Freeze-Dehydration by Microwave Energy
WORCESTER POLYTECHNIC INST MA
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A general unsteady state analysis is used to derive a mathematical model of the freeze-drying process using microwave heating. The temperature and water vapor concentration profiles inside the material being dried are calculated. The model is applied to simulate the freeze-dehydration of beef meat by microwave dielectric heating at 2450 MHz. The results of the calculations show that the microwave freeze-drying process is mainly controlled by heat transfer. The study of the effects of the process constraints and variables upon the drying time andor the freeze-dryer output indicates that an optimal operation highest product yield would be for an operation near corona and overheating or melting conditions. Drying times as short as 1 12 hours should be possible, if corona is to occur beyond a peak strength of 255 Vcm.
- Food, Food Service and Nutrition