PROCESS FOR TREATING MYCOTOXINS AND RESPECTIVE PLANT

The present invention relates to a process for treating mycotoxins .

The invention further relates to a plant for implementing said process.

More in particular, the invention relates to a technological process in order to eliminate or significantly reduce the presence of mycotoxins in foodstuffs such as grains, seeds, dried fruit, etc intended for human and/or animal consumption.

As it is known, the foodstuffs are generally subjected to machining operations (for example in the mills and in the dryers) such as brushing, crushing (in various particle sizes) , dividing (in various particle sizes) , grinding, until obtaining flour and middlings.

The patent document n. DE 32 09 930 discloses a

treatment methodology that provides the following steps in the listed order:

1) inserting the goods in a room

2) creating a vacuum

3) introducing ozone into the room, and keeping it for a time from 30 to 300 min

4) inserting ammonia in the room, and keeping it for a time from 30 to 300 min

5) removing the vacuum, rinsing with water to create ammonium chloride, to be reused for other purposes

6) washing the filter and pumping air

7 ) removing goods .

However, this method has the limitation of obtaining a food product yet provided with the unpleasant odor of ammonia, with the obvious consequences of the case.

In particular, such technology, even if detoxifying the foodstuffs, does not allow easy application in animals breeding because they refuse the product which was so treated, due to the residual odor of the ammonia.

In this context the solution suggested according to the present invention is included, which introduces, in the procedure for processing foodstuffs, processing with the purpose of eliminating, or at least greatly reduce, the presence of mycotoxins, while at the same time keeping the same smell and flavor of the treated produc .

These and other results are obtained, according to the present invention, proposing a process for treating mycotoxins which requires the use of ammonia and ozone. Therefore specific object of the present invention is a process for treating mycotoxins, in particular in foodstuffs, which provides, in the indicated order, the steps of:

a) displacing the foodstuffs in a first device of containment and transport , i.e. for example a box containing a cochlea;

b) supplying ammonia or ammonium hydroxide;

c) storing foodstuffs within a storage device (for example, a silo) for 60-90 minutes;

d) supplying gaseous ozone;

e) stocking.

Advantageously, such sequence of operations, and in particular the use of the ozone subsequently to that of the ammonia, allows: - oxidizing the residual ammonia which is on the food product, dissociating it from the latter;

- whitening the product that was possibly darkened by the ammonia, as for example in the case of the corn. According to the invention, preferably, the step of permanence of the foodstuffs within the storage device for 60-90 minutes occurs at a temperature of 45-55°C. Advantageously, this range of temperatures has been shown to be optimal for treating cereals, as it is effective, avoiding to dry the cereal and/or to lead to a too consistent weight loss.

In particular, such temperature may be preferably of 50°C.

Always according to the invention, the step of supplying ammonia may occur with a quantity variable between 0,5 kg and 4 Kg for each ton of foodstuffs to be treated.

In such case, according to the invention, the quantity of the step of supplying ammonia varies in proportion to the level of humidity of foodstuffs.

Further, according to the invention, during the step of permanence of the foodstuffs within the storage device for 60-90 minutes, a step of taking the air which is within the storage device from a hole placed in a first end of the storage device, ducting the air, filtrating the air, heating the air and pushing the air within the storage device through a series of nozzles placed in correspondence of a second end of the storage device, occurs .

This promotes advantageously recirculation of air, allowing controlling the temperatures of the processing of the product, and - further - also allows controlling the distribution of the gaseous ammonia within the storage device.

Preferably, according to the invention, pushing the air within the storage device from a second end occurs through one or more diffusing devices, preferably five or more. Such diffusing devices allow a uniform distribution of the supplying ammonia, with the purpose of ensuring that the whole product comes into contact with the ammonia within the silo.

Further, according to the invention, during the step of storing foodstuffs within the storage device for 60-90 minutes, a step of controlling the temperatures and the concentration of ammonia by means of an automatic system of probes and meters may be performed, in order to advantageously avoid the danger of explosion.

Additionally, according to the invention, after the step of storing foodstuffs within the storage device for 60-90 minutes, a step of transferring the foodstuffs into a second device of containment and transport, a step of insufflating vapour into the second device of containment, and a step of sucking the vapour out, may occur.

