| Summary: | 82 pages [EN] Long-chain n-3 polyunsaturated fatty acids (PUFA) have attracted an increasing attention due to their beneficial role on human health and nutrition. Structured triacylglycerols (TAGs) are molecules that have modified their composition and/or spatial distribution of fatty acids in the glycerol structure through chemical and/or enzymatic methods, thus obtaining an enhancement of their functional and nutritional properties. In this sense, enzymatic transesterification provides several advantages such as the employment of low temperatures and greater catalyst selectivity. In recent years, supercritical fluids technology has shown to provide an advantageous possibility in the enzymatic catalyzation process due to its versatility and safety. The objective of the present study was to optimize the process variables of enzymatic acidolysis of PUFA-enriched canola (Brassica napus L.) oil to obtain structured TAGs with a low n-6/n-3 fatty acids ratio. In order to achieve this objective, unspecific lipase B from immobilized Candida Antarctica was employed under supercritical-CO2 conditions. Salmon oil obtained from industrial by-products was utilized to obtain the starting PUFA source. As a first step, oils from canola and salmon were analysed by physico-chemical quality parameters (lipid hydrolysis degree and content on primary and secondary lipid oxidation compounds) and by gas-liquid chromatography to obtain their fatty acids profiles. A PUFA concentrate was obtained from salmon oil by basic hydrolysis and further urea complexation. Then, the process variables of enzymatic acidolysis were optimized by means of a composite-central design of 25-1 + star, with five factors and 30 experimental runs, based on the response-surface methodology (RSM). Optimal conditions that minimized the relationship AG n6/n-3 to a 1.16 score for the purified TAGs corresponded to a LCPUFA/canola ratio of 70.6%, temperature of 57.0 ° C, pressure of 178.0 bar, time of 19.6 h and enzyme concentration of 8.0%. [ES] Los ácidos ...
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