A theoretical analysis on microwave heating of food slabs attached with ceramic plates: Role of distributed microwave incidence

A detailed analysis has been carried out to study efficient heating processes due to microwaves for one dimensional food samples placed on ceramic plates with various distributions of microwave incidence. The enhanced heating effects due to microwave propagation within samples have been illustrated via average power within a sample vs sample thickness diagram. The maxima in power, also termed as 'resonances' is observed for specific sample thicknesses. The spatial temperature distributions illustrate the presence of local thermal heating effects for various cases. Either one side incidence or both sides incidence with suitable distribution of microwave incidence may be preferred for various food materials attached with ceramic plates. One side incidence may cause overall larger heating rates for beef samples and the heating rates for oil samples would remain invariant irrespective of various distributions of microwave incidence. It is observed that beef samples would exhibit greater thermal runaway specially with SiC plate in presence of both sides distributed microwave incidence whereas oil sample would exhibit smaller thermal runaway effects with both sides equi-distributed microwave incidence irrespective of any ceramic plates. Current analysis has been illustrated for low and high dielectric food materials (beef and oil) and based on our analysis, a generalized heating strategy for any materials due to uniform plane waves may be derived. © 2006 Elsevier Ltd. All rights reserved.