Advantageously, the treatment with vapour allows:

- removing the ammonia from the foodstuff, since it is heated by the vapor, it becomes unstable and

evaporates ;

- moistening the surface of the grains and,

consequently, - ozone fixation in water.

In particular, the sequentially use of vapour and aqueous ozone, subsequent to that of ammonia, allows:

- eliminating the odor of ammonia making the foodstuff attractive to animals;

- regaining the original aroma of the treated product;

- the product gains a brighter color.

In such case, according to the invention, the step of insufflating vapour within the second device of containment and transport may occur in correspondence of a first end of the second device of containment and transport, and the step of suction of the vapour may occur in correspondence of a second end of the second device of containment and transport.

Always according to the invention, before the step of supplying gaseous ozone, a step of cooling and drying the foodstuffs may occur.

Preferably, according to the invention, the step of supplying gaseous ozone occurs in a third device of containment and transport, preferably in a series of four or more devices of containment, as for example boxes containing cochleae .

Further, according to the invention, the step of supplying gaseous ozone may occur with a quantity varying between 500 and 1.000 grams per 10 tons of treated foodstuffs.

In particular, according to the invention, before supplying the ammonia, the product may be brushed in order to reduce the presence of the mycotoxins and increase the treatment speed. Further according to the invention, in case of application on divided foodstuff, a step of dividing, a step of crushing and a step of grinding may be provided, allowing considerably increasing the total surface area of contact and increasing the efficacy of the treatment, also promoting the reaction on mycotoxins in the grain.

Additionally, according to the invention, in case the foodstuff is moist after the step of supplying gaseous ozone, a step of drying may be provided before the step of stocking.

Preferably, according to the invention, the ammonia is used in its anhydrous form, and may be supplied on the foodstuff directly in its gaseous form or, once dissolved in water, by spraying the ammonia-water solution.

Further according to the invention, the ozone is used in its gaseous form and may be supplied on the foodstuff directly in its gaseous form or, once dissolved in water, by spraying the ozone-water solution.

In particular, if the ozone is supplied directly in its gaseous form, the quantity of used ozone varies between

0.0001 kg for each kg of foodstuff to be treated and 0,003 kg for each kg of foodstuff to be treated.

The invention relates further to a plant comprising:

1. a first device of containment and transport or cylindrical box (step of supplying ammonia) , equipped with nozzles for injecting the ammonia and containing a cochlea with auger blades for moving the foodstuff;

a storage device, for example a tank or a silo (step of permanence of the product in contact with ozone) which is loaded from top through the cochlea of the first box; this second storage device or tank is equipped with diffusing devices placed on the bottom, for supplying the ozone and with a hole at the top for the recirculation of the air mixed with ammonia;

a second device of containment and transport or U-shaped box (step of supplying vapour) , equipped with nozzles for injecting the vapour and containing a cochlea with auger blades, suitable for supplying vapour and for expelling vapour and gaseous ammonia;

a third device of containment and transport, for example a cylindrical box containing a cochlea with auger blades for moving the foodstuff, possibly suitable for supplying ozone;

a fourth device for containment and transport, for example a U-shaped box for possible drying (step of drying) containing a cochlea with auger blades for moving the foodstuff;

a fifth device for containment and transport, comprising a series of more U-shaped watertight boxes (for example four) for supplying ozone, each containing a cochlea with auger blades for moving the foodstuff ;

possibly a steel tank for stocking the decontaminated product. The invention relates further to a plant comprising a recirculation system of the air enriched with ammonia; such air enriched with ammonia is taken from a hole placed at the top of the tank, ducted, filtered, heated and pushed by fans into the tank through a net of diffusing devices allowing the gas being distributed uniformly and being in contact as much as possible with the foodstuff .

Within the silo, since the oxygen content is kept lower than 17%, possible risk of combustion resulting from simultaneous presence of oilseeds and oxygen (oxidizing) is prevented, a sensor that continuously monitors said parameter being provided, so that, in case the threshold value of the oxidizing quantity exceeds, nitrogen gas is introduced into the plant.

The invention will be now described for illustrative but not limitative sake, with particular reference to the drawings of the attached figures, in which:

figure 1 shows schematically a cylindrical box containing a cochlea with auger blades for moving the foodstuff, suitably equipped with nozzles for supplying ammonia according to the invention;

figure 2 shows a plant according to the invention.

