Effects of biological type and dietary fat treatment on factors associated with tenderness: I. Measurements on beef longissimus muscle

Abstract

The objective was to evaluate chemical, mechanical, and sensory attributes associated with tenderness in divergent cattle breeds--Wagyu (W; n = 12), Limousin (L; n = 12) and F1-cross (WxL; n = 12)--fed two dietary treatments (0 or 6% sunflower oil (DM basis)). A randomized complete block repeated measures design in a 3 x 2 factorial arrangement of treatments was used, and effects of breed, diet, block, and associated interactions were tested. Cattle were fed barley-based diets for an average of 259 d. Twenty-four hours postmortem (PM), steaks from the longissimus muscle (LM) were sliced, vacuum-packaged, aged (1, 3, 7, 14, 28, and 56 d PM) at 2 degrees C, and frozen (-40 degrees C) until analyzed. Wagyu steaks had lower (P < 0.05) Warner-Bratzler shear force (WBSF) values than L steaks across all aging times. At 1 d PM, W steaks required slightly more (P > 0.05) force to shear than WxL or L (0.30 and 0.11 kg, respectively); however, by d 14 PM, W steaks required 0.77 kg less (P < 0.05) force to shear than L. Wagyu steaks received higher (P < 0.05) sensory panel sustained tenderness scores at d 14 PM than L. The pH decline was slower (P < 0.05), and temperature decline more (P < 0.05) rapid, in W carcasses than L or WxL carcasses. Breed and diet did not affect (P > 0.10) free calcium levels (FCL) over time (0, 1, 3, 7, and 14 d PM), 0-h calpastatin activity (CA), d-1 percent collagen (OH-PRO), or d-1 collagen cross-linking (HP). Western blot analysis for the presence of the troponin-T (TNT) 30-kDa fragment, conducted only on samples from steers fed the 0% sunflower oil diet, demonstrated more proteolysis by d 3 PM in L than W or WxL. Overall, breed differences in mechanical and sensory measures of tenderness were not explained by FCL, CA, OH-Pro, and HP. Even though the initial appearance of the TNT 30-kDa fragment was greater in L, linear slopes for appearance of TNT degradation product across aging time were greater for W and WxL (P < 0.01 and P = 0.056, respectively) than for L, suggesting that tenderness differences due to breed may have been facilitated by more-rapid proteolytic degradation over time.

Effects of breed, muscle type, and frozen storage on physico-chemical characteristics of lamb meat and its relationship with tenderness

“…The contribution of this fibrous protein to tenderness is dependent on collagen content, collagen solubility, and extent of its cross-linking (Kuber et al, 2004). Except that, meat eating quality traits such as tenderness, flavor, and juiciness are also known to be linked to fat levels (Lambe et al, 2009).…”

A Limousin specific myostatin allele affects longissimus muscle area and fatty acid profiles in a Wagyu-Limousin F2 population1,2

“…This increased ratio has human health implications in terms of overall health and decreasing coronary heart disease (McDonald, 1991). Experimental comparisons of Limousin and Wagyu germplasm indicate decisive breed differences with respect to carcass attributes (Kuber et al, 2004;Pitchford et al, 2006). Wagyu cattle are smaller framed, have more marbling, and take considerably longer to finish in a feedlot than Limousin, making them less desirable from a production standpoint.…”

Calidad de la carne de las especies domésticas

“…Resultante de la resistencia de dos fuerzas: la relacionada con el tejido conectivo y la relacionada con el tejido miofibrilar. La textura depende de un gran número de factores biológicos intrínsecos, tales como: genética del animal, raza, edad, sexo, régimen de alimentación y tipo de músculo, así como la madurez fisiológica del animal al momento de la matanza, factores de manejo de los animales antes de la matanza y de las condiciones post-mortem de la canal y de la carne (Kuber et al, 2004;Hui et al, 2006).…”