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Title:
PROCESS FOR PRESERVING PERISHABLE GOODS
Document Type and Number:
WIPO Patent Application WO/2018/154609
Kind Code:
A1
Abstract:
It is disclosed a container (1) aimed at containing perishable goods, which can be sealed after storing the goods inside it, comprising at least one valve (5, 6) to let the gas flow in one and/or in the other direction, wherein said at least one valve (5, 6) acts in a first process (5) preventing gas from coming out from inside the container and a second process (6) preventing gas from entering the container (1) from outside. Said container (1) also comprises a vacuum gauge, a dosed air intake system. It is also disclosed a process for the preservation of perishable goods, comprising the following steps: a) introducing perishable goods into a container (1) comprising at least one valve (5, 6) to let the gas flow in one and/or in the other direction, in a way (5) adapted to prevent gas from coming out from inside the container and in a second way (6) to prevent gas from entering the container from the outside; b) sealing the container (1); c) removing a substantial part of the air left inside the sealed container (1); d) introducing an amount of oxidising gas through one of the gas valves (5); e) the oxidising gas is left inside the container for 1 to 5 minutes, preferably 1 to 3 minutes; f) creating vacuum inside the container by sucking out the gas through one of the gas valves (6). According to the present invention, the process also comprises the following steps: g) checking that the pressure inside the container is below a given threshold; h) if the threshold is exceeded, extracting the gas until a lower threshold is reached; i) introducing air slowly and gradually. Preferably, said oxidising gas is ozone. According to a third aspect, it is also disclosed an ozone settler in a closed circuit.

Inventors:
VERCELLINO PIERANGELO (IT)
Application Number:
PCT/IT2017/000032
Publication Date:
August 30, 2018
Filing Date:
February 22, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
VERCELLINO PIERANGELO (IT)
RAGANELLI VALERIO (IT)
International Classes:
A23L3/3409; A23B7/152; A23L3/3445; B65D81/20
Domestic Patent References:
WO2001067877A22001-09-20
WO2005030275A12005-04-07
Foreign References:
JPH0938181A1997-02-10
US20060150829A12006-07-13
US20070193915A12007-08-23
JPH10327829A1998-12-15
US20130251863A12013-09-26
GB2531381A2016-04-20
CN106178815A2016-12-07
CN204637985U2015-09-16
EP0988800A12000-03-29
Attorney, Agent or Firm:
VATTI, Francesco Paolo (IT)
Download PDF:
Claims:
CLAIMS

1) Container (1) aimed at containing perishable goods, which can be sealed after storing the goods inside it, while comprises at least one valve (5, 6) allowing gas to pass in one and/or in another direction, wherein said at least one valve (5, 6) triggers a first process (5) preventing gas from coming out from inside the container or a second process (6) preventing gas from entering the container (1) from outside, characterised in that it also comprises a vacuum gauge, a dosed air intake sys- tem, said vacuum gauge controlling the dosed air intake, and an ozone settler (11) that turns ozone into oxygen.

2) Container (1) according to claim 1} , characterised in that it is a large bag, the bottom of which is reinforced by an additional plastic layer.

3) Container (1) according to claims 1) or 2) , characterised in that the check valve (5) that prevents gas from coming out or the single valve are equipped with an input air filtering device.

4) Container (1) according to claim 3) , characterised in that the filtering device is a sterile filtering body, the maximum pore size of which does not exceed 0.2 μια.

5) Process for the preservation of perishable goods, comprising the following steps: a) inserting perishable goods into a container (1) comprising at least one valve (5, 6) to let pass in a direction and/or in another one in a way (5) as to prevent gas from coming out from inside the container and in another way (6) as to prevent gas from entering the container from the outside; b) sealing the container (1) ; c) creating the vacuum inside the sealed container (1) ; d) introducing a quantity of oxidising gas through one of the gas valves (5) ; e) leaving the oxidizing gas inside the container for as long as it is necessary according to temperature; f) creating vacuum inside the container by sucking out the gas through one of the gas valves (6) , characterized in that it also comprises the following steps: g) checking that the pressure inside the container (1) is below a certain threshold; h) if the threshold is exceeded, extracting the gas from inside the container, until a lower threshold is reached; i) slowly introducing measured out air quantities .

