Antioxidant activities and sensory properties of rice bran with marigold tea

Abstract

Bioactive compounds and antioxidant activities of the rice bran with marigold tea formulated by mixing different proportions of rice bran and marigold were investigated. Comparative results of sensory evaluation were conducted by Thai panelists (n=30) and Austrian panelists (n=30), respectively. The results showed that rice bran with marigold tea had high values of antioxidant activities as measured by DPPH radical scavenging (95-97%), ferric reducing/antioxidant power (FRAP) (80-84 μmol FeSO4/g dry sample), total phenolic content (TPC) (29-49 mgGAE/g dry sample), and total flavonoids content (TFC) (61-69 mgRE/g dry sample). The predominant phenolic acids in rice bran with marigold tea were gallic, ferulic and sinapic acid and the main flavonoids were quercetin and rutin. A proportion of 50% rice bran: 50% marigold showed the highest sensory scores of all formulas for Thai panelists (n=30), while Austrian panelists have evaluated a proportion of 30% rice bran: 70% marigold with the highest score. Austrian panelists seemed to dislike the odor of the product when the proportion of rice bran was increased. This study demonstrated that rice bran with marigold tea could be considered as alternative beverage for health benefits. However the optimum formula was dependent on consumers’ preference.