Drying Temperature

Quality attributes such as moisture content, colour parameters and shrinkage of apples change undesirably during the drying process. Drying is a highly dynamic process, thus, an effective optimisation in terms of product quality and process performance requires continuous non-invasive measurement of the parameters in question.
This study investigated the drying behaviour of purple-speckled Cocoyam and the effect of drying temperature (40 °C, 60 °C and 75 °C), slice thickness (4 mm, 7 mm and 10 mm) and pre-treatments (blanching in boiling water for 3 min, blanching in boiling water for 3 min followed by dipping in 0.1 per cent sodium metabisulfite for 5 min) and non-pre-treated slices. The process and quality criteria under consideration included the total drying time, rehydration ratio, colour difference, browning index and specific energy consumption.