Changes in Glutamate Decarboxylase Activity and Distribution during Storage of Rice

Abstract

In this study, changes in glutamate decarboxylase (GAD) activity and distribution during storage of rice were examined. GAD activity of brown rice was gradually decreased to 30% during 12 months of storage at 15°C. It was suggested that moisture content and storage temperature influenced the changes in GAD activity. The GAD activity of rice germ was the highest, and the powdered outer layer of brown rice (100-94%) showed 77% of the GAD activity of rice germ. The GAD activity was low in the endosperm, with the largest portion of GAD activity observed in the rice bran.