Application of mathematical techniques to study the moisture loss kinetics and polyphenol degradation kinetics of mango (Mangifera indica L.) slices during heat pump drying by pilot equipment

Abstract

In this study, mathematical technique was applied to evaluate the moisture loss and polyphenol compound degradation during the heat pump drying of mango slices. The experiment was carried out in two steps. First, the samples were dried at 20, 30, 40 and 50 °C; the data was subsequently inserted into the regression equations to evaluate the kinetics of the process. The results showed that selected Weibull model was the most suitable for describing mango slices' moisture loss during the drying process with the highest R2; the lowest χ2 and constant drying rate (k) varied from 7.91 to 4.07 min−1 in the temperature range of 20–50 °C. In addition, the Deff coefficients and the activation energy required for the moisture loss process were also calculated. During the drying process, polyphenols were considered an indicator of the quality of dried mango slices. The degradation of polyphenols was described according to first-order kinetics with R2 peaking at 0.9662. The nature of the drying, general methods for modeling the drying mechanism, and optimization of the processes were also discussed, providing insight into the overall drying process in terms of quantity and quality.