Microwave appliance performance as affected by container geometry and material

Effects of container geometry and material on microwave cooking performance, as measured by evenness of cooking, firmness, and moisture content were compared. Three food items were heated in round, tube, loaf, and square containers made of clear glass, amber glass, thermoset polyester, and polysulfone. Unflavored gelatin, custard, and cakes were prepared three times in each of the 13 microwave containers. Evenness of cooking was determined by comparing meltdown and temperature in gelatin, temperature and separation/uncooked portions in custard, and index to volume in cakes. Firmness was measured in custard while moisture content was determined in cakes. In analysis of the data, ANOVA and Duncan's multiple range test were performed.

Significant differences were found between shapes as food items heated more evenly in tube and round containers than in square containers. Food quality was affected more by shape than by material. Foods prepared in the, plastic materials were more evenly heated than in the glass materials.

Statistically, shape and material interacted with each other for three measures of microwave appliance performance temperatures and separation/uncooked portions of custards, and index to volume in cakes. The interaction of shape and material was greater as the heating time increased.