Sequential Supercritical Fluid Extraction of Lipids. Application to the Obtention of the Fatty Acid Profile of Some Genetically Modified Varieties of Corn

Abstract

The sequential supercritical fluid extraction of neutral and polar lipids from corn is presented in this work. The effect of the different parameters on the extraction was studied. It was found that pressure and temperature were the parameters that most affected the extraction of neutral lipids using pure CO2. The best results were obtained at 300 bar and 60°C. Flow rate and dynamic extraction time had also some influence on the extraction yield. In this way, working at 3 ml/min for 150 min, the percentage of remaining lipids was lower than 1.0%. Afterwards, and in order to extract the polar lipids, the residual corn material was subjected to the supercritical fluid extraction using CO2 modified with methanol. The amount of lipids extracted increased when the percentage of methanol and the dynamic extraction time rose, achieving the best results when using 15% (v/v) methanol and 90 min of dynamic extraction. The developed method was successfully applied to obtain, by gas chromatography-mass spectrometry, the fatty acid profile of several genetically modified corn samples and their isogenic lines.