METHOD FOR FOOD PRESERVATION

Description

TECHNICAL FIELD

[0001] This invention relates to food preservation.BACKGROUND

[0002] Today there are literally hundreds of patents describing various method or techniques for extending the life of foods and drinks. These patents typically describe three basis techniques or combinations thereof. The intent of just about all of these devices is to reduce the amount of oxygen which makes up 21% of air to which the consumable is exposed. Of course, reducing the temperature, as in refrigeration, slows down the process of bacteria growth and extends the life span of food and drinks, but is not considered is this analysis.

[0003] The first technique involves creating a vacuum. In reality, only various degrees of a partial vacuum are created. As the vacuum level is increased (lower pressure), the amount of oxygen available to react with the food or wine is decreased and the life of the material is increased. The challenges associated with this approach are that vacuum systems are expensive, containers to sustain low pressures are expensive, and only a portion of the oxygen is removed providing limited benefits. Even with a high-level vacuum capable of reducing the pressure to 0.345 bar (5 psi) absolute (approximately one-third of atmospheric pressure), only two-thirds of the oxygen has been removed. In other words, one-third of the oxygen remains.

[0004] The second technique, and by far the most popular, is to replace air (21% oxygen) with an inert gas such as nitrogen or argon. The concept around this approach is quite simple. By replacing the air (oxygen) with these inert gases, the amount of oxidation and deterioration of the consumable, is reduced. This technique is used worldwide and does indeed result in the enhanced shelf life of food and wine. Systems that significantly reduce the level of oxygen (0.1 to 1 %) have extended the shelf life of wines indefinitely while food has been extended by months. However, there are many issues associated with the technique. The use of inert gas has been found to be a cost-effective means of preserving consumables on a large-scale basis, but most homes and facilities do not have easy access to these types of gases. While there are dedicated businesses already established that bottle and distribute these gases to major consumers of the gases, this method does not lend itself to the typical user because of gas delivery issues as well as the handling of the heavy high-pressure tanks in which the gases are maintained.

[0005] Finally the third approach uses chemicals to slow the deterioration of consumables. Needless to say, this is rather risky (possibility of chemicals entering the food chain) and quite costly. Consequently, the method is rarely used beyond well controlled preservatives in food and cosmetics.

[0006] JP H08 294322 A describes storage equipment capable of storing objects in an atmosphere at low oxygen concentrations at reduced labor and cost for maintenance and equipment cost. A storehouse stores objects and a housing vessel contains an oxygen scavenger. There is equipped a circulating channel so as to start from the inside of the storehouse via the housing vessel and then return to the inside of the storehouse again. The returning flow channel of the circulating channel is furnished with a mixing valve to mix the air with the gas in the channel. The gas in the channel is circulated by a fan. Besides, a sensor detects the oxygen concentration of the gas inside the storehouse. When the sensor detects the oxygen concentrations other than a specified value, a control unit drives the fan and also controls the mixing valve according to the value detected by the sensor.

[0007] US 2018 / 0245835 A1 describes a container refrigeration apparatus that includes: a casing which forms an external storage space communicating with the exterior of the container and an internal storage space communicating with the interior of the container; a refrigerant circuit; an external fan; an internal fan; and an inside air control system including an exhaust passage which allows a space on a blowout side of the internal fan in the internal storage space to communicate with the external storage space, and controls composition of the inside air in the container. An external end of the exhaust passage is open on a suction side of the external fan in the external storage space.

