Estimation of Docosahexaenoic Acid Glycerides in Schizochytrium sp. Oil by Open Column Chromatography and Reversed‐phase HPLC

Abstract

AbstractColumn chromatography and reversed‐phase HPLC using a Sepax BR‐C18 column were applied for the analysis of glycerides in the docosahexaenoic acid (DHA) oil by Schizochytrium sp. The oil was detected under UV light after isocratic elution with 20 % 2‐propanol/hexane (5:4, v/v) + 80 % acetonitrile. The correlation coefficients for the calibration of HPLC for DHA glycerides were in the range of 0.9958–0.9998. The accuracy was confirmed with recoveries of 93.47–102.25 %. DHA oil samples under different aeration rates were successfully analyzed and the content of the binding of DHA on the acylglycerol backbone was very low (1.81–4.21 %). However, the content of glycerides (tri‐, di‐, mono‐) separated by column chromatography was more than 87.22 %. The glycerides were largely composed of triacylglycerides (TAG) (82.29–89.54 %), where higher content of TAG correlated to higher contents of DHA and TAG of DHA (TriDHA). In addition, the optimal aeration rate of 250 m3/h was obtained for TAG, DHA, and TriDHA production by Schizochytrium sp. with the temperature 30 ± 0.5 °C, impeller speed 85 ± 5 rpm and pressure 0.04 Mpa.