Freeze-drying coffee extract to form pellets, by foaming extract, dropping foam onto cooled belt as pellets

摘要

Freeze - drying of coffee extract involves:(a) foaming coffee extract with 35-45 wt./vol. % dry matter, to a foam wt. of 450-750 g/l; (b) dropping the foamed extract onto a cooled belt, to form pellets and freezing the pellets on the band at below -30 deg C; and (c) drying the frozen pellets under a pressure 2-4 x that used in the normal freeze-drying of ground coffee granulate.