Postmortem proteolysis in longissimus muscle from beef, lamb and pork carcasses.

Abstract

Postmortem proteolysis in skeletal muscle and factors affecting this process were examined in pork, lamb and beef longissimus muscles (LM) to determine the cause of differences in meat tenderness among these species. Fat thickness differed among species in the following order: pork greater than beef greater than lamb. The following patterns were observed for rate of temperature and pH decline: lamb greater than pork greater than beef and pork greater than beef greater than lamb, respectively. At 1 d postmortem, pork was the most tender, followed by beef and lamb, respectively. Between 1 and 14 d of postmortem storage, lamb LM was the most improved in tenderness, followed by beef and pork, respectively. Species did not differ (P greater than .05) in LM collagen solubility. Pork LM from fed pigs had the highest (P less than .05) level of cathepsins B + L and cystatin(s) activities, whereas no differences (P greater than .05) were observed among the species for cathepsin B activity. The lowest (P less than .01) Ca2(+)-dependent protease (CDP)-II and CDP inhibitor activities were observed in pork LM. Beef LM had the highest CDP inhibitor activity (P less than .05) but was intermediate in CDP-II activity. No differences were observed among species for CDP-I activity. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrils isolated at 0, 1 and 14 d postmortem indicated that by d 1, desmin hydrolysis was most extensive in pork muscle, followed by lamb and beef.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of nutritional factors on biochemical, structural and metabolic characteristics of muscles in ruminants, consequences on dietetic value and sensorial qualities of meat

“…Indeed, it has been shown that the enzyme/inhibitor ratio influences the tenderisation rate [87]. The µ−calpain/calpastatin ratio, increasing when ATPase activity increases, is equal to 1/4, 1/2.5 and 1/1.5 for beef, lamb and pork respectively [54] which can partly explain the lower tenderisation rate in beef.…”

“…Then, ruptures in the sarcomere structure occur and tenderisation of meat proceeds [51]. Although several proteolytic systems have been described in the literature (calpaines, proteasome, cathepsines), calpains (µ and m), Ca 2+ -dependent enzymes seem to play a major role [54]. These enzymes specifically degrade certain inter-and intramyofibrillar cytoskeleton proteins such as desmin, nebulin and partly connectin, at the I band and Z disk locations of the sarcomere.…”

Different phenotypic and proteomic markers explain variability of beef tenderness across muscles

“…The role of calpains (M-and μ-calpain) in proteolysis is well-known (Koohmaraie, Whipple, Kretchmar, Crouse, & Mersmann, 1991). So, their implication in the tenderness classes discrimination was not a surprise.…”

Boz Irk Sığırın Et Gevrekliğini Belirlemede CAST ve CAPN1 Genlerindeki Kimi SNP’lerin Kullanımı

“…Lee et al [27] who worked on Hanwoo cattle found the average SF as 5.803±0.275 kg cm 2 , for the heifers as 6.598±0.265 kg/cm 2 , for the bulls as 7.200±0.275 kg/cm 2 and 3.400±0.061 kg/cm 2 for calves. Soysal [28] who worked on the texture of beef stated that gender and muscle factor do not seem to be statistically significant (P>0.05).…”

“…CAST prevents μ-and m-Calpain activity and regulates postmortem proteolysis. There is a linear correlation between the calcium activity after death and the meat tenderness [2] . Many studies show that CAPN-CAST system is important to the normal development of skeletal muscles.…”