Lipase-catalyzed acidolysis of algal oils with capric acid: Optimization of reaction conditions using response surface methodolgy

Abstract

Lipase-assisted acidolysis of algal oils, arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and a single cell oil rich in both docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA, n-6) known as OMEGA-GOLD, with a medium-chain fatty acid (capric acid) was studied. Response surface methodology was used to obtain a maximum incorporation of CA into algal oils. The process variables studied were the amount of enzyme (2-6 %), reaction temperature (35-55C) and incubation time (12-36 h). The amount of water added and mole ratio of substrate (algal oil to CA) were kept at 2% and 1:3, respectively. All experiments were conducted according to a face-centered cube design. Under optimum conditions (12.3% of enzyme; 45C; 29.4 h), the incorporation of CA was 20.0% into ARASCO, 22.6% into DHASCO (4.2% enzyme; 43.3C; 27.1 h) and 20.7% into the OMEGA-GOLD oil (2.5% enzyme, 46.6C; 25.2 h).