[0008] CN 101 322 575 A describes a preservation refrigerator and a matched oxygen concentration regulating device. The light oxygen reduction preservation refrigerator comprises a refrigerating chamber, an extraction port and an air injection port, the extraction port and the air injection port are communicated with the oxygen concentration regulating device by a corresponding extraction pipeline and an air injection pipeline, a main body of the device is an oxygen concentration regulator with the light response mode, the extraction pipeline is communicated with an air inlet of the oxygen concentration regulator, the air injection pipeline is communicated with an air outlet of the oxygen concentration regulator, electromagnetic valves are both connected on the extraction and the air injection pipelines in series, an air pump is connected on the pipeline of the extraction pipeline or the air injection pipeline within the electromagnetic valve in series, the oxygen concentration regulator, the electromagnetic valves and the air pump are connected with a control circuit. The mode utilizes the characteristics of oxygen absorption and oxygen release of the light response material under the radiation of the ultraviolet with the different wavelengths, the control is convenient, the regulation of the oxygen concentration and the oxygen reduction preservation refrigerator can be further realized by being matched with a simple control element.SUMMARY

[0009] The invention is defined by the appended claims.

[0010] According to the invention, a system for removing oxygen from a container includes a recirculation pump, an oxygen removal device, and a low pressure bleeder valve. The recirculation pump includes an intake and a discharge, and the intake includes a first connector fluidically connected to the container. The discharge is fluidically connected to an oxygen removal device. The oxygen removal device includes an inlet fluidically connected to the discharge of the recirculation pump, an outlet including a second connector fluidically connected to the container, and an oxygen removal portion configured to remove oxygen from fluid passing from the inlet to the outlet. The low pressure bleeder valve is fluidically connected to the inlet of the recirculation pump and configured to introduce additional fluid into the system in response to a pressure in the system being below a predetermined threshold.

[0011] According to the invention, a method for removing oxygen from a container includes drawing fluid from the container via a recirculation pump, passing the fluid through an oxygen removal device, wherein the fluid comes into contact with oxygen removal material, ORM, that scavenges oxygen from the fluid, resulting in an oxygen depleted fluid, returning the oxygen depleted fluid to the container, and, in response to a pressure in the container falling below a predetermined amount, introducing new fluid to the container.

[0012] The system described offers many advantages over previous systems. First, excellent preservation performance as measured in extended shelf life / low oxygen levels is achievable. The performance can be delivered all along the food chain from the farm, through distribution, retail and ultimately home or retail use. This capability can be highly valued in both established as well as emerging markets. Secondly, there are no burdensome gas tanks that continually need to be refilled and / or transported. Thirdly, the final oxygen content of the container can be controlled with no intervention and held to very low levels. Fourthly, the cost can be reasonable. Finally, utilizing oxygen absorbing materials that allows for the discharge of the oxygen back into the environment is politically, commercially and environmentally correct, and very advantageous from a marketing and operational perspective.

[0013] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is an example food preservation system. FIG. 2 is an example of a food preservation system in accordance with the present invention. FIG. 3 another example of a food preservation system

[0015] Like reference symbols in the various drawings indicate like elements.DETAILED DESCRIPTION

[0016] FIG. 1 illustrates an example food preservation system 100. The system 100 can generate a substantially inert gas environment. In these instances, the system 100 can slow the deterioration of the consumables that is not only cost effective but an efficient solution for oxygen removal from food and wine containers. The system 100 can be applied to any items (clothes) adversely affected by the presence of oxygen. A reduced oxygen environment can reduce mold, and its associated smell, and can reduce or eliminate insects from attacking the garment.

[0017] Currently, fruit frequently are placed in sealed containers just prior to being fruit ripened. In these instances, the fruit ripens using the trapped oxygen which is depleted, and the fruit then continues to be preserved for months, as long as the container is not opened thereby allowing oxygen to enter. The illustrated system 100 can store ripened fruit and then reduce or remove the oxygen slowing or preventing further ripening and spoilage.

[0018] As illustrated, the system 100 includes a circulating system 102 that extracts oxygen from air resulting in an inert gas or substantially inert gas in an atmospheric pressure environment. The circulating systems includes a circulating pump 104 that includes a canister 106 filled with oxygen reducing material (one time disposable or rechargeable multi use material) from which the oxygen reduced gas is pumped into the enclosed container 108 including, for example, food, bottled goods, clothes, or other items. The gas from the container 108 is then recirculated through the air pump 104 and the oxygen removal process is repeated for the specific container 108. The process can be repeated for other containers.

