The “Continuous Ventilex“ system has been developed for the decontamination of herbs and spices to make them safe for human consumption without adverse effect on the organoleptic characteristics and appearance ( flavour/taste and colour).

Special design features allow for the processing of ground products as well as whole products.

The word “decontamination” is used as the process aims at a safe product and not at a sterile product; this means that micro-organism that are hazardous for heath or causing food spoilage shall be eliminated. Many processing plants are able to comply with these conditions, but not all of them without adverse effect on the quality of the final product that should please the consumer.

Pasteurizing and sterilizing of milk in the dairy industry has learned that “IN-FLOW” processing in a ST-HT (short time-high temperature) process gives products with better organoleptic characteristics than has been possible with a batch process because the heat load on the product could be reduced by fast heating and fast cooling.

The same applies in principle for heat sensitive herbs and spices and especially if large quantities per hour need to be decontaminated. The total cycle time for a batch autoclave with a content of 5 cubic meter content might take as long as 45 minutes for heating and cooling.

The process time for the product in the continuous Ventilex autoclave is generally 25-35 seconds after which the product meets a sterile flow of filtered air for cooling and drying in the Ventilex fluid bed dryer/cooler which is directly connected to the sterilizer.

Cooling and drying of the product in a batch autoclave is mainly obtained by the application of vacuum after the product has reached the required sterilizing temperature. It is the vacuum that removes an important quantity of the essential oils while the long heat treatment damages the appearance.

With the Ventilex concept the product is cooled to a temperature below 55 °C within 30 seconds, which means that the product is never longer subjected to a temperature above 55 °C longer than one minute.

The “log-reduction” with the Ventilex system is mainly a function of the chosen steam temperature which is infinitely variable adjustable between 102 and 122 °C. The final moisture content of the product leaving the dryer/cooler is mainly a function of the selected air temperature in the drying section.

Typical steam temperatures in the autoclave are 119-120 degree for whole black pepper, 116-118 °C for paprika powder and 102-105 °C for herbs like marjoram and basil.
The temperature will depend on the initial plate count, type of micro organism to be removed and particle size. Heat resistant spore formers like Bacillus Cereus require a minimum temperature of 115 °C.

Typical design details of the Ventilex sterilizer are the self cleaning rotary valves for product feed and discharge and the variable speed shaker bed serving the internal conveying of the product through the system in a way that the difference in treatment time for each part of the product flow is less than 4 %.
The shaker bed design allows for automatic CIP (cleaning in place). The Ventilex system has been validated by the FDA in the USA.

The system is controlled by a central control panel validated for data logging.

Microbiological quality of products treated with the Ventilex system:

Total count: less than 10.000 Cfu/g
Entero bacteriaceae:  less than 10 Cfu/g
Salmonella: absent in 25 grams
Yeasts and moulds: less than 10 Cfu/g
Bacteria spores:  Bacillus Cereus less than 100 Cfu/g
Clostridium Perfringers: less than 100 Cfu/g
Staphylococcus Aureus: less than 100 Cfu/g