冷藏条件下鳙鱼阻抗特性与鲜度的关系

研究鳙鱼（Aristichthys nobilis）在冷藏（3℃）条件下鱼体阻抗特性及鱼片鲜度指标的变化。对鱼体相对阻抗变化率Q和鱼片鲜度指标（K值、w（TVB-N）、细菌总数及感官评分）进行测定,分析Q与K、w（TVB-N）、细菌总数和感官评分的相关性,建立其相关性模型。结果表明：鳙鱼鱼片在3℃贮藏至第12天感官评分为14,K值为74.1%;w（TVB-N）为16.1mg/100g;细菌总数1.30×105 CFU/g;鱼体Q降至12.7%,失去感官食用价值。Q与K、w（TVB-N）、细菌总数和感官评分的相关性系数r分别为0.993、0.971、0.977和0.981,达极显著水平,表明Q与各鲜度指标具有良好的相关性,在3℃贮藏条件下采用Q快速、无损伤地评估鳙鱼鱼片鲜度是可行的。

Effect of freshness of stored bighead carp (Aristichthys nobilis) on its impedance characteristics

The effect of freshness on change ratio of impedance(Q value) of bighead carp stored at temperature of 3 ℃ was investigated.The indexes of freshness,K value,total volatile basic nitrogen(w(TVB-N)) and total aerobic count,as well as sensory assessment were determined based on the investigations.The correlation models were developed via analyzing the correlation between the freshness indexes and sensory assessment.The results indicated that the sensory assessment has exceeded the acceptable limit with the score of 14 on the twelfth day,while the K value,w(TVB-N) and total aerobic count increased to 74.1%,16.1 mg/100g and 1.30×105 CFU/g,respectively,and the Q value declined to 12.7%.The correlation coefficients are 0.993,0.971,0.977 and 0.981,respectively,indicating significant linear relations(P<0.01) between the Q value and the K value,w(TVB-N),total aerobic count and sensory scores.Therefore,one can use Q value as a fast nondestructive method to estimate the freshness of bighead carp fillets under 3 ℃ storage.