冷却排酸期间牛胴体温度与pH的变化及其对牛肉汁液渗出性的影响

为研究牛胴体温度与pH变化规律对牛肉汁液渗出性的影响,本研究对100头秦川牛胴体的前部(脖肉)、中部(外脊)、后部(臀肉)在屠宰后冷却排酸过程中温度与pH随屠宰后时间的变化进行了同步跟踪测定,并对冷却排酸后相应部位肉表面的汁液渗出性加以分析。结果表明,中部胴体温度下降速率最高,分别是前部和后部的1.75和1.45倍。前部胴体pH下降速率最小,中部和后部胴体下降速率分别是前部胴体的6.56和4.88倍,最终pH为前部胴体>中部胴体>后部胴体。而pH下降至6时的温度与汁液渗出性之间具有极好的正相关性,其线性回归方程拟合度R2均达到0.8以上。pH为6时的温度均对汁液渗出性有明显影响。结果提示,胴体温度与pH的相对变化会对肉的持水力产生明显影响。

Temperature and pH Decline of Cattle Carcass and Its Effect on Drip Oozing Rate during Conditioning

In order to investigate the effect of temperature and pH decline on weep of beef,the temperature and pH decline of front(neck),middle(striploin) and rear(rump) of cattle carcass from one hundred Qingchuan cattle was determined,and weep of meat surface after conditioning was also analyzed.The results showed that the rate of temperature decline of middle carcass was the highest,and was 1.76 and 1.45 times of front and rear carcass,respectively.The pH of front carcass decreased slowest,while the rate of pH decline of middle and rear carcass was 6.56 and 4.88 times of front.The rank of ultimate pH was front>middle>rear carcass.There was significant positive relationship between Temperature at pH6 and weep of carcass,with R2 exceeded 0.8.The Temperature at pH6 had significant effect on weep of beef.These results suggest that the relative variation between temperature and pH have significant effect on water holding capacity of beef.