Journal of Microwave Power and Electromagnetic Energy (JMPEE)
TITLE	Dielectric Food Data for Microwave Sterilization Processing [PDF]
AUTHORS	Th. Ohlsson and N.E. Bengtsson 1975 10 1 93-108
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Abstract Using a cavity perturbation method we have extended our earlier measurements on the dependence of dielectric food data on temperature at the microwave frequencies of 2800, 900 and 450 MHz to temperatures from + 60ºC up to +140°C for a number of food products. Such high temperature data are required for microwave sterilization studies. The results obtained are in good agreement with previously reported data at the temperatures where such data are available. At temperatures above +60°C, ε', decreases gently with temperature, whereas ε", clearly increases, particularly at lower frequencies and for salty foods. Penetration depths calculated from the data show a clear advantage for the two lower frequencies only at temperatures below about 50°C. Application of the new data to computer simulations of microwave sterilization show that the resulting temperature depends to a large extent on the food composition as well as on the frequency.