Studies on the effects of enzymatic hydrolysis on functional and physico-chemical properties of arachin

Arachin, the major protein fraction isolated from groundnut (Arachis hypogaea L.) was enzymatically modified to get desired degree of hydrolysis (DH) using papain, alcalase and fungal protease. The measured DH of arachin obtained with different proteases under optimum conditions suggested that the effectiveness followed the order fungal protease>papain>alcalase. The solubility in pH range 4–4.5 was 14–16% with a low DH compared to 55–60% with high DH. Emulsification capacity of arachin improved with low DH; papain was more effective compared to alcalase and fungal protease. The foam capacity of alcalase modified arachin with low DH was remarkably high compared to papain and alcalase modified arachin. Limited proteolysis did not bring about significant improvement in foam stability. However, extensive hydrolysis of arachin resulted in remarkable reduction in emulsification, foaming capacity and stability. The gel electrophoretic analysis of modified arachin suggested that the low molecular weight subunits were resistant to enzymatic attack initially and disappeared after 1 h hydrolysis.