秦川牛宰后肉色与其食用品质的相关性

为研究宰后牛肉肉色变化与其食用品质的相关性，以秦川牛背最长肌为研究对象，对宰后排酸成熟7d牛肉的肉色、肌红蛋白相对含量、pH值、剪切力、持水力及蒸煮损失率的变化进行分析，采用主成分分析和相关性分析相结合的方法研究肉色与其食用品质的相关性。结果表明：排酸过程中牛肉亮度值（L*）和红度值（a*）呈现先上升后下降的趋势，黄度值（b*）缓慢上升；氧合肌红蛋白（oxymyoglobin，OxyMb）相对含量持续下降；脱氧肌红蛋白（deoxymyoglobin，DeoxyMb）相对含量先上升，5d后缓慢下降；高铁肌红蛋白（metmyoglobin，MetMb）相对含量逐渐上升；pH值先降低，5d后回升；持水力和剪切力逐渐减小；蒸煮损失率先呈上升趋势，7d后下降；L*与DeoxyMb相对含量呈极显著正相关（P＜0.01），OxyMb相对含量与MetMb相对含量呈极显著负相关（P＜0.01），MetMb相对含量与剪切力呈显著负相关（P＜0.05），持水力与剪切力呈显著正相关（P＜0.05），OxyMb相对含量与持水力和剪切力呈显著正相关（P＜0.05），MetMb相对含量与持水力呈极显著负相关（P＜0.01）。

Correlation between Meat Color and Eating Quality of Qinchuan Cattle after Slaughter

This study investigated the correlation between changes in beef color and eating quality during postmortem aging. Changes in the meat color, relative content of myoglobin, pH value, shear force, water-holding capacity, cooking loss of Longissimus dorsi muscles from Qinchuan cattle aged for different periods up to 7 days after slaughter were examined and the relationship between meat color and eating quality was evaluated using principal component analysis and correlation analysis. The results showed that the brightness value (L*) and redness value (a*) of beef increased first and then decreased, while the yellowness value (b*) increased gradually and slowly. The relative content of oxymyoglobin (OxyMb) continued to decline, the relative content of deoxymyoglobin (DeoxyMb) rose until the fifth day, and afterward declined slowly, and the relative content of metmyoglobin (MetMb) increased gradually. The pH value showed a decrease until the fifth day and then rose. Both the water-holding capacity and shear force gradually decreased, and the cooking loss first showed an upward trend, and then decreased on the seventh day. L* was significantly positively correlated with the relative content of DeoxyMb (P < 0.01). The relative content of MetMb was correlated significantly negatively with the relative content of OxyMb and water-holding capacity (P < 0.01) as well as shear force (P < 0.05). There was a significantly positive correlation between water-holding capacity and shear force (P < 0.05), and both parameters were significantly positively correlated with the relative content of OxyMb (P < 0.05).