花生仁与核桃仁贮藏货架期预测模型

Predictive Modeling of Shelf Life of Peanut and Walnut Kernels during Storage

采用加速贮藏试验,研究花生仁与核桃仁贮藏中脂肪氧化的动力学及其货架期预测模型。花生仁和核桃仁分别采用真空和露空两种贮藏方式贮藏于0～50℃。以过氧化值(POV)为指标,通过对不同温度下POV的测定,建立了POV与贮藏时间(t)的一级反应动力学方程以及反应速率(k)与贮藏温度(T)的Arrhenius方程;低温和真空贮藏时,氧化反应的活化能(EA)明显升高,证明低温和真空条件可延缓果仁的氧化酸败;两种贮藏方式下,核桃仁反应活化能(EA)均小于花生仁EA,表明核桃仁氧化稳定性低于花生仁。两种果仁的一级化学反应动力学模型和Arrhenius方程均具有较高的拟合精度(R2>0.95),建立的模型对货架期的预测值与实测值接近(RE<10%),表明论文得到的预测模型可快速准确的预测0～50℃条件下花生仁与核桃仁贮藏的货架期。

In this study, accelerated storage tests were used to explore the kinetics of lipid oxidation in peanut and walnut kernels and develop mathematical models for predicting their shelf lives. Peanut and walnut kernels were stored at 0-50 ℃ in a vacuum or atmospheric environment to measure the changes of peroxide value （POV） at 20 d intervals during storage at different temperatures （0, 20, 30, 40 ℃ and 50 ℃）. A first-order reaction model between logarithmic POV and storage time （t） was fitted and an Arrhenius model of reaction rate constant （k） with respect to storage temperature （73 was established for peanut and walnut kernels, respectively. The oxidative rancidity of both kernels could be inhibited in vacuum or at lower temperature due to the increased EA; walnut kernels were more sensitive to oxidation due to having lower EA than peanut kernels. The observed high regression coefficients （R2 〉 0.95） and similarity between the experimental and predicted shelf lives of peanut and walnut kernels indicated the high reliability of the established first order reaction model and Arrhenius model for the prediction of shelf life during storage at 0 - 50℃.