Other drying techniques evolved due to the need to produce high-quality dried products that are ultraheat sensitive. Such drying
systems include, for example, the utilization of temperatures below the freezing point and at vacuum pressure conditions (e.g.,
freeze drying) (Figure 6). Freeze drying (also known as lyophilization) is a drying process in which the food is first frozen, then
dried by direct sublimation (i.e., phase changes from solid to vapor) of the ice under reduced pressure (Oetjen and Haseley,