Concentration of n-3 polyunsaturated fatty acids in cholesterol-reduced cod-liver oil by lipases

This study was conducted to elucidate the effects of different lipases originated from Candida rugosa (CR), porcine pancreas (PP) and Aspergillus niger (AN) on the degree of hydrolysis (DH) in cholesterol-reduced cod-liver oil (87.5%) and evaluate the changes in n-3 polyunsaturated fatty acid concentrations in the oil hydrolysed by the lipases. The lipase-catalysed hydrolysis of cholesterol-reduced cod-liver oil was performed at 37°C for 8h. Among all the lipase samples studied, DH in the oil after lipase-catalysed hydrolysis followed the decreasing order: CR lipase (70.01%) > PP lipase (26.18%) > AN lipase (18.57%). Triacylglycerol levels in the oil hydrolysed by all the lipases studied decreased, while mono- and diacylglycerol levels increased during lipase-catalysed hydrolysis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in cholesterol-reduced cod-liver oil hydrolysed by the CR lipase were remarkably higher than those by the PP or AN lipase. Thus, it is suggested in this study that the CR lipase appears to be most suitable for producing and n-3 polyunsaturated fatty acids including EPA and DHA concentrates from cholesterol-reduced cod-liver oil.