HEAT-INDUCED GELATION OF PEA (PISUM-SATIVUM) MIXED GLOBULINS, VICILIN AND LEGUMIN

Mixed globulins (MG) were extracted from ground dry peas (Pisum sativum, B-160) with 0.5M NaCl, 50 mM potassium phosphate, pH 7.2, and isolated by precipitation at pH 4.5. Crude vicilin and legumin were fractionated from the MG by dialysis against 0.2M NaCl, pH 4.8, and centrifugation, then further purified using DEAE-cellulose chromatography. Conditions for maximum gel hardness of heat induced MG gel, as determined with an Instron Universal Testing Machine, were heating for 20 min at pH 7.1 at 87 degrees C. Purified vicilin, but not legumin, formed heat induced gels. The relationship was linear between protein (globulin) concentration and log gel hardness. At all protein concentrations studied, as proportion of legumin decreased, gel hardness increased.