Kinetics of conductive hydro-drying of pumpkin (Cucurbita moschata) pulp

Abstract

Pumpkin (Cucurbita moschata) samples were dehydrated by conductive hydro-drying (CHD) (1 atm, 80 °C), sliced and purées, both structures with thicknesses of 1.5, 3 and 6 mm. Drying kinetics were analyzed and the effective diffusivity (Def) was determined in both structures at the three thicknesses. Drying curves were fitted to ten kinetic models: Lewis, Henderson & Pabis, Logarithmic, Page, Wang & Singh, Page Modified, Midilli, Diffusion Approximation, Two-term Exponential and Verma. Def was determined by analytical solution of Fick's Second Law in rectangular coordinates by Crank's method. In general, the semi-empirical model that best fit showed was Midilli's model. However, the importance of phenomenological models such as the analytical solution of Fick's second law for process scaling and equipment design should be considered. These modeling results aid in predicting performance and fine-tuning hydrodrying processes for sustainable, high-quality food. Future applications may involve integrating these models into industrial-scale hydrodryers, reducing energy consumption and environmental impact.

Keywords

• Conductive hydro-drying
• Pumpkin
• Cucurbita
• Kinetics modelling
• Effective diffusivity