The process of making rice bran oil involves several steps, such as:
- Rice bran raw material preparation: Rice bran is obtained from the milling of rice grains. It is cleaned, dried, and stored in a cool place to prevent rancidity and enzyme activity.
- Rice bran oil extraction: There are two main methods of extracting oil from rice bran: mechanical pressing and solvent extraction. Mechanical pressing involves squeezing the oil out of the rice bran using a screw press or a hydraulic press. Solvent extraction involves using a chemical solvent, usually hexane, to dissolve the oil from the rice bran. The solvent is then evaporated to recover the oil.
- Rice bran oil refining: The crude rice bran oil obtained from the extraction process contains impurities, such as free fatty acids, phospholipids, pigments, and wax. These impurities need to be removed to improve the quality and stability of the oil. The refining process includes degumming, neutralization, bleaching, deodorization, and dewaxing.