18E-23

H. A. AKSOY¹, R. Dagli², S. Yucel³, and G. Ustun¹. (1) Chemical Engineering, Istanbul Technical Univ., Maslak, Istanbul, 34469, Turkey, (2) Advanced Technologies in Engineering, Molecular Biology, Genetic and Biotechnology, Istanbul Technical Univ., Maslak, Istanbul, 34469, Turkey, (3) Chemical Engineering Dept., Istanbul Technical Univ., Maslak, Istanbul, 34469, Turkey

Structured Lipids (SL) are triacylglycerols (TAG) that contain Short-Chain Fatty Acids (SCFA) and/or Medium-Chain Fatty Acids (MCFA) plus Long-Chain Fatty Acids (LCFA) with the specific location of each group on the same glycerol molecule. SCFA or MCFA at the 1- and 3- positions are rapidly oxidized in the liver as readily available energy and are not deposited in adipose tissues. Recently, researchers have focused on the enzymatic acidolysis of TAG to produce SL in solvents because of the mild reaction conditions and reduction of the side products. Our objective was to prepare a reduced-calorie SL from tripalmitin and lauric acid using 1-3 specific lipase. Enzyme load and substrate mole ratio effects on the reaction and fatty acid compositions of TAG were investigated. Acidolysis of tripalmitin was conducted using 0.7 g of substrates, Lipozyme IM, 1-3 specific lipase and 5 mL hexane in an orbital shaker at 200 rpm and 50^o C for 6 h. Reaction products composed of TAG and free fatty acids (FFA) were heated at 90 ^o C for 15 min to inactivate the enzyme. Then the products were titrated against a 0.02 M NaOH to separate the TAG from FFA. Fatty acid compositions of TAG were determined by gas chromatography. Our result showed that the highest lauric acid incorporation (34%) into tripalmitin was occurred when the reaction was conducted at 50^o C for 6h using 9% enzyme based on substrates weight at 1:3 tripalmitin: lauric acid mole ratio. The effect of substrates mole ratio was investigated using 9% enzyme and changing the tripalmitin/ lauric acid mole ratio 1.2 to 1:6 and it was observed that the lauric acid incorporation into tripalmitin was increased to 51 % at tripalmitin/ lauric acid mole ratio of 1:5. The acylglycerols pruduced from tripalmitin containing high content of lauric acid (51%) could be used to prepare reduced-calorie lipids.

Session 18E, Nutraceutical & Functional Foods: General I
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana