STM microtec: aroma, quality and low energy consumption with the cryogenic grinding for spices

Since 1971 STM has been providing integrated solutions and tests for grinding and dosing. A wide and complete range of customized services, from a single machine to complete packages for numerous industrial applications.
For processing spices STM successfully applies cryogenic grinding as the pulverization processes normally performed at room temperature can be carried out at cryogenic temperatures with better quality of the ground product and with a reduction in energy consumption.
STM has developed two product lines for cryogenically grinding spices: the MP and MR series mills.
With the MP series pin mill, grinding takes place by impact, without selecting the material, and the final product is characterized by homogeneous grains which have maintained a uniform crystalline lattice and contains high quantities of oil. The fineness of grinding can be adjusted from extra fine d.90 <40µm to a material with low amounts of dust.

The MR series sieve mill treats more friable products, containing fewer oils, with a sieve through-diameter that allows to obtain a finished product, without further steps and with an integrated selection.

The mills of the MP and MR series have the possibility of easily mounting interchangeable working tools, thus allowing a modularity of the system able to meet the specific needs of the customer.

STM cryogenic solutions ensure the maintenance of the organoleptic, physical and chemical properties in the finished product. The liquid nitrogen used for cooling, in fact, allows to limit the natural temperature increase by crystallizing the microelements contained in the spices, thus safeguarding aroma and quality.

Furthermore, the typical problems of traditional grinding are considerably reduced. Thanks to cryogenic grinding it is possible to make products fragile that are not in nature and, since the cooling of the material to the embrittlement temperature occurs before it enters the grinding mill, packing phenomena that would lead to plant shutdowns are avoided.

Furthermore, cryogenic ground substances have different physical characteristics from those obtained with traditional grinding processes, due to the way in which the structure of the material is broken. For example, the high relative speed of the MP series mill discs and the large grinding chamber, which prevents stratification problems, ensure as a final result powders with uniform physical characteristics.

Last but not least:

  • better production yield
  • better quality of the final product, without fraying or breaking the molecular lattice
  • reduction of processing waste, due to oxidation or overheating
  • reduction in the amount of material to be reprocessed in the grinding system.

Finally, the design of STM solutions complies with current ATEX regulations since the application of liquid nitrogen produces an inert, extremely dry and non-toxic atmosphere in the grinding plant.

STM has a Pilot Plant also equipped with an efficient Laboratory where to simulate and verify the performance of its technologies, varying the input material and the operating and process parameters, adapting the solutions to every need.