摘要：Algal oil, rich in docosahexaenoic acid (DHA) and an environmentally sustainable source of ω‐3 fatty acids, is receiving increasing attention. In the present study, a novel approach combining ethanolysis with a 1,3‐specific immobilized lipase (Lipozyme ® TL IM) and molecular distillation was investigated to increase the DHA content of algal oil. Algal oil with a 45.94% DHA content was mixed with ethanol, pumped into a column filled with Lipozyme ® TL IM, and then circulated for 4 hr at room temperature. The ethanol was then recycled by vacuum distillation. At an evaporator temperature of 150°C, the residue was separated by molecular distillation into a heavy component enriched with DHA glycerides (in the form of triglyceride (TG), diglyceride (DG), and monoglyceride (MG)) and a light component enriched with palmitic acid (PA) and DHA ethyl ester (EE). As a result, 76.55% of the DHA from the algal oil was present in the heavy component, whose DHA content was 70.27%. DHA‐MG was collected in the heavy component mostly in the form of 1‐MG. Lipozyme ® TL IM appeared to specifically target PA rather than DHA at the sn‐1(3) position. The Lipozyme ® TL IM allowed 90.03% of the initial DHA yield to be retained after seven reaction cycles. Therefore, an eco‐friendly and simple method for increasing the DHA content in algal oil has been developed.
