Heat and Mass Transfer, and Volume Variations in Banana Slices during Convective Hot Air Drying: An Experimental Analysis

Abstract

Bananas are some of the most consumed fruits throughout the world, providing metabolizable calories and vitamins for humans, along with many other benefits. However, this fruit tends to be easily degraded by microorganisms and other chemical agents because of the high moisture content. Considering the importance, this work focuses on an experimental study regarding banana fruit drying. For such purpose, whole bananas were hand-peeled and sliced longitudinally and then dried by a hot air circulation oven with air temperatures of 40 °C, 50 °C, 60 °C and 70 °C. Measurements of mass, temperature, and dimensions of the sample were done during the drying process. Results of drying, heating, and shrinkage (volume and surface area) kinetics are presented and analyzed. The study revealed that the drying air temperature significantly affected moisture removal, heating, and dimensions’ variation rates, as well as quality of banana fruit. The drying carried out with higher temperature and lower relative humidity of the air gave rise to higher rates of drying, heating and variation of dimensions, and shorter drying time of the product.