Abstract:

Changes in activities of various enzymes in barley malt during drying process were investigated. The results showed that the activities of α-and β -amylases increased firstly and then sharply decreased over the whole drying process of 20 h. The activities of carboxypeptidase and aminopeptidase increased gradually to their maximum values during the earlier drying process (at 5 h and 7.5 h, respectively) and then presented little decreases. POD was steadier than the other oxido-reductases and decreased significantly in half of period of languish, but this change was smaller in period of kilning. However, PPO activity was sensitive to heating with steady decrease in period of languish and was destroyed significantly in period of kilning, which in dried malt was 62% of that in green malt. β-Glucanase showed more resistant to heating, and almost no changes in its activity were observed with drying time extending after reaching the plateau at 2.5 h.

Key words: malt, drying, enzymatic activity