6) Process according to claim 5) , characterised in that the addition of said oxidizing gas inside the container (1) leads to a slight overpressure.

7) Process according to claims 5) or 6) , characterised in that said oxidising gas is ozone.

8) Process according to any one of claims 5) to 7) , characterized in that said slow and gradual inlet of air during step i) is performed by letting in ambient air, which goes through a sterile filtering body.

9) Process according to claim 7) , characterized in that the said slow and gradual inlet of air during step i) is performed by turning on an ozone settler (11) that turns ozone - that was fed into the container (1) - into oxygen.

10) Ozone settler (11) to be used in a closed circuit, characterised in that it is made of one or more electrical re- sistances, able to bring the temperature to a given value.

11) Settler (11) according to claim 10) , characterized in that this temperature value is in the range between 55 and 80 °C.

12) Ozone settler according to claims 10) or 11) , characterized in that it is preferably made of an envelope of polymer- ic material with low transmittance and low thermal conductivity, with a stainless-steel serpentine or thick net resistance.

Description:
PROCESS FOR PRESERVING PERISHABLE GOODS

DESCRIPTION

The present invention relates to a container for packing and storing perishable goods, as well as to a process using such container.

The package of the goods for transport and sale to retail stores is one of the most important problems that must be tackled by the industrialised society. What is particularly important, is to properly pack goods, so as to rationalise space and to avoid that goods are damaged by any shocks occurring during transport .

As a general rule, packaging is classified into three categories .

Primary packaging contains one product in a single package, e.g. bags of crisps, fruit containers sealed by means of a heat- shrinkable plastic film, oil bottles and the like.

Secondary packaging is one large package, containing a number of pieces of primary packaging; e.g. six beer bottles packs, packs containing four bags of crisps, two magazines sold togeth- er, etc.

Tertiary packaging contains a number of pieces of primary and/or secondary packaging grouped in a batch, such as pallets, boxes and crates.

Additional problems arise when goods to be transported are perishable (which often occurs, especially in the food and pharmaceutical fields) . In this case, goods must be properly packed, so as to ensure the longest possible shelf life. Obviously, there are procedures able to ensure a long shelf life, but they often are detrimental for the properties of the goods. In par- ticular, the usual procedure is to add preservatives or to hot sterilise goods (see, for instance, UHT milk) .

Most procedures aimed at lengthening the life cycle of perishable products act in such a way as to prevent one of the two following basic mechanisms from happening: fermentation and oxi- dation. Fermentation is mostly due to bacteria. This is the reason why bacteria are eliminated by introducing harmful substanc- es targeting bacteria (preservatives) or by eliminating the conditions needed for them to survive (e.g. vacuum-packed products) . Oxidation occurs in the presence of air. Also in this case, vacuum-packing products can be useful, or antioxidants may be added, such as sodium metabisulphite in wines or on the fruit and ascorbic acid in non-alcoholic drinks. All things considered, the use of preservatives having oxidising properties seems to be critical, since, in this way, the degradation mechanism (fermentation) is not triggered, but the other mechanism (chemi- cal oxidation) might be facilitated. However, this procedure was also explored.

EP 0 353 021 discloses a method to preserve goods that are easily perishable due to breathing, especially because of the formation of ethylene, which accelerates the ripening and dete- rioration of fruits, comprising the sealing of goods in a container inside of which the oxygen level is lower than what is needed for goods to breathe. The oxygen level is kept as desired by washing the gas used with another gas containing little or no oxygen. Gas can be washed before, during or after filling the container with perishable goods. Upon transporting the perishable goods, the oxygen level inside the container is constantly monitored. When the oxygen level is too high, the oxygen-free gas is injected again in the container and when it is too low, air is let in. Preferably, the oxygen-free gas is C0 2 . By using such a method, goods are passively preserved, since an oxygen- free atmosphere is created, in such a way as to slow down oxidation and fermentation. However, anaerobic bacteria are neither eliminated nor deactivated.

