Effect of Extraction Method on The Level of Important Antioxidants in Rice Bran Oil

Abstract

Rice bran oil is one of the healthiest edible oils due to higher levels of antioxidants, which have beneficial health effects. Extraction procedures significantly affect the concentration of the antioxidants and yield of lipids from bran. Compared to conventional solvent extraction, environmentally friendly supercritical fluid extraction (SFE) procedures are gaining increased acceptance for extraction of nutraceutical compounds from biological materials. Rice husk ash obtained after burning of husk in the energy generation system exhibit absorbent properties for lipid components such as free fatty acids, phospholipids, lutein etc. In the present study three different extraction methods (1) Soxhlet extraction with petroleum ether (2) SFE (3) SFE coupled with adsorption on rice hull ash; were investigated for their effect on level of antioxidants in the rice bran oil and oil yield. In soxhlet extraction time of extraction was varied from 6 to 10 hrs. During SFE extraction pressure (6000 and 8000 psi) and flow rate (45 and 65 g/min) of carbon dioxide were varied where as temperature was kept constant at 40 oC. Antioxidants level was higher with SFE extractions, where as oil yield was higher with soxhlet extraction. Pressure increase improved concentrations of antioxidants in SFE extractions where as flow was not having significant influence on it. Oil yield increased with both pressure and flow. Hull ash was having mixed effect on antioxidant concentrations. Further experiments are in progress at other extraction conditions.