Abstract

Khaow-Mak is fermented food of rice, which contains a lot of nutrients and antioxidant bioactive compounds. Generally, Khaow-Mak is fermentedfrom cooked white glutinous rice. However, it canbe fermented with colored rice (black, purple and red pericarp colored grains) in orderto increase bioactive compounds and antioxidant performance. The study was conducted to investigate the chemical composition of Khaow-Mak extracts,total phenolic, flavonoid, and anthocyanin contents. The antioxidant activitieswere evaluated byusingthe scavenging towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP).The colored rice was collected from 16 local colored rice (red, black and purple) aroundThailand. The cooked rice was fermented with a starter (Look Pang) at room temperature for 5 days.  Fermented rice samples were extracted with 95 % ethanol for 24 hours.Dried crudeextracts were obtained using a rotary evaporator at 45 ^OC. The results showed that the content of bioactive compoundsof all colored rice were increased after fermenting time. Leum Phuaglutinous ricehad the highest contents of total phenolic (45.66±0.01mgGAE/g, flavonoid contents (39.35±0.07 mgRE/g) and anthocyanin contents (3.37 ± 0.21 mg/g). In addition, Leum Phuaglutinous riceshowed the hightest antioxidant activity of DPPH(EC₅₀ 0.364±0.02 mg/ml) and FRAP (28.018±0.01 mgFe(II)/g. These results potentiallysupport the use of local rice extracts as the active raw materialof functional food and/or cosmetics.

Keywords:Khaow-Mak, Colored Rice,Antioxidant