The effect of rice bran oil coating in the Portuguese "Carolino" rice

Abstract

This study aims to nutritionally enrich Portuguese “Carolino” white rice (Oryza sativa japonica) by incorporating rice bran oil (RBO) on grain surface. Three levels of RBO coating were used: 0% (control), 0.3% and 0.6% (w/w). Antioxidant capacity (DPPH and ABTS), vitamin E (,  and - tocopherols), and Total fat % were determined. Also, acid value (AV) and peroxide value (PV) were measured on day one and after 183 days of storage to assess samples stability. Samples with 0.6% RBO presented significantly (p<0.05) higher concentrations of -tocopherol (39.52±12.57 g/g) and were the only sample where -tocopherol was quantifiable (14.05±1.85 g/g). DPPH increased with the RBO addition, but no significant differences were found by ABTS analysis. PV and AV increased over time, with 0.6% RBO samples presenting the highest values (p<0.05). Adding 0.6% of RBO to Carolino rice increased the tocopherols concentrations and antioxidant capacity, adding value to white rice.