Fatty acid composition and squalene analysis
First, oil samples were converted to fatty acid methyl esters (FAME) by dissolving oil samples (about 10 mg) in 1.4 ml hexane followed by adding 2 N methanolic KOH (200 μL) and shaking for 2 min with a Vortex mixer (Ichihara et al., 1996). After two layers were separated, the top layer was transferred to a vial, and then analyzed with a Shimadzu 2010 gas chromatograph (Shimadzu, Columbia, MD) with a flame ionization detector (FID). The column was a Phenomenex (Torrance, CA) ZBFAME capillary column (30 m × 0.25 mm ID × 0.20 μm film). The GC conditions were the same as reported by Winkler-Moser et al. (2023). Commercial FAME and squalene standards were used to identify peaks in the GC chromatograms. The average values of relative peak areas measured in duplicate are reported.