Conjugated diene value (CDV)
CDV was measured spectrophotometrically at 234 nm and read against HPLC grade hexane as blank. The oil samples were diluted to 1:600 with hexane. An extinction coefficient of 29000 mol l–1was utilized to quantify the concentration of conjugated diene hydrperoxides formed during oxidation (Saguy et al., 1996).