2.7. Intramuscular fat and fatty acid analysis
After LTL and SCF sampleswere fast-thawed in tapwater (4 h,without losing vacuum), they were ground and the fat was extracted in chloroform–methanol, with 2,6-di-tert-butyl-4-methylphenol (BHT) as an antioxidant (Bligh & Dyer, 1959). One millilitre of chloroform phase was used to assess the percentage of intramuscular fat (IMF) and subcutaneous fat (SCF) by drying at 100 °C for 20min and the results were expressed as the weight percentage of wet muscle and adipose tissue. The methyl esters from fatty acids (FAMES) were formed using a KOH solution in methanol. The FAMES were analysed in a gas chromatograph HP-6890 II (Hewlett-Packard, Waldbronn, Germany), with a capillary column SP-2380 (100m×0.25mm×0.20 μm), using nitrogen as the carrier gas. Fatty acid composition was quantified using heneicosanoic acid (C21:0) as the internal standard