Abstract

The objective of this study was to investigate the response of sarcoplasmic proteins in bovine LM to low-voltage electrical stimulation (ES; 80 V, 35 s) after dressing and its contribution to meat tenderization at an early postmortem time. Proteome analysis showed that ES resulted in decreased (P < 0.05) phosphorylation of creatine kinase M chain, fructose bisphosphate aldolase C-A, beta-enolase, and pyruvate kinase at 3 h postmortem. Zymography indicated an earlier (P < 0.05) activation of mu-calpain in ES muscles. Free lysosomal cathepsin B and L activity increased faster (P < 0.05) in ES muscles up to 24 h. Immunohistochemistry and transmission electron microscopy further indicated that lysosomal enzymes were released at an early postmortem time. Electrical stimulation also induced ultrastructural disruption of sarcomeres. In addition, ES accelerated (P < 0.05) the depletion of ATP, creatine phosphate, and glycogen, as well as a pH decline and the more preferred pH/temperature decline mode. Finally, ES accelerated meat tenderization, resulting in lesser (P < 0.05) shear force values than the control over the testing time. A possible relationship was suggested between a change in the phosphorylation of energy metabolic enzymes and the postmortem tenderization of beef. Our results suggested the possible importance of the activation of mu-calpain, phosphorylation of sarcoplasmic proteins, and release of lysosomal enzymes for ES-induced tenderization of beef muscle.

Keywords

mu-calpain; electrical stimulation; lysosomal enzyme; phosphorylation; proteomics; tenderization

Published in

Journal of Animal Science
2012, Volume: 90, number: 5, pages: 1638-1649

SLU Authors

• Lundström, Kerstin

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science


Publication identifier

DOI: https://doi.org/10.2527/jas.2011-4514

Permanent link to this page (URI)

https://res.slu.se/id/publ/43043