冻融循环下鸡肉品质变化的低场核磁共振研究

Changes in Quality Indexes of Chicken Breast Determined by LF-NMR during Freezing-thawing Cycles

运用1H低场核磁共振(LF-NMR)技术研究鸡肉反复冻融过程中的水分变化,并分析该变化与食用品质间的联系。由NMR T2弛豫测定结果可知肌肉中含有3个水群,即结合水、不易流动水和自由水,横向弛豫时间依次为T2b、T21、T22,其中T21与冻融次数显著相关(P<0.05),且与反映肌肉持水性变化的指标间高度相关。冻融后鸡肉食用品质发生显著变化,在贮运过程中需要尽可能避免这一现象。研究表明LF-NMR可用于流通过程中冻鸡肉品质的在线评价。

Changes in water distribution and mobility in the process of freezing-thawing cycles were characterized by 1H low-field nuclear magnetic resonance （LF-NMR） and meanwhile, eating quality indexes such as color, pH and water-holding capacity （WHC） were determined. NMR T2 relaxation data indicated that three distinct water populations T2b, T21 and T22 were observed in chicken muscle, which represent three states of water such as bound water, immobilized water and bulk water, respectively. T21 changed significantly with freezing-thawing frequency （P 〈 0.05）, which showed the same tendency as WHC. The deterioration of eating quality during freezing-thawing cycles was observed so that it should be avoided as much as possible. Therefore, LF-NMR can be used to evaluate the quality of frozen meat in the circulation.