Evidence for differences in post mortem intramuscular phospholipase activity in several muscle types

The neutral and polar lipids of chicken adductor longus and pork semitendinosus muscles have been analysed at several periods of post mortem ageing. A complete fatty acid analysis for pork muscle has also been carried out. The results revealed small changes in chicken leg muscle phosphatidyl ethanolamine and free fatty acid fractions, suggesting limited phospholipase A activity in this muscle. The pork muscle showed no changes. The results are considerably different from results obtained for chicken pectoralis major. The differences are discussed in the light of the structural and biochemical differences between the sarcotubular systems of red and white muscle fibres.