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为研究河豚鱼在冻藏过程中的品质变化,通过不同温度下的冻藏试验对河豚鱼品质变化的动力学模型进行探讨。将河豚鱼冻藏在263、255、248和243K条件下,测定河豚鱼的挥发性盐基氮、盐溶性蛋白及巯基等品质指标随贮藏时间的变化。在Arrhenius动力学方程基础之上,建立了挥发性盐基氮、盐溶性蛋白及巯基的质量分数与冻藏时间及冻藏温度之间的动力学模型。结果表明:一级化学反应动力学模型和Arrhenius方程对挥发性盐基氮和盐溶性蛋白的质量分数及巯基的质量摩尔浓度的变化具有较高的拟合精度。挥发性盐基氮质量分数变化预测模型中的活化能EA及速率常数k0分别为10.72kJ/mol和0.556 0,盐溶性蛋白质量分数变化的EA及k0分别为:26.79kJ/mol和2 668.20,巯基质量摩尔浓度变化的EA及k0分别为:20.68kJ/mol和186.52。挥发性盐基氮随着贮藏时间的延长而增加,且随着贮藏温度的升高而增加迅速,其盐溶性蛋白及巯基含量指标随着贮藏时间的延长而下降,且随着贮藏温度的升高而下降迅速。
In order to study the quality changes of puffer fish in the process of frozen storage, the dynamic model of puffer fish quality was discussed through the frozen storage tests at different temperatures. The puffer fish were frozen at 263, 255, 248 and 243K, and the quality indexes of puffer fish such as volatile basic nitrogen, salt-soluble protein and mercapto were determined with the change of storage time. Based on the Arrhenius kinetic equation, kinetic models for the determination of volatile basic nitrogen, salt-soluble protein and sulfhydryl mass fraction, freezing time and freezing temperature were established. The results show that the first-order kinetic model and the Arrhenius equation have high fitting accuracy to the change of the mass fraction of volatile basic nitrogen and salt-soluble protein and the molar concentration of sulfhydryl. The activation energy EA and the rate constant k0 in the predictive model of volatile basic nitrogen change were 10.72 kJ / mol and 0.556 0, respectively. The EA and k0 were 26.79 kJ / mol and 2668.20, respectively, The changes in the molar concentrations of mercaptans were: EA and k0 of 20.68 kJ / mol and 186.52, respectively. Volatile base nitrogen increased with the storage time and increased rapidly with the increase of storage temperature. The content of salt-soluble protein and sulfhydryl group decreased with the storage time, and with the increase of storage temperature High and quickly dropped.