US 5 481 852 discloses a preservation process intended for perishable goods and a device to implement it, which envisages the exchange of gas inside a sealable container. The exchange of gas takes place by means of a check valve system. The process consists of placing a sealable container inside a chamber, capable of keeping a definite pressure in the container; keeping the container in fluid communication with the interior of the chamber; creating a first vacuum in the container, so as to remove the oxygen contained in it; injecting an oxidant and an inert gas into the container; creating a second vacuum in the container; injecting an inert; removing the container from the chamber. The breathing of some products is not taken into account by this system, e.g. fruits: the complete lack of oxygen creates anaerobic conditions (or anaerobic breathing) , and thus worsens the quality of the preserved product. Moreover, as for fruits and vegetables, cells continue to breathe and - should the air be totally devoid of oxygen - they die.

US2011/0 268 850 discloses a method to preserve foods and drugs, comprising packaging in a modified atmosphere containing C0 2 and oxygen, with a variable ratio between 9:1 and 1.5:1. Even in this case, the breathing needs of some perishable products are not taken into consideration, and no oxidant is used to disactivate or eliminate anaerobic bacteria.

CN 105 192 054 discloses a food smoking agent, comprising high levels of C0 2 . Under such an atmosphere, perishable goods are treated by using an oxidant. Fruits breathing is not mentioned.

CN 102 422 879 discloses a method for prolonging the preservation of Chinese pears, while also reducing the associated load of pesticides. Ozone is introduced into the environment where pears are contained, at a temperature of about 2°C and a humidity rate between 90 and 98%. Ozone is kept in the room where the pears are for about 30 minutes, air is then let in, so that pressure goes back to atmospheric levels. The procedure is repeated every 1 to 3 weeks. Ozone decomposes rapidly, which is not taken into account. That is why large ozone quantities are used; however, the cost of ozone might exceed the benefits by far.

EP 2 107 936 discloses a method for preserving perishable goods in a refrigerator, where air is circulated and ozone is injected into its atmosphere. A monitoring system monitors the amount of ozone, and makes it possible to constantly adjust its concentration in the air, through a control and command system.

EP 1 530 431 discloses a method to lengthen the shelf life of perishable goods stored in warehouses, by keeping it under a controlled atmosphere, where the ozone content is higher than that in ambient air.

However, all these methods do not take into account a num- ber of disadvantages due to the particular system that is created. What is not taken into consideration is ozone being hazardous for living beings (particularly humans) , it is a very unstable, strongly oxidising and toxic molecule. The above described methods substantially trust ozone to naturally decompose. Howev- er, what is not taken into consideration is that after a relatively short time, ozone decomposes and is no longer active. Therefore, a too rapid decay of ozone would not completely suppress harmful micro-organisms and would be ineffective.

Ozone reducing systems are known according to which ozone is filtered through activated carbon filtres or by using chemicals. However, filtres are often expensive and must be frequently substituted, whereas chemicals are often polluting substances. Ultraviolet rays might also be used; however, they might cause skin cancer, for this reason their use is not recommended. The risk of ozone-related damages for workers decreases as the temperature to which workers are subjected increases.

The problem which this invention wants to solve is to develop a container structure which may be used to in any way transport perishable goods, which solves the above-mentioned is- sues, which allows the storage and transport of perishable goods and which may keep the organoleptic characteristics of the product unchanged, even for very long time. This will be done in a safer way for all the workers involved (they will not be uselessly and unnecessarily exposed to toxic gases, such as ozone) , it will also achieve the full elimination of micro-organisms that cause goods to decay and it will prevent anaerobiosis phenomena from affecting the stored goods. According to a first aspect, this object is achieved by means of a container aimed at containing perishable goods, which can be sealed after storing the goods inside it, which comprises at least one valve allowing gas to pass in one/or in another direction, wherein said at least one valve triggers a first process to prevent gas from coming out from inside the container or a second process to prevent gas from entering from outside the container, characterised in that it also comprises a vacuum gauge, a dosed air intake system, said vacuum gauge controlling the dosed air intake, and an ozone settler that turns ozone into oxygen.

According to a second aspect, the present invention relates to a process for the preservation of perishable goods, comprising the following steps: a) inserting perishable goods into a container comprising at least one valve to let gas in and out, in such a way as - first - to prevent gas from coming out from inside the container and in such a way as - second - to prevent gas from entering the container from the outside; b) sealing the container; c) removing a significant part of the air that is still inside the container; d) introducing a quantity of oxidising gas through one of the gas valves; e) leaving the oxidising gas inside the container for as long as it is necessary on the basis of the temperature; f) creating vacuum inside the container by sucking out the gas through one of the gas valves, charac- terised in that it also comprises the following steps: g) checking that the pressure inside the container is below a certain threshold; h) if the threshold is exceeded, extracting the gas from inside the container, until a lower threshold is reached; i) slowly introducing dosed out air quantities.

