Today it is proven that some fats and oils have functional properties in human body and in addition to having nutritional value, they can have positive effects on human health. These compounds are known as functional lipids, nutrient lipids, medical lipids and pharmaceutical lipids. Some of these functional lipids are conjugated linoleic fatty acids (CLA), conjugated linolnic (CLN),gama linolenic and… . The aim of this study was to build a non-natural existing structured lipid (SL) containing both CLA and CLN, using enzymatic interesterification. Initially, the oil with high content of CLN was extracted from pomegranate seed and enzymatically interesterified with CLA oil. Several factors such as CLA percentage, reaction temperature and time were evaluated and finally the reaction was optimized by response surface methodology (RSM).To evaluate model and select optimized conditions, two responses of CLA/CLN ratio and free fatty acid percentage were measured. By considering the equal CLA/CLN ratio, lower FFA and desirable color in the product, optimizated condition for the reaction was obtained: 24h time,temperature 56?c and CLA content of 43%.TAG profile of oils showed that pomegranate seed oil and CLA oil had two dominant TAGs of LnLnLn (58.5%) and LcLcLc (54.3%), respectively,while SL oil had two new TAGs of LnLnLc (27.3%) and LcLcLn (27.9%). Physicochemical properties of SL oil were also determined. Iodine number of SL was measured (172.1) which was less than pomegranate seed oil but more than that of CLA oil. oxidative stability index of SL (0.36) was also less than two other oils. The comparative effect of CLA, pomegranate seed and SL oils was then evaluated on lipid indices of rats during a 45-day period. Final blood HDL content of CLA-fed rats was increased. Total cholesterol of pomegranate seed oil-fed rats was significantly decreased in comparison to soybean oil-fed (control) group. TAG content in liver showed a decrease for SL(13.28) and pomegranate seed oil (18/51mg/dl).The results showed that enzymatic interesterification could be used to synthesize a functional SL, containing CLA and CLN. As the results showed this SL is able to reduce lipid content in liver and can be introduced as a agent to prevent fatty liver. Keywords: Pomegranate seed oil, CLA oil, Structured Lipid, Functional
