Effect of Drying Process of Malting Rice on Enzymatic Activity

Abstract

This study investigated the effect of drying on α-amylase,  β-amylase, and protease activities and diastase power in rice malt. Common rice (Oryza sativa) was soaked at 30°C for 50 hours, germinated at 30°C for 7 days and dried at 50°C for 24 h. The change in moisture content and enzymatic activities was determined throughout the drying period. Results showed that moisture content  reduced from 42.1% to 3.9% after 24 hours drying at 50°C. Maximum activity of protease,  diastase power, α-amylase and β-amylase occurred after 12, 10, 12, and 6 hours of drying, respectively. Proteolytic activity in rice malt when compared to the barley malt control was almost similar. All enzymatic activities were found to decrease during the drying process. Although amylolytic activity was low in malted rice, rice malt shows potential as an ingredient for the brewing and cereal industry.