Estimation of dielectric properties of osmodehydrated foods by inverse numerical technique

CAMPAÑONE, L.A.; ARBALLO J.R; BAVA A.; MASCHERONI R.H

Congreso; Effost 2015; 2015

The present work deals with the estimation of dielectric properties of food materials during heatingprocess. A microwave heating system was employed to heat the samples, previously treated by osmoticdehydration. It includes a microwave power generator, from which the signal is split into two equal andcoherent wave fronts through a power splitter in waveguide and both signals are conducted through theelbows to a straight waveguide section where the testing sample can be introduced. During theexperiments central and surface temperatures were registered by optical sensors. Besides, a 3Dmathematical model was developed, by solving the energy transfer during the microwave heating process,considering dielectric properties of the product to be temperature dependent. The model solved theelectromagnetic energy distribution outside and its value inside the foods through the solution of Maxwellequations. The mathematical model was employed to simulate temperature data obtained from using theprototype equipment developed. The numerical predictions were compared with experimental values. Foreach thermal history, the standard deviations were obtained and the property values that minimized anerror function were considered as valid (inverse technique). These results were validated with experimentaldata obtained for osmodehydrated pears in our laboratory and were contrasted with correlationspresented in literature.