According to a third aspect, the present invention relates to a closed-circuit ozone settler, characterised in that it consists of a few electrical resistances introduced in the circuit and used to bring the temperature to a predetermined level and keeping it at that level for a predetermined time.

The dependent claims describe preferred features of the invention.

Further features and advantages of the invention will anyhow be more apparent from the following detailed description of a preferred embodiment, given by mere way of non-limiting exam- pie and illustrated in the accompanying drawings, wherein:

Figure 1 schematically shows an open container according to the present invention, prior to and during its filling;

Figure 2 schematically shows the container of figure 1 after being sealed;

Figures 3 and 4 schematically show the container of figures 1 and 2 during two steps of the method according to the present invention;

Figures 5 and 6 schematically show the container according to the present invention, according to a preferred embodiment; and

Figure 7 shows an embodiment of a container according to the present invention, in its pre-assembly step.

Before entering into the detailed description of the invention, it must be pointed out that it refers to the preservation of perishable goods and aims to avoid the damages caused by fer- mentation and breathing to perishable goods, whereas the present invention does not take into account any possible damage that the goods may suffer because of shocks.

A container 1 according to the present invention is highly outlined in the drawings. Container 1 can be of any type. It is preferably a flexible container, such as a bag or a film - since this kind of container is easily completely emptied and it is easier to understand quickly if air has entered from the outside into the container, in addition to that the container is easily transportable and, under vacuum, it can be easily stored; however, this invention can advantageously be also applied to a rigid container 1, such as a box or a crate (for simplicity, as shown in the drawings) . A preferred embodiment of the container 1 is a large bag, the bottom of which is reinforced by an additional plastic layer. Said reinforcement should preferably be added upon filling the bag 1, since its presence from the very beginning would make it difficult to store and transport the bag; such reinforcement allows the bag 1 to be easily transportable by using forklift or the like.

The bag 1 looks like the bag shown in figure 7 before being filled up, and it can be closed by hinges, as it is the case with a playing dice . Container 1 is made of two parts 2, 3. These two parts 2, 3 of said container 1 may be sealed together by a connection 4. Connection 4 can be of any type, provided that it provides a watertight seal to the outside. For instance, it may be a hot welded connection, glued by means of an adhesive agent, a watertight hinge and so forth. If a soft container 1 is used (or, anyway, a non-rigid container) , it is advisable to apply at its fastening 4 a spring jaw, which should be preferably as long as the entire fastening of container 1, so as to help the sealing of the opening in a safe and reliable way. It must be understood that such spring jaw does not replace connection 4, but it merely works with it to prevent accidental opening in the event of shocks or excessive overpressure, which could be caused by an accident or the like.

According to an embodiment of the present invention, and as shown in the drawings, part 2 carries a check valve 5, while part 3 carries a check valve 6. The two check valves 5, 6 can of course also be placed on the same part, 3 or 2 , of container 1, without thereby departing from the scope of the present inven- tion. Check valves 5, 6 stop the gas flow going in opposite directions. In the example shown in the drawings, valve 5 prevents gas from coming out of container 1, whereas the check valve 6 prevents gas from entering container 1. According to a preferred embodiment, it is appropriate that the check valve 6 is located in the part that is kept upwards during storage and hacheck- ndling of the container, as shown in the drawings.

Alternatively (not shown in the drawings) , one single valve can be envisaged, which can be driven alternately for letting gas in or out of container 1; in such a case, it is recommended that said valve is placed in that part of the container which is kept upwards during storage and handling.

Check valve 5 preventing gas from coming out of the container or just the single valve show, preferably, an inlet air filtering device (not shown in the drawings) and possibly a smoke filtre. Such a device can be fixed on the valve, or it can be mounted when needed. The filtering device is intended to pre- vent micro-organisms from entering the container 1. For this purpose, the filtering device is, preferably, a sterile filtering body, the maximum pore size of which does not exceed 0.2 m.

