The present invention defines a process for vacuum drying fruit or vegetables, particularly tropical fruit, such as bananas, mangos and pineapples, so as to provide an exceptionally sweet and flavorful fruit chip snack product which is substantially free of any additives such as frying oil, preservatives, added sugar and artificial sweeteners. The process is a vacuum drying process and utilizes a drying apparatus in the form of an autoclave which contains within it a stacked platen heat exchanger wherein trays of the fruit to be dried are placed between heated platens in the heat exchanger. The platens are heated using hot water or a hot water/steam mixture and the drying is done in the autoclave under pressure.