For both extractions, the amounts of FAME after methylation of
the crude lipids were found to be roughly between 0.23 and 0.44 of
the masses of extracted crude lipids (Table 1 under ‘FAME yield/
experimental lipid yield’). Even though this result agreed with
the analysis reported by Cheung (1999), the majority of previous
work on microalgal lipid extraction did not report on the purity
of the extracted lipids. Despite the low affinity of SCCO2 for polar
compounds, the high concentration of polar lipids known to make
up the cell membrane (up to 90% of lipids) made concurrent leaching
during supercritical extraction of neutral lipids inevitable. As
such, polar lipids that were unsuccessfully esterified with the
applied methylation techniques (complex phospholipids and