HEAT SENSITIVITY, OPTIMUM PH AND CHANGES IN ACTIVITY OF SORGHUM PEROXIDASE DURING MALTING AND MASHING

Peroxidase activity was demonstrated in dry and germinating sorghum se eds. The specific activity increased about 14-fold during malting for a 96-hour period. On the average about 41% of peroxidase activity was located in the endosperm, and the remaining 56% in the acrospire and r ootlet of sorghum malt. The crude enzyme extract retained 77%, 17.5% a nd 7.6% of activity after heating at 60 degrees, 70 degrees and 80 deg rees C, respectively. More than 50% of the peroxidase activity in the finished malt survived mashing at 65 degrees C. Optimum activity was r ecorded at pH 5.5 which falls within the observed pH range of sorghum worts. The level of residual peroxidase activity in the wort differed with sorghum species.