Mikrowellen-Vakuum-Konvektionstrocknung von Lebensmitteln

At the Fraunhofer-Institute for Food Technology and Packaging a new, combined drying process for a gentle dehydration of particulate foodstuffs was developed and a pilot dryer was designed and installed. The main feature of Microwave-Vacuum-Convection-Drying is a combined energy transfer by means of microwaves and a conditioned, circulated drying agent. The operation pressure ranges from 100 mbar to 400 mbar. The results of the drying experiments performed with meat balls and valerian show, that the Microwave-Vacuum-Convection-Drying is suitable to produce dried products with a quality equal or even superior to the quality of products dried by conventional drying processes like convective drying or freeze drying. The relation of microwave energy to convective heat transfer has to be thoroughly examined for the further development of the new drying process. Thus the energy consumption can be optimized and an economic use of the process be secured. The Fraunhofer-Gesellschaft has applied for a patent this new drying method (DE P 40 36 112.8 - 16)