Mathematical Modelling of Potassium Meta-Bisulphite Treated Mango (Mangifera indica) Slices cv Dasheri

Abstract

Fresh and ripe mango (Mangifera indica) slices cv Dasheri were dehydrated in a cabinet dryer at drying air temperatures of 50, 60, and 70 oC at a slice thickness of 5 mm. Before dehydration, the mango slices were pre-treated with potassium meta-bisulphite (KMS) at three levels (0.5 %, 1.0 %, and 1.5 % KMS, respectively). Five semi-theoretical and empirical thin-layer drying models (Newton [Lewis], Logarithmic, Demir et al. 2004, Henderson & Pabis, and Wang & Singh) were employed to select the best model that describes the drying process. Moisture diffusivity and activation energy of the mango slices were also evaluated. It was observed that the drying took place in the falling rate period. Demir et al. 2004 and Logarithmic models were found to satisfactorily describe the drying process of the mango slices using R², x², SSE, and RMSE as the criteria for selecting the best model. The mango slices' moisture diffusivity and activation energy range from 6.79 to 10.02×10-8 m2/s and 10.03 to 14.73 kJ/mol. Thus, KMS pre-treatment can minimise the mango slices' drying duration and drying cost.