Abstract: Different kinetic models describing tea polyphenols (TP) released from poly-(vinyl alcohol) (PVA) films into water were investigated. The release behavior of TP was studied through release experiments. The experimental data were fitted to four kinetic models and the goodness of fit of the models was analyzed. The results showed that the percentage of released TP from PVA films decreased with increasing TP content. The Fickian model and the Fickian+ first-order kinetic model could simulate TP release well (R2 ≥ 97.27), with the latter being more effective than the former. Although the Weibull model exhibited worse goodness of fit than the above two models (R2 ≥ 85.21), it could simulate TP release well during the period from the beginning to the initial equilibrium stage (R2 ≥ 92.20). The short-term release model showed good fitness (R2 ≥ 91.32). However, its diffusion coefficient was different considerably from the value obtained by the Fickian model and the Fickian+ first-order kinetic models. Among the four kinetic models, the fitness of the Fickian + first-order kinetic model was the best closely followed by the Fickian model. The Weibull model could simulate TP release behavior well during the period from the beginning to the initial equilibrium stage. The short-term release model was not suitable for simulating and evaluating TP release behavior from PVA films during the whole release process.

Key words: poly-(vinyl alcohol), tea polyphenols, release, release kinetic, kinetic model