Proteases from Calotropis gigantea stem, leaf and calli as milk coagulant source

Abstract

Abstract Background: Universal demand for cheese keeps the search for appropriate enzymes from plants mimicking animal rennet action in scientific focus. Objective: To associate distribution of milk clotting potential and profile of whole/κ-casein hydrolysis by Calotropis gigantea stem, leaf and respective calli crude enzymes (CE). Materials and methods: Milk clotting activity and index were assayed for CE. Caseinolytic activity (CA) was evaluated spectrophotometrically. 0.5 CA units of CE and Enzeco® were used for studying whole/κ-casein hydrolysis pattern by Tricine SDS-PAGE. Inhibition studies were performed for enzyme characterisation. Results: Traditionally propagated (TP) stem and its callus CE exhibited high specific milk clotting activity (1297.30±0.2 U/mg of protein and 926.74±44.13 U/mg of protein, respectively) and milk clotting index (103.562±1.162 and 79.365±4.93, respectively). Comparison of whole casein hydrolytic pattern by 0.5 CA units of CE revealed closer resemblance between leaf callus and Enzeco®. However, κ-casein specificity analysis revealed TP leaf to be closely mimicking the performance by Enzeco®. Conclusion: Study suggests CE from TP leaf to be a potential vegetable coagulant to work as an effective and low-cost milk clotting mediator in cheese industry.