Drying kinetics and model evaluation of banana puree during foam mat drying

Abstract

Foam mat drying is effective for dehydrating food products with inherently high sugar content, such as bananas, which are otherwise challenging to dry using conventional methods. The application of foam mat drying to two banana cultivars (Mysore and Gros Michel) was investigated. The study further assessed the drying rate and Effective moisture diffusivity (Deff) of the bananas during foam mat drying. The study also evaluated the drying behaviour of the bananas during foam mat drying using seven mathematical models. The drying of banana foam was carried out using an air-oven dryer at 50 oC, 60 oC and 70 oC. The results from both varieties revealed that the drying curves exhibited steep slopes toward equilibrium, indicating efficient and rapid moisture removal. However, the rate of drying was faster in Gros Michel than Mysore owing to the lowest foam density (0.27 g/cm3) exhibited by Gros Michel compared to Mysore (0.30 g/cm3). Effective moisture diffusivity (Deff) increased with drying temperature across both varieties. Among the models that were fitted, the Modified Henderson and Perry model, Three-parameter model, and Newton model provided the best fit to the experimental data in both Mysore and Gros Michel.