Limited Enzymic Hydrolysis of Broad Bean Vicilin and Legumin: Conformational and Functional Changes

摘要

Conformational and functional changes in Broad bean vicilin (7S globulin) and le-gumin (11S globulin) following limited papain hydrolysis were examined using fluorescence probe techniques, circular dichroism spectroscopy, laser scattering measurements, as well as determination of emulsifying activity index (EAI) and emulsifying stability index (ESI). The surface hydrophobicity of legumin decreased from 360 to 38. Contrary to previous findings, circular dichroism spectroscopy studies revealed that legumin exhibited a lower percentage of beta - sheet secondary structure, whereas vicilin exhibited a lower percentage of helical structure after hydrolysis. The particle size of legumin increased however vicilin decreased after hydrolysis. This result showed that the legumin hydrolysate maybe has a re - aggregation in the solution. Best emulsifying properties were attained after a rather low papain hydrolysis (about 8% DH to legumin and 6% to vicilin). Further hydrolysis unpaired the emulsifying properties of Broad bean legumin and vicilin.