AMBIENT-TEMPERATURE EXTRACTION OF RICE BRAN OIL WITH HEXANE AND ISOPROPANOL

Hexane and isopropanol were compared as solvents for use in ambient-te mperature equilibrium extraction of rice bran oil (RBO). Isopropanol w as as effective as hexane in extracting RBO when 20 mL of solvent was used to extract 2 g of bran. Free fatty acid levels were 2-3% in both solvents and similar to that previously reported for hexane extraction of RBO hexane extraction by this method. Larger-scale extractions wit h 30 g of bran and 150 mL of solvent produced oil with a similar free fatty acid content and a phosphorus level of approximately 500 ppm. Th e oil extracted with isopropanol was significantly more stable to heat -induced oxidation than hexane-extracted oil. Antioxidants that are mo re easily extracted by isopropanol than hexane may be responsible for the increased stability.