Extraction of rice bran oil using aqueous media

Aqueous extraction of oh 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 degrees C, extraction time 30 min, agitation speed 1000 rpm, and rice bran-to-water ratio 1.5-10-10. 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. (C) 2000 Society of Chemical Industry.