Effect of refining process on oryzanol content of rice bran oil

Rice Bran Oil (RBO) is an oil derived from the outer layer of rice grains, which has many health benefits. However, it’s has been recognized to be difficult to refine due to the high content of free fatty acid, unsaponifiable matters, and color. Therefore, the present study was conducted to evaluate the quality and oryzanol content during the crude RBO refining process. Crude RBO was obtained by the reflux method using n-hexane as a solvent, followed by the dewaxing process by cooling and filtering procedure. The degumming process was carried out by adding phosphoric acid 1.5%; 3% and 4.5% (v / v), respectively, and the deacidification process was performed by adding 4.5% (w / v) sodium hydroxide. The refined RBO quality was evaluated visually and the oryzanol content was determined by TLC-densitometry. The extraction process was yielded by 15.6 ± 0.01%. (w / w) of crude RBO. There was a loss of oil weight of 17.74%, 5.67%, and 10.27% after the process of dewaxing, degumming (phosphoric acid 1.5%, 3%, and 4.5%), and deacidification (NaOH 4.5%). TLC densitometry indicates the presence of compounds in crude RBO and RBO that have been degummed (phosphoric acid 1.5%, 3%, and 4.5%), but after deacidification (NaOH 4.5%), there was no oryzanol found.