Fatty acid composition was determined after methylation (IUPAC, 1990) by a Shimadzu gas chromatograph (ModelGC‐2010, Shimadzu Corporation, Kyoto, Japan) using a Optima® FAP column (60 m × 0.25 mm I.D., 0.25 μm) (Macherey‐Nagel, Düren, Germany). The temperatures of the injector port and detector were held at 260°C and 280°C, respectively. The injection volume was 1 μl. The carrier gas was helium at a pressure of 150 kPa. The split used was 1:100. The temperature of the column was held at 140°C for 2 min, raised to 170°C at 10°C/min and 215°C at 10°C/min, held at 215°C for 5 min, raised again to 230°C at 5°C/min and held at 230°C for 5 min, and finally raised to 240°C at 10°C/min and held at 240°C for 35 min. The identification of fatty acids was carried out by comparing their retention times with that of a standard mixture of fatty acids (Supelco 37 Component FAME Mixture, Cat. No. 18919‐1 Amp, St. Louis, MO, USA). The final concentration of fatty acids was reported as mg/g fat. All analyses were performed in triplicate.