FAMEs analysis
The esters were separated on a VS-23 capillary column (30 m × 0.25 mm). The oven temperature was kept at 50 °C for 5 min, followed by a 3 °C/min ramp to 240 °C, and then held for an additional 5 min period. Helium was used as the carrier gas at a flow rate of 1 mL/min. The injector and detector temperatures were maintained at 260 °C. FAMEs were identified by comparison of their retention times with those of pure reference standards (FAME mix: 18919-1, Supelco, Bellefonte, PA, U.S.A.).