Rice bran is a low value by-product of rice milling , which contains 15-23% oil . Rice bran oil (RBO) is one of high nutritive oils due to the presence of essential fatty acids and the presence of biologically active antioxidants like γ-oryzanol. The use of RBO as edible oil has been hindered by difficulties in processing and refining due to the presence of high free fatty acids (FFA) and gums . High FFA content in RBO is inevitable due to the hydrolytic action by the indigenous lipase. Upon milling the bounded lipids are further exposed to the lipase, resulting in spoilage of the oil . A key reactant during hydrolysis is the presence of moisture (water). Total removal of moisture before milling is unlikely, since a good milling process requires the rice paddy to have a moisture content of 14% as per advised by the International Rice Research Institute (IRRI). This is to avoid breaking the milled rice grain and to maintain high quality grains. In the past decades many researches have been carried out on lipase deactivation and bran stabilization. Nevertheless its practical application is difficult to implement due to the dispersed nature of rice milling and the difficulty to continuously gather freshly milled rice bran from various mills . With considerable amounts of extractable oil (comparable to soybean) and a cheap resource, rice bran is a potential feedstock in the production of biodiesel.
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