DRYING KINETICS OF THE SLICED PULP OF BIOFORTIFIED SWEET POTATO (Ipomoea batatas L.)

ABSTRACT Biofortified sweet potato (Ipomoea batatas) is one of the foods with the highest contributions of carotenoids in the diet, especially provitamin A carotenoids. Thus, this study aimed to analyze the drying kinetics of the biofortified sweet potato pulp using the Akaike (AIC) and Schwarz's Bayesian (BIC) information criteria for model selection, as well as determine the effective diffusion coefficient and activation energy under different drying conditions. The biofortified sweet potatoes were sliced into chips and submitted to drying in an air circulation oven at 1.0 m s−1 at temperatures of 45, 55, 65, and 75 °C until constant mass. The mathematical models Wang and Singh, Verma, Thompson, Page, Newton, Midilli et al., logarithmic, Henderson and Pabis, two-term exponential, two-term, diffusion approach, frequently used to predict the drying of vegetal products, were adjusted to the data. The Wang and Singh model was selected to represent the drying of the biofortified sweet potato pulp by exhibiting the best adjustment for most conditions. The AIC and BIC criteria were suitable for selecting the Wang and Singh model. The effective diffusion coefficient increased as drying air temperature increase and the activation energy for liquid diffusion was 29.18 kJ mol−1.