加热温度和含水量对猪肉及其蛋白质特性的影响

Effect of Heating Temperature and Moisture Content on Properties of Pork Meat and Myofibrillar Protein

比较加热过程中不同含水量猪肉部分物理化学特性(蒸煮损失、pH值)、质构参数(硬度、咀嚼性及弹性)及剪切力的变化,并测定分析猪肉中蛋白质特性(溶解性、表面疏水性及巯基含量、热降解情况)受热后的变化,探讨不同含水量猪肉加热后质构特性变化差异的内在机制。结果表明:含水量降低导致加热后肉样的硬度、咀嚼性显著增大(P<0.05),其峰值对应的加热温度高于对照样,并随含水量降低逐渐升高;不同含水量肉样的剪切力随加热温度升高的变化趋势不同,含水量越低,差异越明显。对比研究不同含水量猪肉加热过程中蛋白质部分特性的变化,表明脱水导致猪肉中的蛋白质结构发生变化,热稳定性增强,且含水量越低效果越明显,部分程度上造成脱水猪肉与鲜肉受热后质构特性的差异。

To investigate the mechanism causing differences in texture properties between pork samples with various water contents after being cooked, this study compared changes in physicochemical properties(cooking loss and pH value), texture properties(hardness, chewiness and springiness) and shear force value of pork meat with various moisture contents during heating, and it also measured changes in properties(solubility, surface hydrophobicity, sulfhydryl content and heatinduced degradation) of pork myofibrillar protein. The results showed that decreasing the water content in pork resulted in a significant increase of hardness and chewiness(P<0.05), and the temperature providing maximum hardness and chewiness was higher than that for the control sample and increased with the decrease of water content. The pork samples with various water contents showed different tendencies in shear force value with increasing temperature, and the lower the water content, the more significant the difference. A comparison of the changes in some properties of protein in pork samples with various water contents during cooking showed that dehydration caused structural changes pork myofibril protein and enhanced its heat stability, and the effect was more marked with the decrease of water content, which may be partly responsible for the difference in texture properties between dehydrated and fresh pork.