Influence of extraction conditions on the recovery lipids extracted from the dry biomass of duckweed Lemna minor

Abstract

Previous studies on the composition of lipid content of higher aquatic plants can be found in the literature. The present work aims to study the effect of various solvent extraction systems on the recovery of lipids extracted from the dry biomass of Lemna minor, using the same polar solvent (ethanol) and variating the non-polar solvent as follow: methanol-ethanol, chloroform-ethanol, hexane-ethanol, diethyl ether-ethanol, petroleum ether-ethanol at different volume ratio. The goal is to select a Sohxlet extraction method that shortens the extraction duration and increases the lipid recovery using various solvents. To intensify the extraction process, homogenization was used as a cell disruption method. It is shown that the yield of total lipids is increased by using homogenization from 4.6% to 6.0%. When studying the influence of the solvent system, the highest yield of total lipids was obtained by using hexane-ethanol with a volume ration of 1:1 (8.0% total lipids by dry mass). The yield of lipids recovered from dry biomass of Lemna minor increases by increasing the extraction time. The optimum extraction time was found to be no more than 300 minutes. The composition of the lipid fraction is mainly represented by sterols, fatty acids and triglycerides.