EFFECT OF TEMPERATURE ON THE DRYING BEHAVIOUR OF PEARS AND APRICOTS

摘要

Convective air drying of fruit is an energy intensive process. The use of heatrnpump driers can lead to a considerable reduction in energy consumption asrnwell as the possibility of drying at lower temperatures. However, little isrnknown regarding the drying behaviour of fruit at relatively low temperatures.rnPeeled pear quarters were dehydrated at dry bulb temperatures (d.b.) of 40°C,rn45°C as well as under simulated counter-flow drying. Drying at 40° and 45°Crnrequired extended dehydration periods. Apricots (peeled and halved) wererndehydrated at dry bulb temperatures of 45°C and 60°C , and under simulatedrncounter-flow and parallel-flow conditions. Lower temperatures tended tornincrease drying times. In the case of apricot halves isothermal drying at 45°Crnin comparison to 60°C as well as drying under simulated counter-flow andrnparallel-flow conditions showed no improvement in color retention (CIE Lrnvalues) immediately after dehydration and subsequent storage.