Alnahhas N, Le Bihan-Duval E, Baéza E, Chabault M, Chartrin P, Bordeau T, Cailleau-Audouin E, Meteau K, Berri C
J Anim Sci. 2015 Sep;93(9):4524-31. doi: 10.2527/jas.2015-9100.
The impact of divergent selection based on the ultimate pH (pHu) of pectoralis major (P. major) muscle on the chemical, biochemical, and histological profiles of the muscle and sensorial quality of meat was investigated in broiler chickens. The protein, lipid, DM, glycogen and lactate content, glycolytic potential, proteolysis, lipid and protein oxidation index, muscle fiber cross-sectional area, capillary density, and collagen surface were determined on the breast P. major muscle of 6-wk-old broilers issued from the high-pHu (pHu+) and low-pHu (pHu-) lines. Sensory attributes were also evaluated on the breast (roasted or grilled) and thigh (roasted) meat of the 2 lines. Protein, lipid, and DM content of P. major muscle were not affected by selection ( > 0.05). However, the P. major muscle of the pHu+ line was characterized by lower residual glycogen (-16%; ≤ 0.001) and lactate (-14%; ≤ 0.001) content and lower glycolytic potential (-14%; ≤ 0.001) compared with the pHu- line. Although the average cross-sectional area of muscle fibers and surface occupied by collagen were similar ( > 0.05) in both lines, fewer capillaries per fiber (-15%; ≤ 0.05) were observed in the pHu+ line. The pHu+ line was also characterized by lower lipid oxidation (thiobarbituric acid reactive substance index: -23%; ≤ 0.05) but protein oxidation and proteolysis index were not different ( > 0.05) between the 2 lines. At the sensory level, selection on breast muscle pHu mainly affected the texture of grilled and roast breast meat, which was judged significantly more tender ( ≤ 0.001) in the pHu+ line, and the acid taste, which was less pronounced in the roasted breast meat of the pHu+ line ( ≤ 0.002). This study highlighted that selection based on pHu does not affect the chemical composition and structure of breast meat. However, by modifying muscle blood supply and glycogen turnover, it affects meat acidity and oxidant status, both of which are likely to contribute to the large differences in texture observed between the 2 lines.
在肉鸡中研究了基于胸大肌最终pH值（pHu）的差异选择对肌肉的化学、生化和组织学特征以及肉的感官品质的影响。测定了来自高pHu（pHu+）和低pHu（pHu-）品系的6周龄肉鸡胸大肌中的蛋白质、脂质、干物质、糖原和乳酸含量、糖酵解潜力、蛋白水解、脂质和蛋白质氧化指数、肌纤维横截面积、毛细血管密度和胶原蛋白表面积。还对这两个品系的胸肉（烤制或炙烤）和大腿肉（烤制）的感官特性进行了评估。胸大肌的蛋白质、脂质和干物质含量不受选择的影响（P>0.05）。然而，与pHu-品系相比，pHu+品系的胸大肌具有较低的残余糖原含量（-16%；P≤0.001）和乳酸含量（-14%；P≤0.001）以及较低的糖酵解潜力（-14%；P≤0.001）。尽管两个品系中肌纤维的平均横截面积和胶原蛋白所占表面积相似（P>0.05），但在pHu+品系中观察到每根纤维的毛细血管较少（-15%；P≤0.05）。pHu+品系的脂质氧化也较低（硫代巴比妥酸反应物质指数：-23%；P≤0.05），但两个品系之间的蛋白质氧化和蛋白水解指数没有差异（P>0.05）。在感官层面，对胸肌pHu的选择主要影响炙烤和烤胸肉的质地，pHu+品系的质地被判定明显更嫩（P≤0.001），以及酸味，pHu+品系烤胸肉中的酸味不太明显（P≤0.002）。这项研究强调，基于pHu的选择不会影响胸肉的化学成分和结构。然而，通过改变肌肉血液供应和糖原周转率，它会影响肉的酸度和氧化状态，这两者都可能导致两个品系之间观察到的质地差异很大。
