| The total fatty acid composition of DHA single cell oil was determined, and 2-MAG was obtained by ethanolysis of DHA single cell oil with Lipozyme 435. The positional distribution of fatty acid in DHA single cell oil was analyzed by gas chromatography combined with thin layer chromatography. Additionally, the triglyceride composition (TAG) of DHA single cell oil was separated and identified by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in electrospray ionization mode (UPLC-Q-TOF-ESI/MS/MS). The results showed that the DHA content (51.37%) in DHA single cell oil was the highest, followed by palmitic acid (31.13%) and DPA (10.78%). The contents of DHA and DPA in the sn-2 position were 72.65% and 18.21% respectively, and the palmitic acid content in the sn-1,3 position was 43.61%. DHA and DPA were evenly distributed in the sn-2 position and sn-1,3 position, while palmitic acid was typically located at sn-1,3 position. The most abundant TAG species in DHA single cell oil were (22∶?6-22∶?5-16∶?0),(22∶?5-16∶?0-16∶?0), (22∶?6-22∶?6-22∶?6), (22∶?6-22∶?6-22∶?5) and (16∶?0-16∶?0-16∶?0) with contents of 12.76%, 8.93%, 8.78%, 6.62% and 6.61% respectively, and they accounted for 43.7% of total glyceride. |
