The Effect of Different Pretreatments in Drying Process of Banana Using Microwave

Since banana contains high sugar content and such fruits are so sensitive to spoilage in warm weather, using microwave ovens to dry them might have positive effects on their thermal process. At this research banana slices have been prepared at 3 different thickness (3-5and 10mm) and treated by 3 pretreatment methods (T1 pretreatment: chemical blanching by sodium bisulphate solution 1%, T2 pretreatment: first blanching by boiling water and then chemical blanching by sodium bisulphate solution 1% and T3 pretreatment: first blanching by boiling water and then chemical blanching by citric and ascorbic acid mixture (1:1) solution and an untreated sample as a control sample. After preparation, the samples were dried at a microwave oven by 3 different microwave power intensities (300, 500 and 700 w) to achieve final moisture content. And finally dried samples were evaluated in terms of : quality parameters such as: color, rehydration, sugar and vitamin C content, drying rate and time. The results showed that at treated samples drying time decreased compared with control samples but drying rate didn't follow specific procedure and microwave power increased along with the drying rate increased but drying time was decreased. Also with increase of thick slices, drying rate were increased and drying time were decreased. Pretreatments had effects on color, re hydration, vitamin C and sugar content.