Determining Slice Thickness of Banana (Musa spp.) for Enclosed Solar Drying using Solar Cabinet Dryer under Ethiopian Condition
The present study was executed to determine optimum thickness of banana slice for enclosed solar drying and to evaluate the Natural Resource Institute (NRI)-modified local Kawanda solar cabinet dryer under Ethiopian condition. In this study, six slice thicknesses of banana and NRI-modified solar cabinet dryer were evaluated from 2006 to 2007. The percentages of sticked, mouldy, brown and shriveled slices and moisture content and percentage of acceptable slices were determined after four days of drying. The results indicated that the percentages of sticked, shriveled and brown slices decreased whereas the moisture content increased as the slice thicknesses increased. Percentage of mouldy slices was higher at 6 mm (38%) whereas no mouldy slices were observed at slice thicknesses of 1 to 4 mm and vey few (3%) mouldy slices at 5 mm. Moisture contents of less than 20% were achieved after four days of drying at all slice thicknesses except at 5 and 6 mm. Large percentages of acceptable slices were obtained at 3 and 4 mm thicknesses. From these results, banana slice thicknesses of 3 and 4 mm were selected as optimal for enclosed solar drying. The dryer was confirmed to be suitable for Ethiopian condition. However, it is expensive and not handy for small-scale households. Hence, we reduced the size of the dryer three times. Therefore, we suggest the use of NRI-modified rural Kawanda solar cabinet dryer for medium-scale drying whereas the JUCAVM-modified dryer for small-scale households using banana slice thickenesses of 3 and 4 mm. We suggest the need for further studies to investigate the physico-chemical characteristics of the dried banana product.