INFLUENCE OF CULTIVAR AND GERMINATION CONDITIONS ON PROTEOLYTIC ACTIVITIES IN SORGHUM MALT

The effects of cultivar and germination conditions on proteinase and carboxypeptidase activities in sorghum malt were investigated using enzyme assays based on kafirin, the sorghum prolamin, as substrate. When different sorghum cultivars grown under identical environmental conditions were malted under identical conditions, the proteinase and carboxypeptidase activities of the various malts both differed significantly. This indicates that the activities of these enzymes are cultivar related. Steeping sorghum grain resulted in no significant change in proteinase or carboxypeptidase activity. Proteinase activity increased only moderately with germination time, up to a maximum at 4 days. Neither germination temperature (24-32-degrees-C) nor moisture affected proteinase activity. In contrast, there was a large increase in carboxypeptidase activity with germination time up to 4 days and both germination temperature and moisture affected carboxypeptidase activity.