title: The effects of conditioning on meat collagen: Part 2-Direct biochemical evidence for proteolytic damage in insoluble perimysial collagen after conditioning.
abstract: The effect of proteolytic attack on unwashed and 6 M urea washed bovine perimysial collagen was examined using model systems. Pepsin and cathepsin solubilized collagen continuously over 24h (r = 0·95 andr = 0·88 for time course of pepsin and cathepsin solubilized collagen). Insoluble perimysium treated with pepsin over 24 h resulted in little damage to the insoluble collagenous residue remaining, as evidenced by one-dimensional SDS-polyacrylamide gel electrophoresis. Insoluble perimysium treated with cathepsin resulted in changes to the major peptide bands which were evident after 24 h treatment, visible as broadening and 'fuzziness' of bands, decreased staining intensity, loss of high molecular weight material and a significant reduction in quantity of all peptides when compared with untreated perimysium. The effects of proteolytic action on bovine perimysial collagen in vitro and in conditioned meat were investigated by means of two-dimensional polyacrylamide gel electrophoresis, which provided a more sensitive technique for elucidating changes than the one-dimensional method. The peptide maps obtained from conditioned insoluble perimysium and from insoluble perimysium treated with cathepsin for 24 h were altered relative to the unconditioned insoluble perimysium, with the loss of some peptides and generation of others. The in vitro case was extreme, but was comparable with samples of perimysium from conditioned muscles. The results provide direct biochemical evidence for the presence of proteolytic damage in the insoluble perimysial collagen matrix of meat after conditioning.
authors: Food Studies Division, Department of Catering and Hotel Management, Dorset Institute of Higher Education, Poole, Dorset, BH12 5BB, UK.
authors: C
authors: C
authors: Stanton
authors: N
authors: N
authors: Light