冰温及冷藏对鲤鱼水分迁移及质构的影响

Effects of the Ice Storage and Cold Storage on Migration of Moisture and Texture Changes of Carp

以淡水鲤鱼为研究对象,利用低场核磁共振技术(LF-NMR)研究冰温(-2℃)及冷藏(4℃)条件对鲤鱼肌肉水分迁移的影响,并对鱼肉质构特性进行分析,考察水分迁移对鱼肉质地变化的影响。结果表明:鲤鱼在-2℃与4℃贮藏时,结合水、不易流动水以及自由水含量(pT_(21),pT_(22),pT_(23),pT_(24))的变化趋势相似,-2℃下鲤鱼肌肉各水分组分含量的变化更为稳定。冰温及冷藏条件下,T_(21)和T_(22)对应的结合水变化不大,T_(23)和T_(24)对应的不易流动水和自由水迁移明显。不易流动水的结合程度均随贮藏时间的延长而下降,-2℃贮藏下鱼肌肉自由水的结合程度变化较平缓。4℃贮藏下,鱼肉质构特征参数与贮藏时间相关度高于-2℃,即4℃下贮藏鱼肉的质地特性随贮藏时间的变化更为明显。-2℃时T_(22)对应结合水的水分活度对弹性影响较大,4℃时T_(21)对应结合水的水分活度对弹性影响较大。-2℃与4℃下鲤鱼肌肉中的不易流动水与自由水含量呈显著负相关,即不易流动水向自由水的迁移均很明显。4℃贮藏下鱼肉各水分指标间的相关度普遍高于-2℃,表明4℃贮藏下鲤鱼肌肉内部水分迁移更为剧烈。

The effects of storage temperature（-2 ℃ and 4 ℃） on migration of moisture changes of carp was studied using NMR in this paper,and the texture indexes was measured at the same time.In addition,the correlation analysis was carried out on these indexes.The results showed that,the variation trend was similar among the content of combined water,immobilized water and free water（pT_（21）,pT_（22）,pT_（23）,pT_（24）） under-2 ℃ and 4 ℃,and the variation trend of migration of moisture under-2 ℃ was more stable.The combined water which represented by T_（21） and T_（22） exhibited little change during -2 ℃ and 4 ℃ storage.However,the immobilized water and free water which represented respectively by T_（23） and T_（24） migrated significantly with the extension of storage.The bonding degree of immobilized water declined with the extension of storage under the two temperatures,and the bonding degree of free water under-2 ℃ changed more gently during storage.The correlation between texture parameters and storage time which under 4 ℃ was higher than that under -2 ℃,and this indicated that the texture characteristics of fish under 4 ℃ changed more distinctly as the extension of storage.The springiness of fish was influenced more by combined water represented by T_（22） under -2 ℃,while,influenced more by T21 under 4 ℃.The content of immobilized water significantly negative correlation with free water under both -2 ℃ and 4 ℃,and this indicated that the water migration from immobilized water to free water was significant.The correlations between the various indicators of water under 4 ℃ were generally higher than that under -2 ℃,and this indicated that,the moisture migration of carp was more intense during storage at 4 ℃.