Breed-Driven Textural, Structural, and Mechanical Differentiation of Longissimus thoracis Muscle in Bos indicus and...

Beef structuring strategies often centers on fine muscle marbling texture which aligned more closely with Bos taurus muscle architecture. This perspective overlooks the unique texture of the leaner Bos indicus muscle creating the needs to investigate the textural properties of its ribeye steak (Longissimus Thoracis muscle). Bos indicus; high-lean Malaysian Crossbred Brahman and Bos taurus; high-marbled Purebred Japanese Wagyu, by analyzing its structural, mechanical and microscopic differences between pre-cooked and post-cooked states which set at 190°C to 232°C on open-pan broiler. Cooking significantly increased hardness and peak force ratio in both breeds (p < 0.05). Brahman exhibited markedly greater mechanical resistance, with significantly higher hardness and peak force ratios than Wagyu (p < 0.05). In contrast, Wagyu demonstrated lower ΔDent Stress and higher tenderness along the longitudinal orientation, attributed to the cushioning effect of IMF. The anisotropy index and strength difference were significantly greater in Brahman before cooking, indicating stronger fiber alignment and rigidity; although both declined after cooking, Brahman still retained firmer structural properties compared with Wagyu. Cooking yield and fat retention were significantly higher in Wagyu (63.5% and 78.4%) than in Brahman (44.7% and 11.5%), while water retention was slightly higher in Brahman. Outcomes mediated via structural organization and phase distribution within the muscle system. Microscopic assessment confirmed more pronounced fiber collapse in Brahman and marbling-stabilized microstructure in Wagyu samples. Overall, these findings highlighted distinct breed-specific responses to thermal treatment, with Brahman; a Bos indicus beef expressed robustness and greater shrinkage. While Wagyu; a Bos taurus demonstrated superior thermal stability with tenderness, underscoring the structural influence of marbling on cooked meat quality.