低场核磁共振分析冰温牛肉中不同状态水分变化

LF-NMR Studies of Variations of Different Water States during Controlled Freezing Point Storage of Beef

利用低场核磁共振技术研究冰温贮藏条件下无包装与真空包装牛肉在贮藏过程中水分弛豫参数的变化规律。通过驰豫测定,结果显示新鲜牛肉中有3种不同活动状态的水分,即结合水、不易流动水和自由水,其对应的横向弛豫时间分别是T21、T22、T23。对弛豫参数与常见肉品质指标进行皮尔逊相关系数分析,揭示了两者间的相关性。结果表明:无包装牛肉自由水弛豫参数与其品质指标均有较强的相关性,而真空包装牛肉的弛豫参数与其品质指标的相关性均不强。对冰温贮藏牛肉的品质影响最大的水分是自由水,自由水的弛豫参数能够很好的用于无包装牛肉常规品质指标的研究。

The aim of this study to apply low field NMR to investigate regular variations of different relaxation parameters of water in vacuum packaged beef and non-vacuum packaged beef during controlled freezing point storage. NMR relaxation data indicated that there were three different types of water in fresh beef, namely bound water, free water and immobilized water with relaxation times of T21, T22 and T23 （x-axis）, respectively. Correlation anaysis of three relaxation parameters and meat quality indices was conducted by measuring pearson correlation coefficients. Our results showed that the correlations between the studied relaxation parameters and meat quality indices were strong in non-vacuum packaged beef but not strong in acuum packaged beef. Free water had the biggest influce on meat quality during controlled freezing point storage of beef. The relaxation parameter of free water may hold great promise for potential applications to study quality indices of non- vacuum packaged beef.