Freeze-dried product and process and apparatus for producing it

Abstract

Freeze-dried products of high quality produced from materials to be freeze-dried in a freeze-drying apparatus comprising a sealed vessel enclosing a processing chamber provided therein with a rotary cage receiving a gas-permeable container containing frozen pieces of the said material, prepared by freezing the said material with a refrigerant, and a heating device for heating the frozen material by radiant heat rays, wherein the freeze-dried product is produced by a process which can attain, even when dry ice is used as the refrigerant, efficient sublimating removal of large amount of carbon dioxide gas evolved from dry ice and of moisture included in the material, while preventing adhesion of the frozen pieces of the said material to each other and while permitting reduction of the sublimation duration, wherein the frozen material retained in the gas-permeable container placed in the rotary cage is heated uniformly by the heating device under vacuum condition while it is being maintained under rotational movement to thereby facilitate the volatilized removal of the refrigerant and of the frozen moisture from the frozen material.

Dependencies are inferred from the claim text.