초록
<P>Stearidonic acid (SDA) from echium oil was enriched substantially by a two‐step lipase‐catalyzed esterification using Lipase OF from <I>Candida rugosa</I> and Lipozyme RM IM from <I>Rhizomucor miehei</I>. During the first step, SDA was enriched in the fatty acid fraction via <I>C. rugosa</I> lipase‐catalyzed esterification with lauryl alcohol. The optimum reaction conditions of water content, temperature, and enzyme loading were 0.25%, 30°C, and 2%, respectively, in terms of the content and yield of SDA. Under these conditions, SDA content was increased to 39.3 from 14.3% of the starting material. To further elevate SDA content, Lipozyme RM IM‐catalyzed esterification was then conducted using the SDA enriched fatty acid from the first step and a maximum SDA content of 54.1% was obtained. Using this two‐step lipase‐catalyzed esterification, SDA content increased fourfold from 14.3 to 54.1% with a 74.8% yield. γ‐Linolenic acid (GLA) was also enriched together with SDA.</P><P><B>Practical applications:</B> SDA, which is one of ω‐3 fatty acids, is considered as a source of health beneficial polyunsaturated fatty acids for vegetarians. SDA enrichment obtained in this study leads also to a high level of GLA. Therefore, this enrichment can be applied to produce a novel structured lipid containing a significant amount of SDA and GLA.</P>