1,3-Selective hydrolysis of blackcurrant seed oil for the concentration of alpha- and gamma-linolenic acids

Blackcurrant seed oil contains alpha-linolenic acid (a-Ln) and gamma-linolenic acid (g-Ln), essential fatty acids of different therapeutic effects. Lipid classes of various a-Ln/g-Ln ratios were previously produced by partial hydrolysis catalyzed by 1,3-specific lipases Lipozyme RM IM and Lipozyme TL IM, conducted in supercritical CO2 (scCO2) in a continuous packed-bed reactor. In this work, free fatty acids (FFA) were separated from glycerides using preparative chromatography on silica gel with scCO2 as mobile phase in order to obtain two clean, natural products of different a-Ln/g-Ln ratios, and fatty acid profiles in hydrolysates obtained under different conditions were reviewed. Using Lipozyme RM IM and maintaining the FFA mass fraction in hydrolysate below that of partial glycerides, the a-Ln/g-Ln ratio increased from 1.3 in oil to 10.7 in FFA. Lipozyme RM IM-mediated hy-drolysis showed steric hindrance of g-Ln, while silica support of Lipozyme TL IM promoted acyl migration.