During the extraction process, the solvent penetrates into the rice bran granules and combines with the oil, which diffuses from the rice bran granules into the solvent [ 7 ]. The oscillating extraction method can promote the diffusion of oil from the surface of the raw material into the solvent as quickly as possible to reach a uniform state.
How much oil can be extracted from rice bran?
An increase in oil yield was observed as the temperature and time rose. They obtained a complete decomposition of the lipase enzyme and a maximum RBO yield of 249 mg/g of dry rice bran (94% of the total oil from rice bran), which is comparable with the quantity obtained by means of hexane extraction.
How is rice bran oil refined?
After the extraction, the crude rice bran oil is often refined in order to improve its quality and commercial value. The fundamental steps of the refining process include dewaxing, degumming, neutralization of the free fatty acids, bleaching, and steam deodorization.
How is RBO extracted from rice bran?
The Japanese were the first to extract RBO from rice bran using the hydraulic press technique, which is still used nowadays, but recently, the preferred industrial technique for commercial uses is extraction using non-polar solvents, such as hexane [ 6 ].