Effects of limited proteolysis and high-pressure homogenisation on structural and functional characteristics of glycinin

Glycinin was treated by limited proteolysis and/or high-pressure homogenisation in this work. The combined treatments significantly improved the solubility of glycinin, especially in acidic aqueous solution. Moreover, the modified glycinin had better emulsification capability and lower surface hydrophobicity. Electrophoresis analysis indicated more aggregates were formed after above treatments. But the laser scanning test showed the particle size of glycinin decreased. Compared with limited proteolysis, the combined treatments further increased the storage modulus and postponed the onset of glycinin gelation. The results of scanning electron microscopy showed that a fibrous curly structure was present in native glycinin. It was not found in modified glycinins. High-pressure homogenisation slightly shortened the onset of glycinin gelation, while limited proteolysis apparently postponed this behaviour. All the treatments formed weaker gels than native glycinin.