33G-19 |
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A. LOPEZ-HERNANDEZ, UNIDA - Instituto Tecnológico de Veracruz., Apdo. Postal 1420, Mexico., Veracruz, Ver., 91860, Mexico, H. S. Garcia, UNIDA, Instituto Tecnologico de Veracruz, M.A. de Quevedo # 2779, Col. Formando Hogar, Veracruz, Ver., 91897, Mexico, and C. G. Hill, Jr., Dept. of Chemical Engineering, Univ. of Wisconsin, Madison, 1415 Engineering Dr., 1004 Engineering Hall, Madison, WI 53706-1607. Recently, the beneficial metabolic effects of the different isomers present in conjugated linoleic acid (CLA) have been extensively studied. Unfortunately, the content of this type of isomers of the linoleic acid in natural foods is relatively low. The production of structured fats containing CLA is a very attractive way to improve the ingestion of such fatty acids. Lipase-catalyzed synthesis has proved to be a very effective way to incorporate a great variety of fatty acids into glycerides, via the so called acidolysis reaction. In this work, our objective was to produce fats enriched with different CLA contents by exchanging the original acyl groups present in a palm stearin (Aarhus Inc, Port Newark, NJ) with free CLA (90% purity, kindly gift of University of Wisconsin-Madison’s Food Research Institute). All Reactions were performed at performed at 60 and 70°C at mole ratios of 1:1 and 2:1 (CLA : Triacylgycerol), in batch reactors agitated at 300 rpm. Lipases from Thermomyces lanuginosus (TL IM), Rhizomucor miehei (L9) and Pseudomonas cepacia (PS) were tested for this purpose. The extent of reaction was followed by gas chromatography and the hydrolysis level was determined by HPLC. We observed that only two lipases, TL IM and L9, were capable of incorporate CLA in appreciable amounts into the palm stearin (PS). The maximum yield of CLA incorporation corresponded to c.a. 89 and 83% for 1:1 and 2:1 mole ratios, respectively. No significative difference was observed when temperature was raised from 60 to 70°C. CLA was mainly exchanged for palmitic acid, which relative presence was reduced 15 and 25% for each mole ratio tested. Analysis of glycerides showed that the level of hydrolysis for all the tested condition was practically negligible. The products obtained here can be further purified by molecular distillation and used to formulate different food products.
Session 33G, Nutraceuticals & Functional Foods: Lipid and probiotic functional foods
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