Selective extraction of lipid classes from Solieria chordalis and Sargassum muticum using supercritical carbon dioxide and conventional solid-liquid methods

摘要

Lipid extraction yields and lipid class distribution from two seaweeds Solieria chordalis (Rhodophyceae) and Sargassum muticum (Phaeophyceae) were investigated using different extraction methods. Supercritical carbon dioxide extraction with or without co-solvent and chloroform/methanol extractions were applied to S. chordalis and S. muticum. Total lipid contents ranged between 0.13 and 2.96% dry weight (dw) and between 0.8 and 3.15% dw for S. chordalis and S. muticum, respectively. The best yields were obtained from chloroform/methanol mixture. A promising 1.21% dw yield was obtained from supercritical CO2 with 2% ethanol for S. chordalis. The proportion of the lipid classes drastically changed according to the method. By using the chloroform/methanol Bligh and Dyer mixture, the main fractions extracted from S. chordalis were neutral lipids (37%) and glycolipids (38%) whereas glycolipids (60%) were mainly isolated using pure supercritical CO2. An addition of ethanol (2%) as co-solvent enhanced the neutral lipid fraction up to 56%. The glycolipid fraction reached 82.2% of total lipids when S. muticum was treated by supercritical CO2, and 61.2 to 70.8% for chloroform/methanol procedures. More broadly, polar lipid ratio (glycolipids and phospholipids) was important in the brown seaweed with 86 to 95% of total lipid content. These results highlighted the relationships between the extraction process and the lipid class distribution.