Development of a Model Food for Microwave Processing and the Prediction of its Physical Properties

Abstract

Although microwave processes in the food industry such as microwave pasteurisation or microwave drying are already in use, most of their optimisation is still based on trial-and-error. To model these processes, knowledge of different physical properties of the food material is indispensable. In order to guarantee constant product properties a model food was developed imitating real food properties and showing physical and microbial stability over several months. In this manuscript the prediction of these physical properties and the comparison of the model food with a real food will be shown.

Simultaneous microwave heating and three-dimensional MRI temperature mapping

“…7, Knoerzer, Regier, Erle, & Schubert, 2004) were heated in a microwave oven (Panasonic Pro II NE 2740; continuous power supply) with varying heating time and microwave power. The samples were inserted into the tomograph for measuring phase distributions both before and after microwave heating.…”

A computational model for calculating temperature distributions in microwave food applications

“…Samples used were predominantly simple shapes (cylinders, spheres) of a model food with known temperature dependent thermo-physical properties (Knoerzer, Regier, Erle, & Schubert, 2004). However, a method was developed to allow the introduction of models of real food structures based on a 3D spindensity measurement technique (Knoerzer, 2006) as shown in Fig.…”

“…The thermo-physical properties, loss factor ε″, permittivity ε′, thermal conductivity λ, density ρ, heat capacity C P and their variation with water content and temperature were determined experimentally for a model food, developed for microwave heating research, and fitted with third order polynomials (Knoerzer et al, 2004). These equations were implemented in the subdomain settings of the software packages used.…”

Microwave Heating: A New Approach of Simulation and Validation

“…As a result, the precession frequency decreases, and thus the phase (spin angle) of the processed signal (Df/DT = 0.01 ppm/°C, [6]) also decreases. From a measured phase difference between a sample with known initial temperature and the heated sample, the actual temperature distribution can be calculated [7] (see Fig. 2).…”