低场核磁共振技术检测猪肉加热终点温度

Detection of endpoint temperature of pork by low field nuclear magnetic resonance

目的建立一种基于低场核磁共振技术的猪肉加热终点温度快速检测方法。方法选择猪背部最长肌于宰后24 h内分别加热至中心温度为40、50、60、70和80℃(生肉20℃作为对照),冷却24 h后测定低场核磁共振横向弛豫时间(T_2)、蒸煮损失率(cooking loss,CL)。结果随着加热终点温度升高,蒸煮损失率显著增加,低场核磁共振T_2谱中第2个峰的峰时间T_(21)和峰面积比P_(21)值差异显著(P<0.05)。因此,T_(21)、P_(21)、CL可作为检测猪肉不同加热终点的指标。结论研究表明不同加热终点温度的猪肉样品,低场核磁共振的参数T_(21)、P_(21)以及蒸煮损失的变化有一定规律性,可用线性回归模型进行预测。该法可用于猪肉加热终点温度的快速检测。

Objective To establish a rapid method for determination the endpoint temperature （EPT） of pork by low field nuclear magnetic resonance （LF-NMR）. Methods Longissimus dorsi muscles of pork were taken and cooked to a center temperature of 40, 50, 60, 70 and 80 ℃ （the raw sample 20 ℃ as control）. The cooked pork was cooled for 24 h and then cooking loss （CL） and low-field nuclear magnetic resonance transverse relaxation time （T2） were measured. Results As cooking EPT increased, CL tended to be increased, and T21 and P21 changed significantly （P〈0.05）. Therefore, T21, P21 and CL could be used as indicators to detect different EPTs of pork. Conclusion The results show that LF-NMR parameters of T21 and P21 and CL of pork with different EPTs have a certain regularity, which can be predicted by linear regression models. The established method can be used for rapid detection of EPT of pork.