LAUSR

BACKGROUND This study aimed to identify relationships between components of intramuscular connective tissue, the proportions of the different fiber types, intramuscular fat and sensory tenderness of beef cooked at 55°C. For that, four muscles differing in their metabolic and contractile properties as well as in their collagen content and butcher value, from dairy and beef cattle of several ages and sexes were used in order to create variability. RESULTS Correlation analyses and/or stepwise regressions were applied on Z-scores to identify the existing and robust associations. Tenderness scores were further categorized into tender, medium and tough classes using unsupervised learning methods. The findings revealed a muscle-dependant role on tenderness of total and insoluble collagen, cross-links and of type IIB+X and IIA muscle fibers. The Longissimus thoracis and Semitendinosus muscles that, in this study, were extreme in their tenderness potential were very different from each other and of the Rectus abdominis (RA) and Semimembranosus (SM). RA and SM muscles were very similar for their relationship for muscle components and tenderness. A relationship was present between marbling and tenderness only when the results were analysed irrespective of all the factors of variations of experimental model that are muscle and animal type. CONCLUSION The statistical approaches applied in this trial performed using the z-scores allowed to identify the robust associations between muscle components and sensory beef tenderness and also to found discriminatory variables of beef tenderness classes. This article is protected by copyright. All rights reserved.