Abstract:
The effects of different pre-treatments and temperature on the drying characteristics of ripe Gros Michel banana
slices were investigated. 5- and 7-mm thick slices of bananas were pre-treated with four different pre-treatments such as
ascorbic acid, lemon juice, salt solution, honey dip and a control for 10 minutes, each replicated three times. Pre-treated
banana slices were dried in a cabinet oven dryer using a completely randomized design at 60°C and 70oC and their drying
characteristics such as rate of drying, moisture diffusivity, re-hydration ratio, and coefficient of re-hydration were studied.
The moisture content of the fresh ripe bananas for both the untreated and treated samples was found to be in the range of
75-77 % (w b) which reduced to 16.8 to 27% after oven drying for various thicknesses and temperatures of air drying for
16 hours. The moisture diffusivity during oven drying varied from 7.89E-5 to 14.94E-5 m/s2, and increased with drying air
temperature. The 5 mm thick slices at a drying air temperature of 70°C dried better than the others and resulted in about
13% savings in time. The minimum re-hydration ratio of 1.215 was obtained for 7 mm thick slices treated with ascorbic
acid and the maximum re-hydration ratio of 1.716 was obtained for lemon juice samples. This means that the lemon juice
treated dried bananas will reconstitute more moisture when exposed to air
