减压处理鲜切西兰花的货架期预测模型构建

Establishment of Shelf-life Prediction Model of Fresh-cut Broccoli with Hypobaric Treatment

将鲜切西兰花减压处理36 h后,分别置于273 K、278 K、283 K、288 K、293 K五个不同温度下贮藏,定期检测Vc含量的变化。应用化学反应动力学的零级反应和一级反应两种模型分别对Vc的变化趋势进行拟合,确定了不同温度下Vc的变化速率k,结果表明:Vc变化速率k随温度的上升而增大,以一级反应为模型的拟合方程优于以零级反应为模型的拟合方程。应用Arrhenius方程,进一步确定了温度与Vc变化速率k之间的关系式,由此构建了2种货架期预测模型。最后结合感官评价对2种货架期模型进行准确性评估,发现:基于一级反应建立的货架预测模型SL1的准确度较高,平均相对误差为7.94%,R2=0.9986,模型参数为:指前因子k0=-3.19×1020,活化能Ea=118762.49。此模型SL1可有效估测273 K到293 K范围内任意温度下,减压处理鲜切西兰花的货架期。

The Vc content of fresh-cut broccoli was determined during storage ,while the fresh-cut broccolis with hypobaric treatment for 36 h were placed at 273 K, 278 K, 283 K, 288 K and 293 K, respectively. The trend of Vc was fitted using zero order reaction and first order reaction based on chemical reaction kinetics theory to determine the variation rate ofVc （k）. Two shelf-life prediction models were established combined with Arrhenins equation and the accuracy of models was evaluated combined with sensory evaluation. The results indicate that the content of Vc decreased with increasing storage time and temperature, and the variation rate of Vc （k） increased with increasing temperature. Accuracy evaluation between predicted and observed sbelf-life showed that the predictive accuracy of shelf-life prediction model SL1 based on first order reaction （preexponential factor： k0=-3.19×10_20, activation energy： Ea=118762.49, R2=0.9986） was the highest with the average relative error being of 7.94%. The shelf-life of fresh-cut broccoli with hypobaric treatment can be predicted at the storage temperature from 273 K to 293 IC