A Microwave Applicator for Drying Food Samples

AbstractA compact system using a cylindrical microwave applicator for drying disc-shaped food samples is presented. The 2450 MHz applicator is designed to operate near TM011 resonance when drying begins, creating a ring-shaped heating distribution. As the sample dries out, the TM011 resonance diminishes and a TM011 field excitation takes over, drying the central parts of the sample. The initial power transfer exceeds 60%, but decreases to about 10% when the sample is dried. For most meat products, an input power of 200W is sufficient to dry a 10-g sample in 6 to 8 min.