Physical-chemical characterization of yellow mombin (Spondias mombin L.) foam-mat drying at different temperatures

Abstract

The objective of this work was to perform foam-mat drying of yellow mombin pulp, verifying the kinetics and mathematical modeling of the process, and characterizing the obtained product with respect to physical and chemical characteristics, compared with the fresh pulp. Foam-mat drying was carried out with the aid of the foam agent Emustab®, at temperatures of 50, 60, 70 and 80 °C. The drying data were analyzed and fitted to four mathematical models (Wang & Singh, Verma, Page and Midilli). Effective diffusion coefficient and activation energy were determined. Titratable acidity, pH, soluble solids content and vitamin C content, as well as the solubility in water of yellow mombin powder and color variance (L*, a*, b*) were analyzed in both fresh and dehydrated pulp. The Wang & Singh model showed best fit at the temperature of 50 °C, whereas the Midilli model showed the best mathematical fit at temperatures of 60, 70 and 80 °C. Net diffusion coefficient and activation energy values were proportional to the drying temperature. Drying of the foam at 60 °C indicated guarantee of quality of yellow mombin pulp with respect to titratable acidity, pH and color of the a* coordinate.