5. Microwave drying applied in the food industry
Microwave drying is not common in the food industry. There are many reasons for its limited
use: the technical problems described above were not well- understood in the past. This has led
to some failures, which have surely discouraged other potential users. Schiffmann (2001) has
listed a number of formerly successful applications that have been discontinued. Among these
are the finish drying of potato chips, pasta drying, snack drying, and the finish drying of
biscuits and crackers. It is apparently not always the microwave process itself but rather
changes in the circumstances of production that make competing technologies more successful.
In spite of these difficulties, there are some current applications. Schiffmann (2001) mentions
cereal cooking and drying with a production rate of nearly 1 ton/h. Pasta drying with
microwaves is carried out in Italy. Microwave- vacuum drying is being used for meat
extract and, at least for a number of years, for the production of a powder made from orange
juice concentrate.