Extraction of rice bran oil using aqueous media

Abstract

Aqueous extraction of oil from rice bran was studied on a laboratory scale and the resulting product was examined. The following process parameters influencing oil extraction were individually investigated: pH of aqueous media, extraction temperature, extraction time, agitation speed and rice bran-to-water ratio. Extraction temperature and pH were found to be the main factors influencing oil extraction. The highest oil yield was obtained at pH 12.0, extraction temperature 50 °C, extraction time 30 min, agitation speed 1000 rpm, and rice bran-to-water ratio 1.5-to-10. The quality of aqueous-extracted oil in terms of free fatty acid, iodine value and saponification value was similar to a commercial sample of rice bran oil and hexane-extracted oil, but the peroxide value was higher. Furthermore, the colour of aqueous-extracted oil was paler than solvent-extracted oil. © 2000 Society of Chemical Industry