基于低场核磁共振探究解冻过程中肌原纤维水对鸡肉食用品质的影响

本研究旨在基于低场核磁共振横向弛豫时间T2分析解冻过程中肌原纤维水的分布及流动性与鸡肉食用品质间的关联性。以冷鲜鸡胸肉（宰后32 h）为对照，采用冷藏解冻、微波解冻（微波-1、微波-2）与超声解冻（180、200 W）5 种不同方式解冻中心温度为－20 ℃的冻结鸡胸肉，测定肉样T2、品质特性指标并分析它们之间的相关性。结果显示：解冻过程中肉样的T2水分分布情况发生明显变化，与对照组相比，除微波-2解冻外，其余4 组解冻肉样均发生不易流动水T22（40～50 ms）向自由水T23（100～250 ms）迁移；同时，微波-2解冻与200 W超声解冻出现强结合水水分群T20（0～0.1 ms）；相关性分析表明，T20、T21和T22峰比例与肉样的持水能力、嫩度和多汁性呈极显著正相关（P＜0.01），与解冻损失率、蒸煮损失率呈显著（P＜0.05）或极显著（P＜0.01）负相关；剪切力与T20峰比例呈显著负相关（P＜0.05），与T22峰比例呈极显著负相关（P＜0.01）。解冻方式对肉样的外观和风味无显著影响（P＞0.05），微波-2解冻肉样的质地与多汁性评分最接近于对照组，整体可接受性更高；冷藏解冻与超声解冻肉样的质地与多汁性更差，整体可接受性也更低。因此，本项研究结果表明在解冻过程中肌原纤维水的迁移情况对鸡肉品质具有显著影响，并且微波-2解冻程序能够更好地抑制解冻过程中肉品质的下降。

Effect of Myofibrillar Water on Chicken Quality during Thawing as Studied by Low-Field Nuclear Magnetic Resonance

The purpose of this study was to analyze the relationship between myofibrillar water distribution and mobility and chicken meat quality during thawing by transverse relaxation times (T2) of low-field nuclear magnetic resonance (LF-NMR). Chilled chicken breast (32 h after slaughter) was used as the control and frozen chicken breast with a core temperature of ?20 ℃ was thawed by five different methods: refrigeration, microwave (modes 1 and 2) and ultrasonic (180 and 200 W). The distribution of water T2 relaxation times and quality characteristics of meat samples were measured, and the correlation between them was analyzed. The results showed that during the thawing process, the T2 distribution in meat samples changed significantly; compared with the control group, the immobilized water (T22, 40–50 ms) in all treatment groups except for microwave 2 was transformed into free water (T23, 100–250 ms). Thawing by microwave 2 and 200 W ultrasonic resulted in the emergence of the strongly bound water population (T20, 0–0.1 ms). The correlation analysis showed that the area proportions of T20, T21, and T22 peaks were significantly positively correlated with the water-holding capacity (WHC), tenderness and juiciness of meat samples (P < 0.01), and were significantly negatively correlated with thawing loss and cooking loss (P < 0.05 or 0.01). Shear force was significantly negatively correlated with the area proportion of T20 (P < 0.05) and T22 (P < 0.01) peaks. The thawing methods had no significant effect on the appearance or flavor of meat samples (P > 0.05). The microwave 2 thawed meat sample had the closest texture and juiciness to the control group, and was higher in overall acceptability, while the opposite was observed for the thawed meat samples from refrigeration and ultrasonic treatment. Therefore, the mobility of myofibrillar water during thawing has a significant impact on the quality of chicken meat, and microwave 2 can better prevent meat quality deterioration during thawing.