摘要

The effect of soybean protein composition (different ratios of 7S globulin (β-conglycinin) and 11S globulin (glycinin)) on the emulsifying and interfacial properties of oil-in-water (O/W) emulsions was evaluated. The results indicated that manually extracted 7S and 11S globulins were in their native state. With increasing 11S content, the emulsifying activity index, absolute value of ζ-potential, protein concentration, content at the O/W interface, emulsifying activity, and stability were reduced, and the overall particle size distribution, droplet flocculation index, and droplet coalescence index of the emulsion were increased. According to the results of emulsifying properties, 7S globulin contributed more towards the overall emulsification ability of soybean proteins than the 11S globulin did. Electrophoresis images of interfacial proteins indicated that all subunits of the two globulins could be adsorbed at the O/W interface, and changes in the contents of all subunits were in accordance with the proportion of proteins in the sample. With increasing 11S content, the emulsion microstructure changed from a clear spherical shape into irregularly flocculated aggregates. In general, diffusion, adsorption, and rearrangement rates of the 11S globulin at O/W interface were higher than that of 7S globulin, and the rearrangement rates of all protein samples with different 11S contents at O/W interface were higher than the adsorption rates. These results suggest that emulsifying and interfacial adsorption properties of soybean globulins can be regulated to some extent by altering the protein composition.