PEX-Process:
The PEX technology (Product EXpanding) is a quasi-continuous "refinement process" patented in several countries, in which pre-dried fruits and/or vegetables (so-called SD products > semi dried; 15 to 30 % water content) are preserved by dehydration to below 2% water content.
The SD products are always delivered in cleaned and calibrated condition, cut into cubes, strips, slices, etc. There is therefore practically no need for organic waste on site.
The SD products are placed in product trays (with 800mm Ø) in a geometrically specially designed vessel, which is equipped with microwave transmitters. After a short temperature-controlled heating of the product by microwaves, the vessel is evacuated abruptly. Under vacuum and further exposure to microwaves a "puffing" of the product takes place (PEX > Product EXpanding). During this treatment step, the cell structure of the product is simultaneously changed by disintegration, whereby high-quality product properties (such as significantly higher taste intensity!) are achieved without damaging the product. At the usual working pressure of approx. 20 mbar in the PEX process, the water contained in the product starts boiling and evaporates already at approx. +17°C.
In a further process step, the product trays are transferred to a fully automatic infrared post-drying unit for final drying of the products - while maintaining or lowering the vacuum - and brought to any desired residual moisture content. Before the final product is removed, the product trays are temporarily stored on cooled heat exchanger plates to ensure that the final products retain their shape. After the product trays have been removed from the vacuum, the final packaging is done in in bags with suitable barriers for the specific product in e.g., nitrogen atmosphere. Thus, the high quality of the end products is maintained for a long time. The PEX process has already been in use for approx. 10 years and there is very good operating experience.
In the meantime, the quasi-continuous PEX technology has been further developed and supplemented, so that today a fully automatic, continuous ("fifo" = first in - first out) PEX technology can be offered.
If it is desired to start with "freshly harvested" raw material (e.g., when setting up the plant at the place of cultivation), suitable washing, peeling, cutting and drying plants should be installed upstream of the PEX process.
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Enhanced PEX-process - the „INVAP”- process
In addition IFM is delivering an enhanced PEX process, which is called the "INVAP”- process.
More than 10 years proven technology to produce healthy and crispy snacks from fruits and vegetables!
By combining already proven basic components, a completely new production concept was developed, which has not yet been available on the market in this form. The technology is called INVAP refining process and stands for INert-VAcuum-Puffing. In this process, the dehydration (drying) of the products, from the beginning (= fresh product) to the end (= dried product) is carried out consistently under an "inert atmosphere" and in a "vacuum". This eliminates oxidation reactions that inevitably occur in conventional drying systems (tray dryers, belt dryers, etc.). Since the drying circuit is closed, the process drying conditions always remain constant.
Using the PEX(C) process, the INVAP technology is a continuously operating process (fifo principle > first in - first out), i.e. the same product treatment times. A suitable cutting and separation technology is available for the product banana.
The advantage of "INVAP" technology is that the dehydration cycle is completely sealed and as a result, oxidation reactions (as they inevitably occur with the drying systems normally used tray dryers, belt dryers, etc.) are excluded. Below is shown the difference of both processes with highly sticky fruits with a high tendency to oxidation leading to brownish discoloration - such as bananas.
This allows for the best fruit products and the healthiest, most delicious snacks ever created.