EXPERIMENTAL RESEARCH ON DRYING CHARACTERISTICS OF LITCHI

Abstract

The changes of inner temperature and drying characteristics of rind, membrane, flesh and stone of Litchi were investigated under constant relative humidity of drying medium at different temperatures at atmospheric and decompression conditions. Results show that the membrane resists moisture from moving the flesh or stone to rind. Decompression drying is helpful to the moisture evaporation of the fruit; when the moisture content lowers to a certain critical point, the drying rate is higher than that of atmospheric drying. Drying curves are very different from those of seeds drying or particle drying. In the drying process, temperature of Litchi whole fruit rises quickly at the beginning to a maximum region, then falls to a minimum before rising again slowly. All the phenomena are due to the composite structure of Litchi.