Fatty Acid Profiling of Longissimus Thoracis

Samples of Longissimus thoracis muscle were taken from the 10th to 13th rib [4 (link)]. Muscle samples were packed into polyethylene bags and stored at −30 °C until analysis. The fatty acid (FA) profile of the fat extracted from the internal part of the muscle was analyzed by gas chromatography (GC) of the methyl-esters derived from the fatty acids of the samples. The fat methylation process was performed by mixing 10 mg of sample with 0.25 mL of a sodium methoxide solution 5% (w/v) in methanol and heating it at 60 °C for 30 min [24 (link)]. The methyl-esters were analyzed and quantified by GC using a Stabilwax (Restek Corp., Bellefonte, PA, USA) capillary column (60 m × 0.25 mm × 0.25 µm; Varian 3400, Palo Alto, CA, USA). The FA peaks were identified through comparison with known reference methyl-esters (Supelco 37 Component FAME Mix, 47885-U, Sigma-Aldrich Co., Bellefonte, PA, USA).