ORIGINAL PAPER Optimization of Edible Oil Extraction from Ofada Rice Bran Using Response Surface Methodology Rahman Akinoso & James A. Adeyanju Received: 13 May 2010 / Accepted: 19 October 2010 / Published online: 30 October 2010 # Springer Science+Business Media, LLC 2010 Abstract Effects of roasting temperature and duration on yield and quality (free fatty acid, peroxide value, color) of oil extracted from ofada rice bran was studied using response surface methodology. Roasting temperature and duration were 160, 170, 180, 190, and 200 °C and 5, 10, 15, 25, and 35 min respectively. Data were analyzed by ANOVA and regression analysis. The oil yield ranged between 11.31% and 14.4%, free fatty acid (7.10–12.75%), peroxide values (8.25–13.25 mEq/kg) and color (1.51–1.58 abs). The treatments have significant effects on oil yield, free fatty acid, peroxide values, and color at p <0.05. Coefficient of determination R 2 of oil yield, free fatty acid, color, and peroxide value models were 0.79, 0.91, 0.99, and 0.99 respectively. Optimum temperature and duration of roasting were 190 °C and 10.75 min, respectively. This combination gave 14.45% oil yield, 5.80% free fatty acid, 8.25 mEq/kg peroxide values and 1.51 abs oil color. Desirability of optimization was 0.99. Keywords Ofada rice bran . Roasting temperature . Roasting duration . Response surface methodology . Oil yield . Oil quality . Optimization Introduction Oilseeds are important component of modern agriculture. They are source of nutritious human and animal food. The major world edible oilseeds are soybeans, sunflowers, rapeseed, cotton, and peanuts. Oil content of vegetable oil-bearing materials varies between 3% and 70% of the total weight of the seed, nut, kernel, or fruit (Bachman 2004). The rate of vegetable oil consumption is increasing compared with animal fat due to its health implication (Akinoso et al. 2006). Oil is recovered from plant either by solvent method, mechanical expression, or combination of the two methods. Direct solvent extraction is suitable for oil seeds containing less than 20% oil, while mechanical expression is appropriate for oil seeds greater than 20% but less than 50%, and pre-pressing solvent extraction for high-oil content seeds exceeding 50% (Veloso et al. 2005). Rice (Oryza sativa) is one of the most widely used crops in the world for human consumption. Rice bran, a by- product of rice milling industry, is a soft and fluffy powdery material. It is composed of several botanical entities such as pericarps seed coat, nucellus, aleurone layer, germ, and part of subaleurone layer of the starchy endosperm (Most et al. 2005). The bran is a rich source of valuable nutrients. It's chemical composition, nutrition profile, and functional characteristics of rice bran encouraged its wide applications such as composite flour, animal feed, and for oil extraction (Renuka and Arumughan 2007). Interest in rice bran oil is growing due its health and nutritional quality and wide application as industrial oil. Rice bran oil in its natural state contains several constitu- ents which would potentially provide benefits to health (Raghuram and Rukmini 1995). The fatty acid profile of rice bran oil is palmitic acid (16.74%), stearic acid (1.9%), oleic acid (42.79%), linoleic acid (34.65%), and linolenic R. Akinoso (*) Department of Food Technology, Faculty of Technology, University of Ibadan, Ibadan, Nigeria e-mail: akinoso2002@yahoo.com J. A. Adeyanju Department of Food Science and Engineering, Faculty of Engineering and Technology, Ladoke Akintola University of Technology, Ogbomoso, Nigeria Food Bioprocess Technol (2012) 5:1372–1378 DOI 10.1007/s11947-010-0456-8