Figures 3 and 5 show a suction system 7 connected via a pipe 8 to the check valve 6. In the above described alternative case, it may be connected to the single valve. The suction system 7 is any suction device, of a known type, that is able to create a vacuum inside the container 1.

According to the invention, a vacuum gauge (not shown) is connected to valve 6, and it is suitable to detect pressure inside the container 1. The vacuum gauge, of a known type, is also operatively connected to the suction system 7.

Figures 4 and 6 show an oxidising gas feeding system 9, connected via a pipe 10 to the check valve 5. In the alternative case, it may be connected to the single valve. The feeding system 9 can be a cylinder (as shown in figures 4 and 6) , but it can also be a device producing oxidising gas (which is the only possible alternative in the case of ozone, since it cannot be stored) . According to a preferred embodiment, the oxidising gas is ozone, given that it is an oxidising gas and can be easily produced from the air and has no polluting residues and/or contaminants. In addition to this, ozone not only eliminates microorganisms from perishable goods, but also traces of pesticides and, in some cases, it renders heavy metals and non-metals harm- less. In any case, since ozone can be harmful (especially to people) , an ozone settler 11 is mounted - as shown in figures 5 and 6- inside pipe 8 (and possibly also inside pipe 10) , which converts ozone into oxygen, so that ozone levels in the working environment cannot reach high levels. The ozone settler 11 is preferably located upstream of the suction system 7 to prevent oxidation. The ozone settler 11 is preferably made of an envelope of polymeric material, with low transmittance and low thermal conductivity, with a stainless-steel serpentine or thick net resistance. In this way, the high temperatures are not let out of the system and workers do not run the risk of being burned. The use of stainless material is recommended in order to prevent it from being damaged by ozone, which is a highly oxidising agent .

According to the present invention, such a settler consists of one or more electrical resistances that bring the temperature to a certain value. Such a value is preferably comprised between 55 and 80°C. The selected temperature range takes into account that the ozone half-life is a function of temperature (at room temperature it is about 20 min.). At 25 °C is 10 min. At 32 °C is 5 min. At 39 °C is 2.5 min. At 47 °C is 1 min. 15 sees at 54 °C, 37.5 sees at 61 °C and 0 sec at 69 °C. These values explain why the chosen range is the best possible choice, since a lower flow rate allows a full settlement, even as for the lower values of the temperature ranges. Obviously, ozone levels may be decreased according to the known technique, without that - because of this - this container and this method are not included in the scope of the present invention any more.

A dryer can also be added to the system (not shown in the drawings) , especially if container 1 is a large container. The system can be operated by supplying electric power from the grid or by using suitable batteries or accumulators.

In the following, the process to pack and preserve perishable goods according to the present invention is described. Although such a process may be used to transport perishable goods, it is especially suitable for storing goods in stock.

During the first step (see figure 1) the container 1 is open and, through the opening between parts 2 and 3, perishable goods are placed into it. Upon completing the filling procedure, connection 4 is adequately created, which must keep the container 1 sealed, i.e. connection 4 must prevent gas from flowing to and from the inside and outside of the container 1 (see figure 2), unless gas flows through the check valves 5, 6 (or through the single valve) and only according to the directions allowed by the valves and when they are purposely open.

At a later step, vacuum is created inside container 1. Ac- cording to a preferred embodiment, this step takes place by sucking air from the inside. In this way, a first, sharp reduc- tion of the micro-organisms to be eliminated is achieved. Said suction takes place by connecting a pipe 8 of a suction system 7 to the valve 6 that does not allow air to be let into the container 1 (see figure 3) with the open valve 6, whereas the other valve 5 is kept closed, so as to prevent air from being sucked from the outside. If there is a single valve, its output is driven and the valve is open and pipe 8 is connected to the valve, similarly as it has just been shown. The suction system 7 may be any known type of suction system, such as a pump, a com- pressor, a blower, etc. Valve 6 - or the single valve - allows gas to flow from the inside to the outside of container 1, but not from the outside to the inside of container 1. In such a way, after creating a light vacuum (for example, around 0.6 bar) , pipe 8 can be safely removed before closing valve 6, with- out air flowing back into container 1. If, according to a preferred embodiment, valve 6 is located in the upper part of the container, ethylene is sucked out more quickly and completely, ethylene being a substance coming from fruit breathing and it greatly contributes to its decay. As a matter of fact, C0 2 which is formed due to ethylene conversion during breathing, is heavier and thus ethylene floats first to the top of container 1; if valve 6 is located at the top, greater quantities of ethylene are let out. At this step, the ozone settler 11 is kept off. C0 2 cylinders are thus not used.

