宰后不同处理条件下黄牛胴体肌肉理化性质变化

Research of Different Postmortem Condition on Physicochemical Properties Changes of Cattle Carcass Muscle

以牛宰后左侧胴体在2℃条件下冷却24h作为对照组；右侧胴体在2℃条件下冷却4h后，移到10～15℃条件下冷却4h之后再移到2oC条件下继续冷却16h作为处理组，测定了宰后不同胴体冷却温度对肉的理化性质的影响。结果显示，对照组在宰后8h温度降至10qc左右，而处理组在宰后13h降至10℃左右。宰后8h处理组的pH值显著低于对照组。宰后8h，对照组ATP含量显著低于处理组。pH值和ATP含量变化表明，处理组在冷却过程中有生化代谢过程加速阶段。处理组宰后第1天和第7天的剪切力分别与对照组第7天和第21天的剪切力相似。实验结果表明，调节宰后冷却温度可以加速代谢过程，避免强烈的冷收缩，同时可以大幅度缩短牛肉的嫩化时间。

To investigate the physicochemical properties changes of cattle carcass muscle after adjusting postmortem chilling temperatures,the left carcass chilled for 24 h at 2 ℃ was used as the control group,while the right chilled for 4 h at 2 ℃ and 4 h at 10-15 ℃,and then 16 h at 2 ℃ was as the treatment group. It took 8 h for the control group to cool down to approximately 10 ℃ and 13 h for the treatment one. Treatment group had lowered pH than the control at 8 h,muscle at 8 h postmortem had lowered ATP content than that of the control group,changes in treatment group of pH and ATP content suggested that adjusting postmortem chilling temperatures was a set of biochemical metabolism process accelerated phase. The shear force in the carcass of the treatment group at the 1st and the 7 th day was similar to that of the control group at the 7 th day and the 21 st day.The results showed that adjusting postmortem chilling temperatures could effectively avoid the cold shrinking and had significantly shorten the beef meat tenderizer.