Produção de sucedâneos de gordura de leite humano a partir de tripalmitina e de óleo de grainha de uva catalisada por lipases imobilizadas

Abstract

The aim of this study was the production of human milk fat substitutes (HMFS) by acidolysis of tripalmitin with free fatty acids (FFA) from grapeseed oil, in solvent-free media, catalyzed by sn-1,3 selective lipases. The commercial immobilized lipase from Rhizomucour miehei, Lipozyme RM IM and the recombinante Ryzopus oryzae lipase (rROL) immobilized on two different supports (Lewatit® VPOC 1600 and Sepabeads) were tested as biocatalysts. After 24h acidolysis at 60ºC and using a molar ratio (MR) tripalmitin/FFA of 2:1, molar incorporations of 20.5%, 19.8% and 14.4% of FFA in tripalmitin were achieved with immobilized rROL in Lewatit, in Sepabeads or with Lipozyme RMIM, respectively. rROL in Lewatit was selected for subsequent studies, due to its higher mechanical resistance to magnetic stirring. The activity of rROL immobilized on Lewatit increased with its initial water activity (aw). The highest molar incorporation of 20.5%, was observed at an aw of 0.95. Modeling and optimization of reaction conditions (temperature and MR) of acidolysis were performed by response surface methodology (RSM). The highest molar incorporation were obtained at lower temperatures and molar ratios (T=58ºC; MR=2:1). The rROL showed to be a feasible biocatalyst to produce HMFS