Enzymatic treatment of rice bran to improve processing

A modification of the process of oil extraction from rice bran is proposed, introducing one or two enzymatic reactions previous to solvent extraction. Although a total aqueous enzymatic extraction process did not result in reasonable oil extraction yields, an interesting alternative results from enzymatic reactions previous to solvent extraction or pressing. A thermal treatment of rice bran is first applied to deactivate lipase, but also to gelatinize starch previous to reaction with alpha-amylase. This is followed by a saccharifying step with glucoamylase to produce glucose (28 g/100 g of rice bran treated), while the residual paste, 66.7% of the original bran, may be subjected to a proteolytic process for protein extraction or directly treated with the solvent to obtain bran oil. Finally, under the defined extraction conditions using hexane, yields of oil are 5% higher when rice bran has been previously treated with alpha-amylase.