关键词: 肌原纤维水, T2弛豫, 鸡胸肉, 解冻, 肉品质

Abstract: 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.

Key words: myofibrillar water, T2 relaxation, chicken breast, thawing, meat quality