Puffing is a patented technology used for drying food
in the MIVAC-3 multi-drum vacuum dryer.
HOW DOES IT DIFFER FROM TRADITIONAL DRYING?
Drying in conventional dryers (belt, drum or chamber dryers) makes the material lose its biologically active ingredients, especially vitamins. This is because the final drying stage, when the moisture content of the material is already below 20%, is very slow (it takes even several hours) and the temperature of the dried material is high. Such conditions have a negative impact on the quality of drying.
Vacuum drying allows to obtain dried fruits and vegetables with unique properties, which are not available by conventional methods. All of this is due to the reduced pressure and energy of a properly selected power in the process chamber. In the process, which is carried out in the MIVAC-3 dryer, all the unfavorable factors affecting the quality of the obtained drought are eliminated. The drying process is very fast (usually takes 1-3 minutes), and in addition, by maintaining a low pressure in the chamber, the boiling point of the water and thus the temperature of the material during the drying process is significantly reduced.
The product created in such a process is distinguished by the characteristic effect of loosening dried pieces of fruit or vegetables – it is the so-called “puffing effect”. The resulting dried product has unique properties: biologically active ingredients are preserved and it has a porous (crunchy) structure with strong hygroscopic properties.
HOW DOES IT WORK?
The drying process in the MIVAC-3 multi-drum dryer is divided into three cycles:
PROPER PUFFING PROCESS
The material placed in the drum with reduced pressure at high-frequency Tesla generators is heated by the supplied energy. By reducing the pressure in the dielectric drum, it is possible to carry out a fast drying process under conditions of heating the refined material to relatively low temperatures (e.g. up to 40-60°C), which allows to obtain products with very good quality parameters. After a drying cycle, with appropriately selected time and power – the drum with the material is moved to a new position, outside the energy supply zone.
PRODUCT STABILIZATION STAGE
The material in a rotating drum is kept under reduced pressure. There is still a process of evaporation, which lowers the temperature of the dried product. Concentrated organic sugars harden by stabilizing the dimensions of pieces of dried material (cubes, flakes, etc.).
CLOSURE OF THE PROCESS
Pipe with the dried product is moved to a position where the drum rotation is switched off. The interior of the drum is aerated and the dried material is removed from the drum. Then a new portion of the material is introduced into the same drum.
We owe the innovation of puffing to the implementation of unique technical solutions. The described process is carried out in a dryer of unique design – with a special system driving the drums. With periodic control movement of the drums inside the metal chamber and a complex vacuum system enabling synchronous pumping out of the air from individual pipes and their aeration at appropriate moments.