Comparison of temperature distribution in model food cylinders based on Maxwell's equations and Lambert's law during pulsed microwave heating

Abstract

Two-percent agar gel cylinders were heated using pulsed and continuous microwave energy. Temperature distribution inside the sample was measured and compared with numerical predictions based on the Lambert's law and Maxwell's equations. The Maxwell's equations account for the standing wave effect inside the sample, the Lambert's law does not. The results show that the predictions based on the Maxwell's equations are statistically more accurate than those based on the Lambert's law, especially around the sample edge. The measured temperature distributions and the corresponding predictions using both models indicate better temperature uniformity in the agar gel cylinders under pulsed microwave heating, though the total process time is longer, than under continuous microwave heating.