Effect of germination in the form of paddy rice and brown rice on their phytic acid, GABA, γ-oryzanol, phenolics, flavonoids and antioxidant capacity

Abstract

This study investigated the effect of paddy rice and brown rice germination on their phytic acid, phytase, GABA, γ-oryzanol, phenolics, flavonoids and antioxidant capacity. The GABA content and phytase activity in the rice germinated in the form of paddy (GP) were respectively lower than those in the rice germinated in the form of brown rice (GBR), and the level of phytic acid in GP was higher than that in GBR during germination processes from 18 h to 72 h. However, the contents of total γ-oryzanol, free phenolic, total phenolic, free flavonoid and total flavonoid in GP were higher than those in GBR during germination processes (18-72 h). The antioxidant activities of DPPH and T-AOC in GP were respectively higher than those in the GBR during germination processes (18-72 h). These results demonstrated that GP produced more γ-oryzanol, phenolics, flavonoids content and higher antioxidant activities, but less GABA content than those in GBR. This work might be useful for the specific aim of choosing germination ways and for the development of wholegrain foods.

Keywords: Antioxidant capacity; GABA; Germination in the form of paddy and brown rice; Phenolic; Phytic acid; γ-oryzanol.