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.
Which solvent is used in rice bran oil extraction?
The solvents applied in the extraction processes are generally organic compounds derived from non-renewable sources . Hexane is the most common solvent used in rice bran oil extraction . This solvent is cheap and efficient, but it is a petroleum-based solvent, volatile, flammable, and dangerous for humans and for the environment .
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 ].
How to improve the extraction ratio of rice bran oil?
Author to whom correspondence should be addressed. In order to improve the extraction ratio of rice bran oil, a single-factor experiment and response surface methodology with a central composite design were used to determine a new mixed solvent and the optimal extraction conditions of the mixed solvent.