Extraction of rice bran oil using aqueous media

Aqueous extraction of oh from rice bran was studied on a laboratory scale a nd the resulting product was examined. The following process parameters inf luencing 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 facto rs influencing oil extraction. The highest oil yield was obtained at pH 12. 0, extraction temperature 50 degrees C, extraction time 30 min, agitation s peed 1000 rpm, and rice bran-to-water ratio 1.5-10-10. The quality of aqueo us-extracted oil in terms of free fatty acid, iodine value and saponificati on value was similar to a commercial sample of rice bran oil and hexane-ext racted oil, but the peroxide value was higher. Furthermore, the colour of a queous-extracted oil was paler than solvent-extracted oil. (C) 2000 Society of Chemical Industry.