Distribution of antioxidant compounds in the grain of the Mediterranean rice variety Ariete

Abstract

This work aimed at investigating the potential of the rice grain and its milling fractions (from clay and sandy soils) as sources of antioxidant compounds. Ten phenolic acids and four flavonoids were identified in their free and bound forms and were found to be mainly associated with the bran and the husk. On a whole grain basis, ferulic and p-coumaric acids accounted for 72% and 20% of total phenolic acids, respectively. The contents of the chemopreventive flavonoid tricin in the husk, bran, brown rice and white rice were 384.00, 39.71, 7.36 and 0.50 mg/kg, respectively. Eight vitamin E isomers, γ-oryzanol and phytic acid were also identified, and their distribution in the rice grain was recorded in the following decreasing order: bran, brown rice, white rice and husk. Overall, these results showed that the bran and husk of rice were rich sources of antioxidant compounds, revealing the potential multipurpose use of the rice grain parts.