Gerald J. Silverman

The Microbiology of Freeze-Dried Foods

Publisher Summary In this chapter, the microbiology of freeze-dried foods is discussed in detail. The refrigeration of freeze-dried foods is unnecessary; rehydration is rapid; shrinkage is minimal; chemical activity is appreciably deterred (especially if stored at 20°C. or lower); since most of the water is removed a considerable savings in weight is achieved; and, if properly processed and packaged, microbial multiplication is virtually eliminated during storage. At the present time, these advantages must be balanced against the additional increment of cost incurred by this process and a loss in certain quality characteristics. It can be expected that both of these factors will receive greater attention from the food industry, and, as product improvement is achieved and cost lowered, the application of freeze-drying as a technique for food preservation will be increased. Although one cannot presume that freeze-drying will be a major method of food preservation, the volume of freeze-dried foods should be appreciable and the microbiological aspects of freeze-dried foods must be properly evaluated so that standards might be promulgated.