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.