After closing valve 6, a pipe 10 is connected to valve 5, the former is connected to a source 9 of oxidizing gas and valve 5 is opened. If there is only a single valve, it must be closed, pipe 8 must be disconnected, pipe 10 is connected and the valve opening is driven towards the inlet opening into the container 1. The oxidizing gas is now let inside container 1. Valve 5 - or the single valve - allows gas to flow from the outside to the inside of container 1, but not from the inside to the outside of container 1. In this way, the inside of container 1 is filled with oxidising gas, a slight overpressure being preferably cre- ated (for example the inside pressure might be around 2 bars) . Thanks to the vacuum that has been created during the previous step and being present within containerl, the oxidising gas fills up even the smallest spaces kept within the perishable goods very rapidly, so as to be highly effective: the absence of other gases removes hindrances to the motion of the oxidising gas and, since a number of oxidising gases (such as ozone) decay over time in any case and become less active, the most complete action is possible. As already said, the preferred oxidising gas is ozone, which can be easily produced from the air and with remarkable antibacterial properties. It is also extremely cheap. In addition, at the end of the process, no organic or inorganic residues are left, except oxygen. The oxidising gas source 9 may be a cylinder (as shown in figure 4) or an ozone producing device, of a known type. If the ozone settler 11 is assembled into the system, it is off at this step, since ozone must enter the system as such. After letting in the oxidising gas, valve 5 - or the single valve - closes and the gas remains under pressure inside container 1. The possible presence of ozone settler 11 - which is now turned on - inside pipe 10 - prevents residual ozone that is still inside pipe 10 from getting out after the feeding of ozone has stopped, and being harmful to worker's health.

According to an alternative embodiment, the step of removing a substantial part of air from the inside of container 1, instead of sucking air from the check valve 6 (as shown in fig- ure 3) , is done by letting in through the check valve 5 that prevents gas from flowing out from the inside (as shown in figure 4) a certain amount of oxidizing gas, and by leaving open the other check valve 6 for the first period. In this way, the oxidising gas entering container 1 from the check valve 5 pushes the air inside the container through valve 6 (which is left opened, as said), and replaces the air inside container 1. Air is let out, partly mixed with an increasing concentration of oxidising gas. When it is considered that the outgoing gas, which is flowing out from the check valve 6, has the desired concen- tration of oxidising gas, the check valve 6 is closed, so that the oxidising gas creates the desired pressure inside container 1. Also in this case, the inflow of the oxidising gas is stopped and the check valve 5 is closed.

As already said in the introduction, the inflow of an oxidising gas inside container 1 allows to eliminate a significant number of bacteria (if not all) causing the fermentation of perishable goods. The residence time of the oxidising gas will have to take temperature into account; to this purpose container 1 is suitably equipped with a thermometer. Note, however, that a residence time shorter than 1 minute causes the bacterial species causing goods degradation not to disappear completely, so fermentation is anyway triggered, even under anaerobic conditions, although the triggering of fermentation is slower and, therefore, goods will be preserved much longer than if no treatment is envisaged, but it will not be sufficient and, in any case, degradation will take place in a short period of time. When ozone is used, a too long residence time causes ozone to turn into oxygen, thus restoring the conditions favourable to the growth of bacteria and therefore goods start to decay. Furthermore, fruit decay due to oxidation would be pushed beyond any acceptable limit. In such a way, a longer storage than if no treatment is envisaged would take place, however storage of goods already partly damaged and, therefore, which could even not be used. The above described cycle could also be repeated more than once, so as to adjust the total residence time of ozone in the container 1 on the basis of the possible bacteria that need to be eliminated. For example, if streptococcus needs to be eliminated, the cycle must be repeated 4 to 5 times, so as to fully eliminate it. Indeed in order to eliminate these bacteria, it is suitable to expose them to ozone for about 20 minutes at 32 °C. It is thus possible 4 cycles of 5 minutes between them cycles vacuum being created.

