Effect of processing methods on the nutraceutical and antioxidant properties of red rice (Oryza nivara)

The effect of roasting, microwave cooking and pressure cooking/autoclaving on the nutraceutical and antioxidant properties of red rice (Oryza nivara) was investigated. The nutraceutical properties were determined by evaluating the total phenolic, flavonoid and phytic acid contents while the antioxidant properties were studied by the DPPH free radical scavenging activity and the iron reducing power assay. The results showed that the total phenolic and flavonoid of processed red rice increased, while phytic acid content was decreased when compared to native sample. The DPPH radical scavenging activity and the iron reducing power of roasted red rice extract were the highest compared to the other processed red rice. A significant increase in TPC, FRAP, reducing power and DPPH content was found in all the selected cereals while decrease in TFC was observed after microwave & roasting. The roasted flour exhibits higher AOA then microwave treated flour. The results indicate that processing has significant effects on the nutraceutical and antioxidant properties of selected cereals.