Bianchi M, Fletcher D L, Smith D P
Department of Food Science, University of Bologna, 47023 Cesena, Italy.
Poult Sci. 2005 May;84(5):803-8. doi: 10.1093/ps/84.5.803.
The functional and physical properties of intact and ground meat were determined during 4 replicate trials on a total of 180 pale [lightness (L*) > 53] and normal (46 < L* < 53) boneless, skinless breast fillets collected from 2 commercial processing plants. At 24 h postmortem, L*, redness (a*), yellowness (b*), and pH were determined on each fillet. The left fillet from each breast was ground and used to determine cook loss (CL) and Allo-Kramer (AK) shear on meat patties as well as moisture uptake (MU) and CL on meat slurries before and after adjustment to the normal meat pH of 5.9. The right fillet from each breast was kept intact and used to determine expressible moisture (EM), CL, and AK shear on the intact meat. Compared with normal fillets, pale fillets exhibited significantly higher L* values, lower ultimate pH (5.67 vs. 5.94), higher AK (3.5 vs. 2.9 kg/g), higher EM, lower MU, and higher CL measured on the intact fillets, ground meat patties, and meat slurries. Adjustment of the pH of the pale meat slurries to normal meat pH (5.9) resulted in a higher MU (11.05 vs. 3.69%), indicating a partial restoration of protein functionality. These results indicate that wide differences in raw broiler breast meat color, mainly due to differences in the muscle pH, are related to important variations in the water-holding and binding capacities of the meat. The effect of low meat pH can be partially ameliorated in ground meat by pH adjustment.
在来自2家商业加工厂的总共180块浅色(亮度值(L*)>53)和正常(46<L*<53)的去骨、去皮鸡胸肉上进行了4次重复试验,测定了完整肉和绞碎肉的功能和物理特性。宰后24小时,测定每块鸡胸肉的L值、红度(a)、黄度(b*)和pH值。将每块鸡胸肉的左半部分绞碎,用于测定肉饼的煮损失(CL)和阿洛-克莱默(AK)剪切力,以及在调整至正常肉pH值5.9前后肉浆的水分吸收(MU)和CL。每块鸡胸肉的右半部分保持完整,用于测定完整肉的可表达水分(EM)、CL和AK剪切力。与正常鸡胸肉相比,浅色鸡胸肉在完整鸡胸肉、绞碎肉饼和肉浆上测得的L*值显著更高,最终pH值更低(5.67对5.94),AK值更高(3.5对2.9 kg/g),EM更高,MU更低,CL更高。将浅色肉浆的pH值调整至正常肉pH值(5.9)会导致MU更高(11.05%对3.69%),表明蛋白质功能部分恢复。这些结果表明,生鸡胸肉颜色的巨大差异主要归因于肌肉pH值的差异,这与肉的持水和结合能力的重要变化有关。通过pH值调整,绞碎肉中低肉pH值的影响可部分得到改善。