Use of Linear and Weibull Functions to Model Ascorbic Acid Degradation in Chinese Winter Jujube during Postharvest Storage in Light and Dark Conditions

Abstract

Degradation of ascorbic acid (AA) in Zhanhua winter jujube stored at selected temperatures under continuous light and darkness conditions was described by first-order kinetics and Weibull distribution function, and the temperature dependence of AA loss was studied by the Arrhenius equation. The high correlation coefficients (R 2 > 0.99) indicated the acceptability of Weibull model for predicting the degradation of AA. Activation energy was determined to be 10.586 and 11.868 kcal/mol under continuous light condition and 12.636 and 13.190 kcal/ mol under continuous darkness condition according to first-order and Weibull models, respectively. This study revealed that the loss of AA in continuous darkness was more temperature-dependent than the other samples. In continuous light, AA degradation may be favored even if at low temperatures. Therefore, a low temperature and continuous darkness condition is recommended to preserve AA content in jujube fruits during postharvest storage.