Abstract

A 3D COMSOL Multiphysics model has been constructed for a stationary microwave oven and used to investigate the microwave heating process of ready-to-heat baked spinach with cheese. The model has simulated the 30 s of microwave heating for 3D geometries of food packages of varying sizes. Then Polylactic acid cup-shaped packages have been produced by using a 3D printer and tested in an experiment. In order to heat 100 g of baked spinach with cheese for 60 s, the cup-shaped packages with and without a shielded aluminum foil have been placed at the center of 1300 W microwave oven. The experimental temperature profiles obtained with a thermal imaging camera have demonstrated a good correlation with the simulated results. A uniform heating has been obtained in a cup-shaped package with a diameter of 6.7 cm and a height of 5.2 cm, shielded with the aluminum foil. A temperature at the center has been above 70 °C. The temperature differences at various locations have been less than 15 °C, indicating uniform temperature distribution. It has been also found out that the cup-shaped package has provided a better temperature distribution of the baked spinach with cheese than the commercial tray packaging. These findings may be implemented in the ready-to-heat food product development, by modifying the microwave cooking conditions in order to achieve a better heating uniformity, and the shape of microwavable packaging to maximize the cooking performance with the least amount of experimental expense and time.