[0019] The system 100 can include an oxygen reducing material, other techniques not yet known could be developed in the future and subsequently applied to the proposed system 100. These might be vacuum-based or electric-field-based as examples.

[0020] The recirculation can provide multiple advantages. First, the oxygen removal in the container 108 will not be 100% efficient for any practical system. If only a portion of the oxygen is removed as it passes through the container 108, a lower limit of a final oxygen content in the container 108 can be set. As an example, 60% oxygen removal can result in 8% oxygen (40% of the original 20% oxygen content in air) remaining in the container 108. Even if the oxygen removal was 90%, the gas in the container 108 can still have 2% oxygen. But recycling the oxygen deprived gas exiting the container 108 can result in a continually reduced oxygen content. Table 1 is an example that demonstrates the residual oxygen after each cycle.Number of Cycles

[0021] % Oxygen Removal 1 2 3 4 5 4012%7.20%4.32%2.59%1.56%5010%5.00%2.50%1.25%0.63%608%3.20%1.28%0.51%0.20%706%1.80%0.54%0.16%0.05%804%0.80%0.16%0.03%0.01%902%0.20%0.02%0.00%0.00% Even with an oxygen absorption efficiency of only 70%, the oxygen content in the container can drop below 0.6% in, for example, 3 cycles and below 0.1% in, for example, 5 cycles.

[0022] The system 100 can be closed to more efficiently use the oxygen absorbing material. When recycling the gas through the canister 108, less oxygen is typically removed with each cycle. No matter how many times the cycle is performed, the amount of oxygen removed is from the original 20% of the container 108. That said, the container 108 may have insignificant leaks that contribute additional oxygen to the system 100. To be technically accurate, due to pressure equalization (final pressure of container to be approximately atmospheric), the amount of oxygen removed can equal to about 25% of the original volume of air.

[0023] The oxygen removal material (ORM) can be rechargeable. In some instances, the ORM can be treated with perhaps heat or UV so that the oxygen is released and then the ORM is reused to remove oxygen again. In these instances, the recharging can occur within the system 100.

[0024] FIG. 2 is an example food preservation system 200 for automating the preservation method in accordance with the present invention. As illustrated, the system 200 includes locking snap connectors 202a-d on the input and output of the container 108. In these instances, the recycling unit 102 can be quickly connected and disconnected to the container 108. The system 200 includes electronics 204 to control the operation (On / Off, timing, etc.) of the pump 104. One-way valves can be used in place of ON / OFF valves or the snap connectors 202. As an example, a one-way valve can be used to allow air into the system 200 as the oxygen is removed. The cost of these items is typically less than $1. The current system 200 includes a low pressure bleeder valve 206.

[0025] Proper controls could be implemented in order to optimize performance of the system 200. As an example, the system 200 can be set to run for a given period of time. With different size containers, the operator can select a container size or simply allow the system 200 to run for extended periods of time (e.g., minutes, hours) to remove most or all the oxygen.

[0026] FIG. 3 illustrates an example preservation system 300. As illustrated, the system 300 includes an oxygen sensor, which then allows the controller to turn off the pump when the oxygen level falls below a certain level.

[0027] An indirect and more cost-effective means of monitoring the oxygen level could be through the use of a pressure sensor 302. As the oxygen level is reduced, the pressure inside the closed system / container will be reduced. Monitoring this pressure reduction, as well as the rate change in pressure, allows for an accurate determination of the oxygen content. This technique would circumvent having to know the container volume or the efficiency of the oxygen absorbing material, which could change with usage.

