2.2. Lipid extraction
Lipids were extracted according to the method of Bligh and
Dyer (1959). Approximately 5 g of well-ground samples was extracted
with 50.0 mL of chloroform–methanol (2:1, v/v) containing
10 mg/L of butylated hydroxytoluene and 0.1 mg/mL of nanodecanoic
acid (C19:0, Sigma) as an internal standard. Then, the samples
were stored in a fume hood overnight. Each sample was filtered
and transferred into a separate funnel and added with 15 mL of
0.9% sodium chloride. The samples were shaken well to allow the
phases to separate; the lower phase was then evaporated and
transferred into a 10-mL volumetric flask.