3 - Freeze drying for food powder production

Abstract

Powder production from wet foods involves drying and comminution processes. Among the different drying methods that could be applied to produce a dehydrated food, freeze drying has been always recognized as the best drying process for preserving the quality of foods. On the other hand, it is an expensive operation in terms of running costs and energy consumption. In this chapter, the basis for the freeze drying process in relation to food powder production will be analyzed. A description of the process introducing important variables will be included, freeze drying scaling-up issues will be described, large-scale freeze drying techniques and technological challenges will be briefly discussed and the updated application of freeze drying processes for food powder production will be reviewed in particular.