The extraction process of rice bran oil is a way of obtaining the oil from the hard outer layer of rice, which is rich in nutrients and antioxidants. There are different methods for extracting rice bran oil, but the most common one is solvent extraction using hexane. This method involves the following steps:
1. Rice bran raw material preparation: The rice bran is obtained from the milling process of rice and then stabilized to prevent rancidity and improve the oil yield.
2. Extraction: The stabilized rice bran is soaked in hexane, a chemical solvent, to dissolve the oil. The oil-hexane mixture is then separated from the solid residue by filtration or centrifugation.
3. Rice bran oil refining: The crude oil is further purified by degumming, neutralization, bleaching, and deodorization to remove impurities and improve the quality and stability of the oil.
Some alternative methods for extracting rice bran oil are expeller pressing, which uses mechanical pressure to squeeze out the oil, and supercritical fluid extraction, which uses high-pressure carbon dioxide to extract the oil. These methods are considered more environmentally friendly than solvent extraction, but they may have lower oil yields or higher costs.