加热温度对酱卤牛肉质构特性及水分分布的影响

采用质地剖面分析法（texture profile analysis，TPA）和低场核磁共振（low-field nuclear magnetic resonance，LF-NMR）技术研究不同加热温度（50、60、70、80、90、98 ℃）下二次加热酱卤牛肉的质构特性和水分分布变化。结果表明：随着加热温度的升高，酱卤牛肉的硬度、咀嚼度和黏附性均呈先增大后下降趋势，均在90 ℃时达到最大值（P＜0.05）。LF-NMR结果显示存在4 种水分群，随着加热温度的升高，不易流动水弛豫时间T23逐渐缩短，峰面积逐渐减小，自由水弛豫时间T24逐渐缩短，峰面积逐渐增大（P＜0.05）。结果表明，熟肉制品蒸煮受热后的质构指标与水分分布随着加热温度的变化呈规律性变化，低温时肉样相对松软，结合水含量较高，高温时肉样硬度和自由水含量相对较高。

Effect of Reheating Temperature on Texture Properties and Moisture Distribution of Sauced Beef

The effect of different reheating temperatures (50, 60, 70, 80, 90 and 98 ℃) on texture properties and moisture distribution of sauced beef were studied by using texture profile analysis (TPA) and low-field nuclear magnetic resonance (LFNMR). The results showed that the hardness, chewiness and adhesiveness increased with reheating temperature up to 90 ℃ followed by a decrease (P < 0.05). LF-NMR showed the existence of four water populations. With increasing reheating temperature, the relaxation time of T23 and peak area decreased; the relaxation time of T24 decreased, while the peak area increased (P < 0.05). The above results demonstrated that the texture properties and moisture distribution of the cooked meat changed regularly with reheating temperature. At lower temperatures, the meat sample was relatively soft with more bound water, while at higher temperatures, it became relatively hard with higher proportion of free water.