Evaluation of plant proteases from medicinal plants as potential vegetable coagulant alternative

Abstract

With insights gained from studies on plant proteases, the current work aims in validating proteases from selected medicinal plants for their milk coagulation potential. Stem crude extracts (CE) from 30 plants were screened for their milk clotting (MCA), their caseinolytic activities (CA) and milk clotting index (MCI). Plant proteases with high MCA and MCI were partially purified using salt precipitation. Casein hydrolytic pattern of the partially purified protease was assayed through tricine- SDS PAGE. Commercial milk coagulants, rennin and Enzeco® were used as positive control. CE from thirty plants were screened and Wrightia tinctoria, Rauvolfia tetraphylla, Bacopa monnieri and Costus igneus were selected for partial purification based on their high milk clotting ability. High recovery of 76% and fold purification of ~3 was observed in W. tinctoria salt precipitated fraction with MCA. Comparable casein hydrolytic pattern was observed between CE of R. tetraphylla and C. igneus, salt precipitated extracts of W. tinctoria with commercial coagulants. The results open new avenues for researchers to explore these proteases as vegetable coagulant alternative.