蒸煮时间对滩羊肉蒸煮损失、嫩度及水分分布的影响

为了探究蒸煮时间对滩羊肉蒸煮损失、嫩度及水分分布的影响。对不同蒸煮时间处理下的滩羊肉蒸煮损失、剪切力进行测定,并结合低场核磁技术研究滩羊肉水分子T_2弛豫特性以及各指标间的相关性。结果表明:随着蒸煮时间的延长,滩羊肉的蒸煮损失和剪切力先增大后减小(P0.05)。LF-NMR检测到了4个明显的水分群,代表肉中的弱结合水(T_(21))、强结合水(T_(22))、不易流动水(T_(23))和自由水(T_(24))4种存在状态。延长蒸煮时间,弛豫时间先变长后缩短,T_(23)含量先减少后增加,T24含量先增加后减少。核磁成像结果显示,蒸煮时间的延长会使图像的亮度先增强后减弱。相关性分析结果表明,蒸煮损失与T_(23)、T_(24)呈显著正相关(P0.05),相关系数分别为0.966,0.994;剪切力与T_(23)呈显著正相关(P0.05),相关系数为0.846,与T23峰面积比例呈显著负相关(P0.05),相关系数为-0.504。说明不同蒸煮时间处理下的滩羊肉的蒸煮损失、嫩度及水分分布均具有显著的变化,且各指标之间具有显著的相关性。

Effect of cooking loss, tenderness and water distribution of Tan sheep at

The present study was undertaken to investigate the effects of different salt addition treatment on the cooking loss, tenderness and water distribution of Tan sheep. Cooking loss, shear force were mesured and T₂ relaxation properties of water molecules by low-field NMR technology were assayed in the different treatment, the correlation among these indexes and changes of water distribution in Tan sheep with different cooking time treatment were also discussed. The results show: both cooking loss and shear force significantly increase at first and then decrease (P<0.05) as cooking time goes on. LF-NMR detects four distinct water populations which represent four presence status of water in meat: weakly bound water, strongly bound water, immobilized water and free water. Extending the cooking time, the relaxation time firstly extends and then reduces, the proportion of immobilized water firstly decreases and then increases, the content of free water firstly increases and then decreases. NMR images show that sample brightness changes from bright to weak as cooking time goes on. Correlation analysis shows that there is a significant positive correlation between cooking loss and T₂₃, T₂₄, and the correlation coefficient were 0.966, 0.994, a same correlation between shear force and T₂₃ too, the correlation coefficient was 0.846, and a significant negative correlation between shear force and peak area fraction of T₂₃, the correlation coefficient was -0.504. These results indicate that different cooking time significantly affects the cooking loss, shear force and water distribution of Tan sheep, also, a significant correlation among these indexes.