Phenolic compounds and antioxidant properties of breeding lines between the white and black rice

Advanced breeding lines made from the cross between the black and white rice as parents were collected to evaluate phenolic levels and antioxidant properties. No free phenolic acid was found in the soluble fraction, while p-coumaric acid, ferulic acid, isoferulic acid and vanillic acid were identified in insoluble bound fractions. Of noteworthy, is isoferulic acid which has rarely been reported to occur in cereal grains. Phenolic dehydrodimers were only observed in the insoluble bound fractions, which mainly consisted of 8-5′-coupled diferulic acids and 5-5′-coupled diferulic acids. Cyanidin 3-glucoside, peonidin 3-glucoside and cyanidin occurred in black and some light-purple rice samples. The breeding line YF53 has the highest total phenolic content (23.3 mg ferulic acid equiv./g), total anthocyanin content (2.07 mg cyanidin-3-glu equiv./g), and antioxidant activities. The results indicate that it is possible to develop advanced breeding lines for improvement of the phenolic profiles and antioxidant capacity with high yield.