After the residence time and/or after performing the needed number of cycles, valve 6 is opened and connected again to pipe 8 of the suction device 7 , by turning on the ozone settler. If there is a single valve, the opening is driven towards the outgoing direction from container 1 and pipe 8 is then connected thereto. Device 7 is turned on and ultra-vacuum conditions are created. If container 1 were a soft container, its internal walls would be made adhere to the goods contained therein. In this way, the oxidising agent is completely eliminated, so as to prevent goods from being damaged. Also in this case the ozone settler positioned in pipe 8 prevents ozone from leaking into the surrounding environment while emptying container 1, thus avoiding harmful consequences for workers' health. This step prevents micro-organisms from entering container 1 again, thus starting again the decay of the goods.

According to this invention, the goods stored in container 1 are allowed - to a certain extent - to breathe oxygen, so as to avoid anaerobiosis and to convert the generated ethylene into C0 2 , so as to slow down any damage caused to the goods by the ethylene. For this reason, the gas contained in the container is kept within a range between an upper and a lower limit. Prefera ¬ bly, the content of oxygen in container 1 varies between 0.4 and 3% by weight, still preferably it is around 2% by weight. What must be taken into account that 2% oxygen means about 0.18 atm. Thanks to the vacuum generated inside container 1, oxygen can easily fill up all the areas inside container 1, even the far ¬ thest areas from the inlet . The minimum amount of oxygen introduced will not damage the goods, and will reduce the ethylene content. In this way, the duration of goods preservation will be further extended.

Step i) of the method can be performed by following two possible variants, which will now be illustrated.

According to a first process variant, after creating the vacuum inside the container 1, air is allowed in through valve 5. The valve filtering medium will prevent micro-organisms from entering the container, which might also restore the initial conditions, favourable to the goods decay. In such a way, sterile conditions are maintained, and the air presence does not shorten the preservation time that can be achieved thanks to this invention. On the other hand, the presence of air prevents anaerobiosis from occurring, thus minimising the rate of goods decay. The injected air, free of bacteria and having a too low concentration to trigger goods oxidisation, reacts with the substances (mostly gaseous) created by the stored goods. In the case of fruit, for example, oxygen may transform ethylene that is generated over time into C0 2 , thus further slowing down fruit decay. The vacuum gauge sends a signal causing the air inflow to stop upon reaching the upper threshold, in order to avoid overpressure. Preferably, the air inflow is achieved by using a known device, e.g. a solenoid valve. At the same time, the vacu- um gauge sends a signal to the suction device, which will turn the device on and so gas (containing mostly C0 2 , water vapour, ethylene, terpenes and oxygen traces) will be extracted. After the suction, when pressure inside container 1 decreases and reaches the lower threshold, the vacuum gauge sends another sig- nal to the suction device 7, and the device is turned off. At the same time, the air inlet is opened again and the cycle continues. Another way to manage this part of the method is adjusting the air inflow and extraction time, so as to allow to maintain the concentrations of the desired species inside the con- tainer 1, for instance using a timer and a solenoid valve. In this case, the air inflow time should be adjusted according to the flow. This process variant is particularly useful for preserving meat: as a matter of fact, if air is let in, a quantity of nitrogen is also let in, which helps to preserve meat.

As seen, an embodiment of the present invention envisages an ozone settler 11 positioned in pipe 8. In this case, after the ozone inflow has ended, the settler is activated, it reaches the settling temperature and acts as a source of pure oxygen. The presence of the ozone settler 11 can be exploited in a sec- ond variant of step i) of the process indeed, owed to the ozone settler 11, ozone is transformed into oxygen; this oxygen is pure and can be breathed by the perishable goods, thus avoiding the inlet of ambient air and no filters on valve 5 are needed. In addition, this method is preferable with respect to other methods to obtain pure oxygen, e.g. water electrolysis, catalysis and the like. Even in this case, in order to maintain an ox- ygen content equal to 2% by weight, ozone should be fed at a pressure of 74/75 atm, in order to take into account that three oxygen molecules are obtained from two ozone molecules . The oxygen fed into the system according to this process variant is particularly pure since its source is ozone where no microorganism can survive, so it is completely free of microorganisms. This variant is particularly suitable for the preservation of fish and allows a very precise oxygen dosage.

