LIPID-COMPOSITION OF PORK MUSCLE IN RELATION TO THE METABOLIC TYPE OF THE FIBERS

The aim of this study was to investigate the relationships between lipid composition and metabolic type of the muscles in pork. Five muscles (Longissimus dorsi, Biceps femoris, Psoas major, Trapezius and Masseter) were chosen in order to cover a broad range of metabolic type. The results showed that: (1) Intramuscular lipid content as well as triglyceride content were not strictly related to the metabolic type; indeed, a glycolytic muscle such as Longissimus dorsi exhibited an intramuscular fat content close to that of an oxidative muscle, Masseter. (2) In contrast, the total phospholipids, phosphatidylethanolamine (PE) and cardiolipin contents were characteristic of the metabolic type. Thus, glycolytic muscles were low in phospholipids (480 mg/100 g), PE (94 mg/100 g) and cardiolipin (24 mg/100 g) as compared to oxidative muscle (860, 264 and 57 mg/100 g), respectively). (3) Except in Longissimus dorsi, fatty acid composition of phospholipids was similar in the four other muscles. Variations in fatty acid composition of triglycerides were not related to metabolic type of the fibres.