential and significant higher droplet size and saturation surface load compared with the emulsion which formed by 7S and 7S-GE. The influence of pH, iron strength on the stability of the emulsions formed by 7S, 7S-GE and 7S-core were investigated. The results showed that the stability of the emulsion formed by 7S-core was decreased remarkably against the pH, iron strength. Higher creaming index and coalescence of oil droplet through the microscope were observed. This study demonstrated emulsifying ability and stability of 7S remarkably depended on the extension regions.
