ปท 14 ฉบบท 1 มกรคม  มถนยน 2560 วรสรกษตรพรวรณ 124 Volume 14 Number 1 JANUARY– JUNE 2017 Research Article Concentration of Polyunsaturated Fatty Acid of Rice Bran Oil by Urea Complexation–A Response Surface Approach Pornpisanu Thammapat 1* and Sirithon Siriamornpun 2 1 Food Technology Program, Faculty of Agricultural Technology, Rajabhat Mahasarakham University, Mahasarakham 44000, Thailand. 2 Research Unit of Process and Product Development of Functional Foods, Department of Food Technology and Nutrition, Faculty of Technology, Mahasarakham University, Mahasarakham 44150, Thailand. The processes for the concentration of fatty acids in the production of polyunsaturated fatty acids (PUFA) have become very important because of the beneficial properties of these substances to human health and in functional foods. Optimization of the concentrating conditions of Polyunsaturated fatty acid (PUFA) extracted from rice bran oil was studied to obtain maximum concentration. The crude rice bran oil was extracted from the KDML105 rice bran variety, and the extracted oil was used as fresh crude oil. The PUFA was concentrated by the urea complexation method. A hexagonal rotatable design was applied to examine the effects of crystallization temperature and urea-to-fatty acid ratio on the total content of PUFA (Y). We investigated the changes of different crystallization temperatures (-10, 0 and 10 o C) and urea-to-fatty acid ratios (2:1, 3:1 and 4:1, w/w) on the total PUFA content. The second order polynomial regression model for response was employed to generate the response surfaces. Under the optimum conditions of -7.2°C and a urea-to-fatty acid ratio of 2.91 (w/w), the total concentration of PUFA could be increased by up to 77.48% was obtained. Keywords : Polyunsaturated Fatty Acids, Rice Bran Oil Concentrate and Urea Inclusion *Corresponding author: E-mail: Thammapat.p@gmail.com Abstract