基于质构变化的罗非鱼片冻藏保质期预测

Prediction of the Shelf-Life of Frozen Tilapia Based on Changes in Texture Parameters

探究预测罗非鱼保质期的新方法,测定真空包装罗非鱼片的质构参数、pH值、电导率、水分活度和挥发性盐基氮含量在-5、-20℃和-40℃贮藏条件下随时间延长的变化趋势;求取各质构参数变化和品质参数变化的Pearson相关性,并以其为依据,选取内聚性和弹性作为指示真空包装冻罗非鱼片品质变化及保质期终点的指标;得出当内聚性0.20、弹性0.65时为鱼片保质期的终点;分别建立内聚性和弹性变化与贮藏时间的一级动力学方程,求取其变化速率常数与贮藏温度间的Arrhenius方程。实验求得基于内聚性一级动力学方程的反应活化能Ea=53.532 kJ/mol,指前因子k0=215.64;基于弹性活化能Ea=89.866 kJ/mol,指前因子k0=1 620.68,根据上述研究参数分别预测冻罗非鱼片保质期,其结果与实测值的误差均在可接受范围内。结果证实:冻罗非鱼片内聚性和弹性均可以作为预测冻罗非鱼片保质期的参数依据。

The purpose of this research was to explore a new method to predict the shelf-life of tilapia. This study investigated the quality of vacuum-packed tilapia fillets by monitoring the changes in texture, pH, conductivity, aw and total volatile basic nitrogen （TVB-N） value when stored at -5, -20 and -40 ℃ for different periods of time, respectively. The Pearson correlations between the changes in texture parameters and those in quality parameters were analyzed. According to the results, cohesiveness and springiness were selected as the optimal indicators of the quality changes and shelf-life for frozen vacuum-packed tilapia fillets. The present research showed that cohesiveness up to 0.20 or springiness up to 0.65 was the end of fish shelf-life; the first order kinetics equations between either cohesiveness or springiness and storage time was established as well as the Arrhenius kinetics equations describing the rate constants for the changes in both texture parameters as a function of storage temperature. The reaction activation energy Ea was 53.532 kJ/mol, and the pre-exponential factor k0 was 215.64 based on cohesiveness; the Ea was 89.866 kJ/mol, and the pre-exponential factor k0 was 1 620.68 based on springiness. From experimental results, the shelf-life of tilapia fillets stored at different temperatures was estimated and the measured values were in the acceptable range as compared with the real values. Therefore, the cohesiveness and springiness of frozen tilapia fillets could he used to predict their shelf-life.