Synthesis of pinolenic acid-enriched triacylglycerol from pine nut oil via a two-step consecutive enzyme reaction: Comparison of acyl donors

Pinolenic acid (PLA) is a plant-origin Δ5-unsaturated polymethylene-interrupted fatty acid that provides several beneficial health effects to the human body. A two-step lipase-catalyzed reaction was carried out to synthesize PLA-enriched triacylglycerol (TAG) with pine nut oil (PNO) in the present study. In the first step, PLA was efficiently enriched from an initial value of 15–43 mol% in ethyl ester of the reaction mixture after Lipozyme 435-catalyzed ethanolysis with PNO. In the second step, PLA-enriched TAG was efficiently synthesized with the fatty acid form via Lipozyme 435-catalyzed esterification at all temperatures when both ethyl ester form and fatty acid form were compared as acyl donors. The effect of vacuum on the synthesis of PLA-enriched TAG with glycerol and PLA-enriched fatty acid was studied. The optimum temperature and vacuum were 60°C, and 50 mmHg, respectively. A maximum TAG conversion of approximately 95% was achieved after 12 h under the optimum conditions.