不同贮藏温度下宰后羊肉的肉质变化及其影响因素

Variation of postmortem lamb quality and its influencing factors in different store temperatures

为研究宰后羊肉中一磷酸腺苷活化蛋白激酶(AMPK)的活化程度对糖酵解进而对肉质的影响,探讨肌肉宰后成熟的机理。将宰后羊肉分别放置在0、4和15℃下保存,在保存后的0～24h内测定羊肉的AMPK活性、肌糖原(mg/g)、pH值和乳酸(μmol/g),在保存后的0～7d内测定羊肉的剪切力、熟肉率、肌原纤维小片化指数(MFI)和肉色的变化。结果表明,保存在15℃的羊肉具有最高的AMPK活化值(P<0.05),肌糖原和pH值下降快,乳酸蓄积多,剪切力的回降速度和熟肉率的回升速度快,MFI高,肉色变差最快。这说明宰后羊肉的保存温度越高,AMPK越容易被激活,肉的糖酵解和成熟速度越快。

In order to research the effect of AMPK activation degree on glycolysis, and further on meat quality, the mechanism of postmortem maturation was analyzed. The postmortem lamb preservated at 0, 4 and 15℃, AMPK activity, muscle glycogen, pH value and lactic acid were measured at 0–24 h after preservation, and shearing force, cooked meat percentage, myofibril fragmentation index (MFI) and meat color were measured at 0–7d after preservation. The results showed that the lamb muscle which were preservated at 15℃ had the maximum AMPK activity (P<0.05), fast decreasing speed of glycogen and pH value, more lactic acid accumulation, rapid speed of shearing force rally and cooked meat percentage drawdown, higher MFI and worse meat color. This showed much higher preservation temperature, more easily AMPK activation and rapidly glycolysis and mature speed of postmortem lamb.