In whatever way step i) is carried out, contrarily to what happened in the prior art, it is possible to exactly dose the amount of oxygen fed to the container 1 for cell breathing of the goods contained therein.

The use of the ozone settler 11 only to eliminate ozone from the environment surrounding the process (and not to feed pure oxygen inside the container 1 according to this second variant) falls of course within the scope of the present invention.

When the preservation phase is completed and container 1 is ready to be sent to sale, pipes 8, 10 and the vacuum gauge are disconnected, the inner part of container 1 being placed under vacuum, and it is sent to its destination.

Container 1 and the process according to the present invention allow to extend - even for a long time - the life of perishable goods, even if compared to the common vacuum containers, and they are very useful, especially as for foodstuffs. In this way, it is even possible to suppose the preservation of fresh milk in the same way as UHT milk, without applying any ultrahigh temperature treatment, so as to completely preserve the organoleptic properties of the milk. Obviously, this invention is especially useful for foodstuffs such as meat and fruits, and as for the latter, it is even possible to suppose its preservation beyond its normal season, thus out-of-season fruit may be available and it would be grown on plants and not in greenhouses, thus having a much better taste. Container 1 and the process according to the present invention are able to eliminate the phe- nomenon of heating of perishable goods; as a matter of fact, because of this, large amounts of perishable goods are discarded (and thus wasted) , thus supporting considerable economic and health advantages. This process according to the present invention allows to eliminate bacteria, viruses, moulds and yeasts, but also other substances that may damage the goods, such as traces of pollutants, such as pesticides, thus obtaining a level of food safety never achieved before. As for grapes, for instance, it has been recently discovered that the ozone treatment increases the antioxidants content, thus making it particularly good for human health. What has been especially found out is that, after being treated with ozone, the polyphenols content increases 4-fold.

Also, small containers 1 for household use can be developed, in order to improve the preservation of home-cooked food. This should also help to improve food safety, since the achieva- ble sterility might help to prevent botulism and other similar toxicological phenomena from occurring, also for home-made preserves and sausages .

The container, the process and the ozone settler according to the present invention allow a reduction of manufacturing costs, even if compared to the systems used in the prior art making use of ozone. Moreover, oxygen and C0 2 cylinders are not used; they could cause issues due to their non-trivial management and cost increases. Moreover, goods do not need to be stored in warehouses, since they could also be stored outdoors. It is to be pointed out that this invention also allows food waste to be greatly reduced. Food waste is not only morally reprehensible, but it is also a source of significant economic losses, especially for families (estimates state that about 40% of all food is wasted) . This invention also allows not to use cooling. A further advantage is that the container and the process according to the present invention work effectively, irrespective of size and scale.

The present invention allows the preservation of fresh products in a controlled atmosphere in order to slow down the production of ethylene and the breathing of fruits, by using the technique preferred by the user, and slowing down the decrease in quality. For example, the U.L.O. technique with low values of oxygen (1.0% 0 2 - 1.0% C0 2 ) may be used; or the ILOS technique may also be used, i.e. a very low dose of 0 2 , followed by the ULO (Ultra Low Oxygen) atmosphere. This is the dynamic adaptation of the controlled atmosphere (D.C.A.) : this process can be judged as fundamental for organic products, because in the future organic products will not be allowed to undergo any post-harvest process neither by using DPA (Diphenylalanine) nor M.C.P. (SMAR -FRESH) . All these preservation processes, even the latest processes that have been developed, even those processs that had been - up to now - only applicable inside a storage cell, are now made available by the present invention.

It is understood, however, that the invention is not to be considered as limited by the particular arrangement illustrated above, which represents only an exemplary embodiment of the same, but different variants are possible, all within the reach of a person skilled in the art, without departing from the scope of the invention itself, as defined by the following claims.

For instance, it is possible, after removing ozone, a fur- ther adding step of an inert gas. Particularly advantageous results have been obtained by adding C0 2 , which, for example, makes fruits crispier.

LIST OF REFERENCE NUMERALS

1 Container

2 Part (of 1)

3 Part (of 1)

4 Connection (between 2 and 3)

5 Check valve

6 Check valve

7 Suction device

8 Pipe

9 Oxidizing gas feeding system

10 Pipe

11 Ozone settler