Efficacy of some commercial lipases in hydrolysis of palm olein for the production of free fatty acids and diacylglycerol oil

Palm olein, which is an abundant cheap vegetable oil, can be used for production of value-added products such as free fatty acids (FFA) and diacylglycerol (DAG) oil. In this study, the efficacy of four commercial lipases (Lipase A, Lipase AY, Lipozyme RM IM and Lipozyme TL IM) and one phospholipase (Lecitase Ultra) in hydrolysis of palm olein was investigated. Lecitase Ultra and Lipozyme RM IM were the most selective enzymes towards hydrolysis of saturated fatty acids. Lipozyme TL IM was found to be selective towards unsaturated fatty acids. Lipase A and Lipase AY were almost non-selective. At optimum hydrolysis condition, FFA and DAG oil yields of 55.0%-94.5% and 5.5%-45.0% were obtained, respectively. The highest FFA or DAG oil yields were obtained using Lecitase Ultra (94.5%) and Lipase AY (45.0%), respectively. The DAG oils contained 39.0%-42.2% DAG and had higher slip melting point, solid fat content and iodine value, and lower content of saturated fatty acids than palm olein. Totally, Lecitase Ultra may be of importance due to its high FFA yield and saturated fatty acid selectivity. However, when a high yield of DAG oil is of interest, Lipase AY will be the best choice