| Summary: | Doutoramento em Engenharia Alimentar - Instituto Superior de Agronomia The aim of this study was the production of structured lipids (SL) containing medium-chain fatty acids (M) in positions sn-1,3 and long-chain fatty acids (L) in the sn-2 position(MLM type). These SL were obtained by acidolysis of virgin olive oil with caprylic or capric acid in n-hexane or in solvent-free media. Acidolysis reactions were catalysed by commercial lipase preparations from Thermomyces lanuginosa, Rhizomucor miehei and Candida antarctica (“Lipozyme TL IM”, “Lipozyme RM IM” and “Novozym 435”, respectively). The higest incorporation values of M were obtained in solvent-free media (19.9-30.4 mol%) than in the presence of n-hexane (13.6- 21.9 mol%). “Lipozyme RM IM” presented the best operational stability in consecutive batches (half-life time, t1/2, of 299h). The sn-1,3 selective recombinant Rhizopus oryzae lipase (r-ROL), produced by the methylotrophic yeast Pichia pastoris, was tested as alternative for the commercial lipases. The r-ROL was immobilized in Eupergit® C, in modified sepiolite or in Lewatit® VP OC 1600. Lewatit® VP OC 1600 showed to be the best support for r-ROL immobilization, since higher operational stability was observed when this lipase preparation was reused in consecutive batches with rehydration between batches (t1/2 =234h). r-ROL is a feasible biocatalyst for the production of MLM by acidolysis.
|
|---|