STRUCTURAL ASPECTS OF RAMBUTAN (NEPHELIUM-LAPPACEUM) FRUITS AND THEIR RELATION TO POSTHARVEST BROWNING

Rambutans rapidly lose their attractive appearance after harvest because of a superficial browning of the pericarp. The structure of the pericarp of rambutan fruit was studied with specific emphasis on the spinterns before and during the browning process. The spinterns contained many vascular bundles (15-20) with both phloem and xylem vessels. Plasmolysis of the cells was apparent before the occurrence of browning. In brown tissue shrinkage of the cells was severe and cells containing black contents were shown to be dead. There were many stomata on the spintern and these appeared to be always open. These observations support the view that the superficial browning of rambutan pericarp is related to water loss. The structure of the rambutan facilitates this loss of water.