Ilyasoglu, H.

The aim of this study was to evaluate the usage of rosehip seed powder (RSP) extract in flaxseed oil to retard lipid oxidation. The acetone extract of the RSP (500 mg kg-1; 1000 mg kg-1) was used. Synthetic antioxidant BHT (200 mg kg-1) was added into the flaxseed oil to evaluate the antioxidant potential of the RSP extract. The peroxide value (PV), TBARS value, and p-anisidine value (p-AV) of the flaxseed oil were analysed during 12 days of storage. The total oxidation (TOTOX) value was also calculated. The sample with the RSP (500 mg kg-1; 1000 mg kg-1) generally showed lower PV, p-AV, and TOTOX value than the control sample and sample with the BHT. These results indicated that the RSP may be used in edible oils to prevent lipid oxidation as a source of natural antioxidants.

Bakir, N.; Ilyasoglu, H.; Yucetepe, A.; Kasapoglu, K. N.; Demircan, E.; Ozcelik, B.

The aim of this study was to synthesize structured lipid from hazelnut oil with conjugated linoleic acid (CLA) by lipase-catalyzed esterification reaction. The incorporation of CLA into hazelnut oil was optimized by response surface methodology (RSM). Substrate molar ratio, time, and temperature were independent variables chosen for optimization of the reaction. Substrate molar ratio was the most significant variable on the incorporation of conjugated linoleic acid. Good quadratic model was achieved by multiple regression analysis and backward elimination. Optimal incorporation conditions were determined as follows: reaction temperature, 59 degrees C; time, 6 hours; substrate molar ratio, 4. Under these optimum conditions, a maximum incorporation ratio of CLA into hazelnut oil of 49.42% was achieved.

Ilyasoglu, H.

A structured lipid (SL) constituting omega fatty acids was synthesized by using linseed and grape seed oils as substrates via a lipase-catalyzed reaction. Lipozyme® TL IM was used as a biocatalyst. Good quadratic models predicting the incorporation of omega fatty acids were achieved via the Response surface methodology (RSM). The optimal conditions for targeted omega-6/omega-3 fatty acid ratio (2:1) were obtained at a substrate molar ratio 1.4, time 8.4 h, and enzyme amount 6.4%. The SL contained linoleic acid (43 g 100g-1), which was mainly located in the sn-2 position (40 g 100g-1). α-Linoleic acid, and α-linolenic acid at the sn-2 position were 22 g 100g-1, and 11 g 100g-1, respectively. The oxidative stability of the SL, and SL with antioxidants was also investigated. The produced SL may be proposed as a source of a balanced intake of omega fatty acids and an ingredient in functional food formulations.