Accession Number : ADA009578


Title :   Freeze-Dehydration by Microwave Energy


Descriptive Note : Final rept.


Corporate Author : WORCESTER POLYTECHNIC INST MA


Personal Author(s) : Peltre, Philippe R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a009578.pdf


Report Date : Dec 1974


Pagination or Media Count : 184


Abstract : 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 and/or 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 1/2 hours should be possible, if corona is to occur beyond a peak strength of 255 V/cm.


Descriptors :   *DEHYDRATED FOODS , *FREEZE DRIED FOODS , *MICROWAVES , DEHYDRATION , FOOD PROCESSING , HEAT TRANSFER , MATHEMATICAL MODELS , MEAT


Subject Categories : Food, Food Service and Nutrition


Distribution Statement : APPROVED FOR PUBLIC RELEASE