Process for drying foods under reduced pressure

Abstract

A process for drying a food under a reduced pressure is provided for the preparation of a dried food which may be rehydrated to the original condition in a very short time to have pleasant taste and texture substantially comparable to an untreated food. The process is characterized by the step of placing the food to be dried in an environment of reduced pressure low enough to vaporize a portion of the water contained in the food and to freeze the balance of water by the radiation of heat by the vaporization, and the step of heating to dry the food at relatively low temperature under the reduced pressure. A further characteristic feature of the process of the invention is the sudden or abrupt drop of the pressure surrounding the food at the initial stage, whereby the food is puffed somewhat by the action of the vigorously vaporizing water to a dried state with a substantially hollow core portion and a denser surface layer.