The process according to the invention provides the use of specific substances supplied in a liquid and/or gaseous form.

In particular, the substances used in the process according to the invention are ammonia and ozone. Said substances may be used both directly and dissolved in water. In any case, regardless of the type of use, said substances will be indicated in the following as "reactants" .

In the following the quantities for the individual reactants used in the process according to the invention will be provided.

Ammonia

The ammonia is used in its anhydrous form, and may be supplied on the foodstuff directly in its gaseous form or, once dissolved in water, by spraying the solution ammonia-water.

If supplied directly in its gaseous form, the quantity of used ammonia varies between 0,0001 kg for each kg of foodstuff to be treated and 0,1 kg for each kg of foodstuff to be treated.

If supplied dissolved in water, the percentage by weight of solute dissolved in the solvent is in the range 5% - 30%, while the quantity of solution used varies between 0,005 kg for each kg of foodstuff to be treated and 0,03 kg for each kg of foodstuff to be treated.

Ozone

The ozone is used in its gaseous form and may be supplied on the foodstuff directly in its gaseous form or, once dissolved in water, by spraying the ozone- water solution.

If supplied directly in its gaseous form, the quantity of used ozone varies between 0,0001 kg for each kg of foodstuff to be treated and 0,003 kg for each kg of foodstuff to be treated.

If supplied dissolved in water, the solute is brought to saturation in the solvent; the reactant solution (water saturated with ozone) is supplied by nebulisation in a quantity varying between 0,005 kg for each kg of foodstuff to be treated and 0,03 kg for each kg of foodstuff to be treated.

In both cases, the contact time between the reactant and the contaminated foodstuff is in the range between 5 minutes and 90 minutes. This range is determined by the level of contamination and by the process the foodstuff has been submitted.

The process for treating mycotoxins according to the invention will be now described in the following, with reference also to the attached figures.

Looking at the attached figure 1, the contaminated foodstuff is moved by means of cochleae with auger blades 1, in order to obtain a homogenization between the reactant and the same foodstuff, while this one advances to the next treatment or, at the end, to the stocking tank.

During the tests carried out on the field, it was demonstrated that, by treating the divided corn with gaseous ammonia and stocking it for 60-90 minutes at the temperature of 45-55 °C, an almost total removal of the aflatoxins is obtained.

Nevertheless, the product so treated darkens quickly. This makes the same product - as well as unpleasant to the eye - inedible because of the strong presence of the used chemical agent, i.e. the ammonia.

In order to obviate these drawbacks, the treated corn with ammonia is subjected at first to a treatment with vapour for eliminating the residual ammonia, then possibly to a reduction of temperature, bringing at room temperature using a cold air flow and subsequently to a treatment with gaseous ozone.

The treatment with gaseous ozone allows the restoration of the original color and the total elimination of the smell and taste of ammonia. The process works continuously.

According to a favorite embodiment of the invention, which provides treating from 10 to 50 tons of product for hour, the process provides the following steps, in the listed numerical order.

Step 1: Treatment with ammonia.

A first cochlea 1, within a cylindrical box suitably equipped with nozzles for supplying ammonia, carries the corn (in grain, crushed, divided or in middlings) from the place it is stocked to the top of a silo S, for the containment of the foodstuff in contact with air and ammonia; already in this step within the closed cylindrical box 2 within which the cochlea 1 rotates, anhydrous ammonia is insufflated with a quantity variable between 0,5 kg and 4 Kg for each ton of product to be treated. Such quantity varies in proportion to the level of humidity of the grains .

The product, with the addition of ammonia, enters from top in the watertight silo S and is stocked inside it for a period varying between an hour and 90 minutes at the temperature of 50°C. Within the silo S, the rich in ammonia hot air is continuously recirculated, being taken from the top A of the silo S, ducted, filtered, heated (by a special boiler) and pushed by a fan (not shown) within the silo S from its lower part B, through one or more diffusing devices, preferably in a number higher than or equal to five; during this step the addition of further ammonia is possibly provided.

In particular, the diffusing devices have the object of ensure uniformly insufflating air, which is enriched with ammonia, so limiting to a minimum the creation of preferential paths for the above mentioned gaseous mixture.

The air recirculating allows the reduction of the energy costs for heating the product and the ammonia used for the treatment .

