Relationship between meat quality and collagen crosslink concentrations in beef from calf-fed, yearling-fed and mature cattle

Abstract

s published in Meat Science from the 2014 CMSA / CMC Abstracts are published in cooperation with the Canadian Meat Science Association / Canadian Meat council and have been subject to the Societies own review process and have not been peer reviewed by the Editorship of the journal Pyridinoline (PYR) and Ehrlich's chromogen (EC) are well-known mature collagen crosslinks associated with the toughness of high connective tissue beef. The hypothesis that the concentration of PYR increases and that of EC decreases with cattle age was investigated in a study involving calf-fed steers (n = 14), yearling-fed Hereford–Aberdeen Angus or Charolais–Red Angus steers (n = 14) and similarly bred mature cows (n = 12) slaughtered at 12, 20 and 73 months of age, respectively. Semitendinosus (ST) and gluteus medius (GM) muscles were harvested 24 h post mortem and stored frozen until meat quality and connective tissue analyses. Meat quality analyses indicated that for the ST mean muscle ultimate pH values did not differ among age groups and cow ST showed lower purge loss and L* (increased darkness) and b* values (decreased yellow) and higher a* values (increased redness) than calf and yearling ST. For the GM, mature cows had lower mean ultimate pH, L* (darker meat) and b* (decreased yellowness) values, and lower purge and cooking http://dx.doi.org/10.1016/j.meatsci.2014.07.017 0309-1740/© 2014 Elsevier Ltd. All rights reserved. losses than yearling and calf GM. Intramuscular fat was significantly (P b 0.05) lower in cow than in calf and yearling muscle for both ST and GM muscles. Shear force did not differ between age groups for the GM but ST shear force values were significantly higher for mature cows. Total collagen content for the GM was not different between age groups but yearling cattle showed higher total collagen in the ST than in the other age groups and ST mean total collagen content was higher than that in the GM. PYR concentration (mol PYR/mol collagen) did not changewith animal age in the ST or GM, although total amounts of PYR in eachmuscle increased with age due to increases in total collagen with age. EC concentrations (mol EC/mol collagen) in both ST and GM decreased with animal age and were negatively correlated with shear force. Results indicated that total collagen rather than PYR crosslink density increasesmeat toughnesswith animal age and the decline in EC concentration suggests that it may be replaced by another crosslink as muscles mature.