Preliminary treatment for drying, texturing and debacterization of plant materials.
A new technology for the treatment of biological materials has recently been developed:
Instant Controlled Decompression. It is a high-temperature, short-term HTST treatmentthat can be used in numerous industrial processes of drying, debacterization, texturing and extraction. Applied to the dehydration sector of piece products, it has allowed the development of an innovative treatment capable of integrating drying and texturing that stands out from the classic drying techniques for its ability to combine the high quality of finished products with extremely low energy consumption.
The DIC Controlled Instant Decompression treatment can be applied to various categories of biological products such as agricultural products, agro-food, pharmaceuticals, cosmetics, etc. It consists of two successive operations:
it is a defined pressure heat treatment that can last from a few seconds to a few tens of seconds, generally applied using water vapor but also other heating fluids operating by convection or with techniques based on ohmic conduction or irradiation with infrared or microwave.
the actual decompression is obtained through the very rapid (instantaneous) exposure of the product to a more or less high degree of vacuum; this exposure causes an instantaneous pressure and temperature drop in the product.
The decompression phase causes a phenomenon of self-evaporation (mainly of water) which may eventually cause the expansion of the treated product. This phenomenon depends on the operating conditions (e.g. initial and final pressure and temperature, conditioning times, decompression duration, etc.) but also on the intrinsic properties of the considered product (physical, rheological, thermal, thermodynamic, etc.) and its possible thermal evolutions.
The impact of this new technique is evident in two main aspects.
The total duration of any drying operation can be reduced by 50% when combined with DIC treatment.
The quality of the dehydrated product is greatly improved as the overall duration of thermal exposure is reduced.
For the application of the DIC process, a series of specific plant structures have been developed that are suitable to meet the needs of any type of organic product.
Another fundamental field of use of DIC technology is that of debacterization. Numerous researches have been conducted in recent years to control and limit the presence of microorganisms by integrating traditional heat treatments with irradiation systems (gamma, UV, ultrasound, etc.) or with mechanical systems (UHP); the application of these techniques is currently very limited and the heat treatments are the most widely used for the pasteurization or sterilization of biological products.
DIC sterilization exploits both phases of this thermo-mechanical treatment:
the conditioning phase is used to considerably reduce the number of microorganisms present in the product to be treated and to introduce the necessary amount of energy into the system;
the Decompression phase is used to favor the explosion and / or damage of the cell walls of residual microorganisms and to rapidly cool the product.
DIC sterilization therefore allows the protein and vitamin content of the treated material to be better preserved than traditional thermal techniques and is effective both on microorganisms in the developed phase and on those in the sporular phase.
This technique also lends itself to being optimized for delicate pharmaceutical and cosmetic processes, such as the production of high purity enzymes and antibiotics.
In addition to the evident improvements in terms of the effectiveness of the technique and the quality of the finished products, DIC Debacterization has the advantage of being able to be applied on biological products in any form (in pieces, in powder, in paste or liquid) with simple plant adaptations.