| Abstract: | A very simple and versatile GC method has been developed that can be utilized for quick analysis, in many samples, of the FA compositions at the sn-2- and sn-1,3-positions of TAG. By using the lipase-catalyzed, sn-1,3-regioselective esterexchange reaction of TAG with ethyl acetate, followed by direct injection of the crude reaction mixture into the GC apparatus without any pretreatment, the FA located at the sn-2-position could accurately be analyzed as a TAG derivative in which the sn-1,3-positions were substituted by an acetate residue. Furthermore, the FA located at the sn-1,3-positions could simultaneously be analyzed as the corresponding ethyl ester derivatives using this method. The reliability of the analytical method was compared with conventional methods by analyzing the TAG consisting of caprylic acid (C) at the sn-2-position and oleic acid (O) at the sn-1,3-positions, giving comparable analytical results. The present method was applied to the analysis of the structured lipids CCD and CCE, consisting of TAG as a major component in which C and the highly unsaturated FA, DHA (D) or EPA (E), were specifically bound at the sn-2- and the sn-1,3-positions, respectively. |
