Drying kinetics of ‘gueroba’ (Syagrus oleracea) fruit pulp ¹

Cinética de secagem da polpa dos frutos de gueroba (Syagrus oleracea)

ABSTRACT

The ‘Gueroba’ fruit can be used to produce flours with potential for the development of new products from the ‘Cerrado’ socio-biodiversity. The objective was to estimate the drying kinetics and determine the effective diffusion coefficient and activation energy for the pulp of ‘gueroba’ fruits subjected to different drying temperatures. ‘Gueroba’ fruits were manually pulped, removing the mesocarp with the epicarp, and this material was identified as the pulp. The material was subjected to oven drying at temperatures of 40, 50, 60 and 70 °C. Nonlinear regression models were fitted to the experimental data. The most adequate model was selected through the coefficient of determination, mean relative and estimated errors, Chi-square test, AIC and BIC. As the drying temperature increases, the processing time to achieve the same moisture content decreases, due to the increase in water diffusivity inside the product. The Midilli model showed the best fit to the experimental data obtained. The effective diffusion coefficients of the pulp of ‘gueroba’ fruits showed magnitudes between 3.11 x 10^-9 to 5.84 x 10^-9 m² s^-1 for temperatures from 40 to 70 °C. The activation energy of the process was 18.34 kJ mol^-1.

Key words:
mathematical modeling; AIC; BIC; Midilli