Estudo experimental e modelagem matemática do processo de secagem da folha de batata-doce (Ipomoea batatas)

Abstract

Among the existing Non-Conventional Food Plants, sweet potato leaves stand out. Because it contains antioxidants, vitamins and minerals, its use in human food is recommended to bring health benefits. As a way to rolong its conservation and facilitate storage, the drying process can be used. However, this process must take place under specific conditions so that the product is not negatively affected. Thus, it is necessary to know the behavior of sweet potato leaves during drying, and one of the useful tools to predict the behavior of products under this process is a mathematical modeling. Thus, the objective of the present work was to carry out experiments on the drying kinetics of sweetpotato leaf under temperatures of 40, 50, 60 and 70 ° C, in order to mathematically model this process to determine which mathematical model better the represents. Furthermore, it was also aimed to obtain the effective diffusion coefficient for each temperature evaluated. After carrying out the work, it was possible to observe that the behavior of the loss of mass of this type of sheet was theoretically expected, in which a greater loss of mass was obtained at the beginning of the process. Furthermore, for the higher temperatures, drying occurred more quickly. Regarding the mathematical model adjustments, Wang and Singh's was the one that best represented the sweet potato leaf drying process, with a coefficient of determination (R²) closer to unity and lower values of reduced chi-squared (X²) and mean relative error (P). As for diffusivity, the effective diffusion coefficient values found were consistent with the literature, ranging between 0,5.10-¹¹ and 2,3.10-¹¹ m² s-¹, in the temperature range of 40-70 °C.