In a preferred embodiment of the invention, an automatic system of probes and meters allows keeping the temperatures and the ammonia concentration controlled, avoiding the danger of explosion (explosivity concentration limits of the ammonia: lower limit 15%, upper limit 28%) . In this step the presence of mycotoxins is reduced between the 95% and the 100%. The treated food product with this process undergoes a darkening caused by contact with ammonia.

Step 2: Eliminating the ammonia.

The corn is withdrawn from the bottom B of the silo S and it passes through a duct C then through a second closed U-shaped box 3 by means of a cochlea 3' placed inside, for supplying vapour V and for obtaining the spill of vapour and ammonia.

The residual ammonia, contained in the treated product, makes it unusable because of the (reversible) organoleptic abnormalities, such as the taste, the smell and the color. The ammonia which is in the grains is eliminated by the insufflating vapour within the above said second box 3. The vapour V, directed according to the narrows shown in figure 2, permeating the cereal, binds to ammonia (stripping of ammonia) and is at once eliminated by means of an intake plant.

Supplying the vapour V occurs by injecting at the bottom B' of the second box 3 containing a cochlea 3', while the suction of the vapour V saturated with ammonia occurs from the top A' of the same second box 3.

Step 3: Cooling and drying.

At the exit from the box 3 , the treated product with the vapour V enters in a close cylindrical box 6 containing a cochlea with auger blades 6' for moving the foodstuff and for loading them in the third box 7 for cooling, containing a cochlea with auger blades V for moving the foodstuff. In the U-shaped box 7 the product is invested by air F and then cold down to ambient temperature and dried from the condensed water which was due to the vapour V, while the product moves ahead by the cochlea with auger blades 7' to the next step .

As an alternative, it is possible that the vapour V is insufflated in the box 3 and then the product to be treated is subsequently cooled and dried in the same box 3.

Preferably, this step provides the use of a ventilation plant directing the air F to room temperature within the box 7 in which the grains pass .

The air moist is expelled by means of a suction system (not shown) .

Step 4 : Treatment with ozone

This step occurs preferably in a series of four or more airtight U-shaped boxes 8, for supplying ozone, equipped with a vent valve and each containing a cochlea 8' with auger blades for moving ahead the foodstuff to the next box. In such boxes a treatment of the food product with ozone occurs for eliminating possible residual ammonia and mycotoxins.

The ozone completes the drying of the cereal from the possible residual water which could remain from the step 3 and restores the organoleptic characteristics of the product, making it, in most of the cases, more brilliant and fragrant than unprocessed product.

Activity of the series of cochleae 8' allows preventing possible compaction of the grains and improving contact between the treated cereal and the ozone.

The quantity of ozone varies between 500 and 1.000 grams per 10 tons of treated grains.

At the end of the treatment, the product does not show any alteration from the organoleptic and nutritional point of view.

Observing the attached figures 1-2, the plant comprises :

a. a first device of containment and transport 2 or airtight cylindrical box (step 1) , equipped with nozzles 4 for injecting the ammonia and containing a first cochlea 1 with auger blades; a storage device S or tank/silo for containing the foodstuff in contact with air and ammonia, preferably in airtight steel with a vent valve and a recirculation system, for treating the foodstuff in gaseous ammonia (Step 1) ;

a second device of containment and transport 3 or U-shaped box (step 2) with lid and containing a cochlea 3' with auger blades, within which vapour V is insufflated for removing the ammonia, with suitable extractor;

a third device of containment and transport 6 or closed cylindrical box containing a cochlea 6' for moving the foodstuff to the next step;

a possible fourth device for containment and transport 7 or U-shaped box with a lid and with a cochlea with auger blades 7' for moving the foodstuff, within which the product is cooled and dried by means of insufflating air at room temperature;

a possible fifth device for containment and transport 9, comprising preferably a series of more U-shaped boxes 8 (in the shown embodiment, four boxes 8) with airtight lid, each equipped with nozzles for injecting the ozone and each containing a cochlea with auger blades 8 ' for moving the foodstuff;

a sixth device for containment and transport (not shown) or box with cochlea with auger blades for moving ahead the foodstuff to the place where it is loaded on the container 5 for stocking the decontaminated product .

In the foregoing the preferred embodiments have been described and variants of the present invention have been suggested, but it is to be understood that the experts in the art can make modifications and changes without departing from the relevant scope of protection, as defined by attached claims.