The optimization of oil extraction by surfactant-assisted aqueous extraction process of rice bran (Oryza sativa L.) using Box-Behnken design

Surfactant-assisted aqueous extraction process (SAAEP) is used as an environmentally friendly alternative method for oil extraction. Rice (Oryza sativa L.) is one of the most widely produced and consumed foods, and it produces bran as a by-product. Therefore, this study aims to determine the optimum conditions for SAAEP from rice bran. The response surface methodology (RSM) technique was used to determine the optimum conditions. Furthermore, the Box-Behnken design (BBD) was selected as the study design with three factors and three levels. The independent variables used were surfactant and oil ratio (SOR) (3, 3.5, and 4), ultrasonication amplitude (60, 70, and 80), and ultrasonication contact time (15, 20, and 25 mins. Meanwhile, the dependent variable used was oil content. The extraction was carried out based on SAEEP. Also, the rice bran used was the IR 32 SR variety which passed the stabilization stage with a moisture content of 4.25, extracted oil of 20.64, and 2.04 meqO2/kg FFA levels. The optimal point was predicted to produce an extracted oil of 19.326. Furthermore, the prediction results were evaluated by experimental extraction at the optimal level. The results showed an extracted oil of 18.52±0.04, which is a difference of about 0.81 from the predicted values. It was concluded that the rice bran oil content can be successfully optimized using the RSM technique. Therefore, the optimum conditions for extracting rice bran oil are within the specified range of factors.