Effects of temperature on both drying kinetics and color of Italian tomato

Abstract

This study evaluated the influence of temperature on drying kinetics and color of Italian tomato of sliced and cut into quarters using different dehydration strategies based on laboratory-convective dried and convective oven drier. The mathematical modeling of drying curves and the effective diffusivity were evaluated. It was verified that tomatoes dried in the laboratory-scale drier presented lower drying time. In addition, the drying time of sliced tomatoes were lower than the cut ones. The proposed drying model presented a satisfactory fitting of the experimental data, showing that the use of global kinetic models presents an alternative to predict the drying profiles at different temperature. It was verified that Deff for tomatoes dried in convective laboratory-scale drier were higher than for oven convective drier, in both cuts. The drying time has strong influence in darkening of the sample and it was verified a tendency in increase the redsaturation index with the temperature. The best product quality was obtained using convective laboratory-scale drier at lower drying times. The tomato cut in four parts showed characteristics of final product similar to those sliced tomatoes. However, the slices tomato dried at temperature of 60 °C showed less drying time.