Effect of Pre-Germination Time on Amino Acid Profile and Gamma Amino Butyric Acid (GABA) Contents in Different Varieties of Malaysian Brown Rice

Abstract

Eighteen varieties of Malaysian brown rice were evaluated for their crude protein, total glutamic acid, and gamma amino butyric acid contents after pre-germination at different times. The crude protein and total glutamic acid content increased significantly in all the varieties after pre-germination. Gamma amino butyric acid content increased dramatically with time during the pre-germination process. A significant (p < 0.05) positive correlation was observed between protein, glutamic acid, and gamma amino butyric acid contents before and after pre-germination. The brown rice varieties containing higher glutamic acid and/or protein content before the pre-germination process provided more gamma amino butyric acid content during pre-germination.

Keywords:

• Brown rice
• Unpolished rice
• Pre-Germination
• Functional compounds
• γ-Oryzanol

ACKNOWLEDGMENTS

The authors wish to express their sincere gratitude to Dr. Boo Huey Chern for her kind cooperation. This work was fully supported by the GABA biosynthesis project, the Ministry of Education, Malaysia.