title: Liberation of peptides during meat storage and their interaction with proteinase activity.
abstract: The content of nitrogenous material extracted in perchloric acid from kid longissimus lumborum (LL), semimembranosus (Sm) and triceps brachii (TB) muscles increased 30% during storage for three weeks at 4 °C. The extract of fresh muscle contained a range of molecular sizes up to 13 kDa, the majority less than 4 kDa. The amount of the larger polypeptides (> 4 kDa) extracted from meat decreased to 50% of its initial level in meat stored for five days and to 20% after 25 days. The amount of intermediate sized peptides (1.9 to 4 kDa) remained largely constant throughout storage of meat of normal pH, whilst in meat of high ultimate pH, they showed a transitory increase during the first two weeks storage. Smaller size peptides increased with storage time; increasing more slowly in meat of high ultimate pH. This time-dependent pH effect indicates a sequential autolysis involving neutral followed by acidic proteolytic and peptidic activity. Calpain from beef muscle degraded peptides in the extract and the extract acted as a competitor against a synthetic substrate. This implies that the in-situ autolysis and tenderisation of meat postmortem could be reduced by peptide products.
authors: ENSAIA, 54505 Vandoeuvre-lès Nancy, France.
authors: C
authors: C
authors: Feidt
authors: J
authors: J
authors: Brun-Bellut
authors: E
authors: E
authors: Dransfield