OPTIMAL MODES OF OPERATION FOR MICROWAVE FREEZE DRYING OF FOOD

Abstract

ABSTRACT In freeze‐drying, the quality of the resulting product often determines the attractiveness of the drying process. Therefore, the temperature profiles within the material are as important as the total drying time required. For microwave assisted freeze drying, it has been indicated both experimentally and in theoretical analysis that the maximum applicable constant field strength for beef cubes is 130 v/cm. Beyond this point melting of the ice core and/or overheating in the dried layer will occur. However, the drying time can be further reduced by 20% if a simple preprogrammed stepwise adjustment of the applied field strength is introduced.