Experiment and Research on Lychee Drying Under Atmosphere and Decompression

The changes of inner temperature and drying characteristics for rind, flesh and stone of lychee were investigated under constant relative humidity of drying medium at different temperatures, and at atmosphere and decompression. Results show that the membrane resists moisture moving from the flesh or stone to rind. Decompression drying is helpful to the diffusion of the moisture inside the rind, but it is not so efficient to move the moisture out from the flesh or the stone. In the drying process, the inner temperature rising of lychee is slow. A proposal on appropriate drying technique for lychee is given based on the experiments.