Fricke and Mallah has acquired a recognized expertise in microwave freeze-drying. This is also called lyophilization or sublimation drying. Shorter drying times for thermally sensitive products such as food or pharmaceutical products require the use of microwave technology under vacuum atmosphere. In this process, the ice crystals sublimate directly into the gaseous state without any intermediate liquid phase.
The demand for microwave freeze-drying in industrial drying systems has continuously increased in the last years due to the high energy efficiency and the performance potential. Consumers have developed a new awareness for healthy ingredients such as flavors, antioxidants and vitamins in food. In addition, microwave freeze-drying has significant advantages, as they are faster, smaller and more efficient than conventional systems.
For freeze-drying we have developed a new, highly innovative process based on solid state microwave technology without arcing under typical vacuum atmosphere conditions. In contrast to magnetron generators, these generate a uniform, reproducible and homogeneous field distribution. This eliminates the main cause of uneven heating and allows the advantages of volumetric energy input by microwaves to be used, although other factors such as the shape, composition of inhomogeneous food or packaging can lead to so-called hot or cold spots.
The process using Solid State microwave technology, unlike magnetron generators, produces a uniform, reproducible and homogeneous field distribution. This eliminates the main cause of non-uniform heating and allows the advantages of volumetric energy input by the microwaves to be exploited, even though other factors such as the shape, the composition of inhomogeneous foods or the packaging can lead to so-called hot or cold spots. This results in much faster and also considerably gentler results.
In addition, the Solid State generators can be adjusted more flexibly to the product. A major problem with conventional microwave freeze-drying systems is the fixed frequency specified by the magnetron. With Solid State generators, frequency changes with power adjustment are no problem and ensure stable processes.
Microwave-based heating and drying of food is put on a fundamentally new basis by using innovative, semiconductor-based solid-state microwave generators.