The effect of germination on GABA content, chemical composition, total phenolics content and antioxidant capacity of Thai waxy paddy rice

Abstract

The changes were studied in the GABA content (gamma aminobutyric acid), chemical composition, total phenolics content and antioxidant capacity from the germination process of Thai waxy paddy rice (RD6). The paddy rice was soaked to about 33% wet basis moisture content and then germinated in the cabinet incubator (28-30°C) for 0, 12, 24, 36, 48 and 60 h. Embryos were cut to determine the GABA content, and the germinated paddy rice was dried at 50°C using a tray dryer, dehusked and ground for analysis. It was found that the germination process significantly (p<0.05) increased GABA, dietary fiber, total phenolics content and antioxidant capacity, while the fat, protein, starch and amylose content trended to decrease slightly. There was little change in the early stage of germination and then a marked increase after 36 h. For the GABA content after soaking, it gradually increased from 80 to 220 mg/100 g embryo fresh weight from 12 to 60 h. Based on the results, germinated paddy rice can be considered as an alternative source of GABA and of dietary fiber content with high total phenolics content and high antioxidant capacity.