[0028] Table 2 is listed below and lists estimates for medium quantities, and based upon the assumption that the material used to extract oxygen from the air will be rechargeable (heat or light used to discharge the oxygen). Items Cost Two lock connectors and stopper$2.00Two lock connectors$1.50Pump$6.00Filter housing$3.00Low pressure valve$0.75Tubing$0.50Housing$5.00Electronics / panel$4.00Oxygen absorbing material$6.00Assembly labor$2.50Total $31.25 Although the systems 100-300 has been described as standalone, it should be noted that this could be a subsystem included into other systems. As an example, today's refrigerators have enclosed storage containers to store vegetables, fruits, etc. The proposed systems 100-300 can be built into the refrigerator such that when the containers are opened and subsequently closed, the oxygen reduction recirculating system 102 would be activated either manually or by sensing the closure. As the refrigerator becomes more "intelligent", this subsystem can be built directly into and monitored by the refrigerator.

Claims

1. A system (100, 200, 300) for removing oxygen from a container (108), the system comprising: a recirculation pump (104) comprising an intake and a discharge, wherein the intake comprises a first connector fluidically connected to the container, and the discharge is fluidically connected to an oxygen removal device (106); the oxygen removal device comprising: an inlet fluidically connected to the discharge of the recirculation pump; an outlet including a second connector fluidically connected to the container; and an oxygen removal portion configured to remove oxygen from fluid passing from the inlet to the outlet; and a low pressure bleeder valve (206) fluidically connected to the inlet of the recirculation pump, wherein the low pressure bleeder valve is configured to introduce additional fluid into the system in response to a pressure in the system being below a predetermined threshold.

2. The system (100, 200, 300) of claim 1, wherein the oxygen removal device further comprises: an oxygen release system comprising: a release path configured to permit fluid flow from the oxygen removal portion of the oxygen removal device out of the system; and an energy source configured to impart energy on the oxygen removal portion of the oxygen removal device sufficient to cause the oxygen removal portion to release scavenged oxygen, and optionally wherein the energy source is ultraviolet light or heat or electric field or vacuum.

3. The system (100, 200, 300) of any one of claims 1 or 2, further comprising: oxygen removal material, ORM, embedded in the oxygen removal device and along a flowpath from the inlet to the outlet, wherein the ORM absorbs oxygen on contact.

4. The system (100, 200, 300) of claim 1 or claim 3, wherein the first connector and second connector each comprise snap disconnects that prevent fluid flow when disconnected.

5. The system (100, 200, 300) of claim 1 or claim 3, further comprising: a first valve connected between the first connector and the recirculation pump; a second valve connected between the second connector and the oxygen removal device; a pressure sensor configured to sense a pressure in the system and generate a sensed pressure signal; and a controller configured to open and close the first and second valves, and activate the recirculation pump based on a pressure signal from the pressure sensor.

6. The system (100, 200, 300) of claim 1 or claim 3, wherein the system is integral to a containerized storage device, wherein the containerized storage device comprises one or more containers.

7. A method for removing oxygen from a container, the method comprising: drawing fluid from the container via a recirculation pump; passing the fluid through an oxygen removal device, wherein the fluid comes into contact with oxygen removal material, ORM, that scavenges oxygen from the fluid, resulting in an oxygen depleted fluid; returning the oxygen depleted fluid to the container; and in response to a pressure in the container falling below a predetermined amount, introducing new fluid to the container.

8. The method of claim 7, further comprising: receiving an first pressure measurement associated with a pressure in the container; determining a target pressure for the container associated with removing oxygen from the container; opening one or more valves to allow fluid flow; running the recirculation pump; receiving a second pressure measurement associated with the pressure in the container; in response to the second pressure measurement being equal to or less than the target pressure: closing the one or more valves; and stopping the recirculation pump.

9. The method of claim 7, further comprising: determining a scavenging efficiency; in response to the scavenging efficiency being below a predetermined threshold: opening one or more valves to permit fluid flow from the ORM to an external area; and exposing the ORM to an energy sufficient to cause the ORM to release scavenged oxygen, and optionally wherein the energy is ultraviolet light or heat.

10. The method of claim 7, further comprising controlling a humidity within the container.

11. The method of claim 7, wherein the container is one of one or more containers that form a containerized storage device.