Concentration of stearidonic acid from ahiflower seed oil via lipase-catalyzed hydrolysis and ethanolysis

Abstract: Stearidonic acid (C18:4, cis-6,9,12,15), which is one of the important n-3 polyunsaturated fatty acids, has various biological activities in humans such as, the prevention of cardiovascular, inflammatory, and autoimmune diseases. Moreover, the degree of conversion of SDA to DHA is much higher than α-linolenic acid due to Δ6‐desaturase, limiting enzyme. In the present study, SDA was concentrated from from Ahiflower seed oil with 20% SDA content by two different lipase-catalyzed reactions, which are selective hydrolysis and ethanolysis. In the first step, SDA was concentrated in the glyceride fraction from Ahiflower seed oil via Candida rugosa lipase-catalyzed selective hydrolysis. After hydrolysis, the reaction mixture was composed of glycerides (triacylglycerol, diacylglyceride, and monoacylglycerol) and fatty acid. The SDA content of the glyceride fraction was approximately 40 %. In the second step, SDA was further concentrated with the reaction mixture from the first step by ethanolysis using Lipozyme RM IM (from Rhizomucor miehei) as a biocatalyst. Moreover, the aforementioned reaction mixture was employed directly without the additional step, which is to remove the fatty acid. Finally, the SDA content in the glyceride fraction was over 60% after the two enzyme reactions.