WO1998006281A1 - Oxygen scavenger accelerator - Google Patents

Oxygen scavenger accelerator Download PDF

Info

Publication number
WO1998006281A1
WO1998006281A1 PCT/US1997/013048 US9713048W WO9806281A1 WO 1998006281 A1 WO1998006281 A1 WO 1998006281A1 US 9713048 W US9713048 W US 9713048W WO 9806281 A1 WO9806281 A1 WO 9806281A1
Authority
WO
WIPO (PCT)
Prior art keywords
oxygen
packet
uptake accelerator
oxygen uptake
oxygen scavenging
Prior art date
Application number
PCT/US1997/013048
Other languages
French (fr)
Other versions
WO1998006281A9 (en
Inventor
Gary R. Delduca
Alan E. Deyo
Vinod K. Luthra
Wen P. Wu
Original Assignee
Tenneco Packaging Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tenneco Packaging Inc filed Critical Tenneco Packaging Inc
Priority to AU38933/97A priority Critical patent/AU3893397A/en
Publication of WO1998006281A1 publication Critical patent/WO1998006281A1/en
Publication of WO1998006281A9 publication Critical patent/WO1998006281A9/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A23FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23LFOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L3/00Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
    • A23L3/34Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
    • A23L3/3409Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor
    • A23L3/3418Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
    • A23L3/3427Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O in which an absorbent is placed or used
    • A23L3/3436Oxygen absorbent

Definitions

  • the present invention relates generally to a device and method for maximizing the rate of oxygen uptake of an oxygen absorber. More particularly, the invention relates to a method for accelerating the rate of oxygen uptake of an iron based oxygen scavenging packet specifically designed to be used in a packaging system designed to keep meat fresh.
  • Perishable foods such as meats, fruits, and vegetables are typically placed into packaging systems after harvesting in order to preserve these foods for as long as possible. Maximizing the time in which the food remains preserved, especially the time between initial packaging at the plant and delivery at the retail grocery store, increases the profitability of all entities in the chain of distribution by minimizing the amount of spoilage.
  • the environment in which the food is preserved is a critical factor in the preservation process. Not only is maintaining an adequate temperature important, but the molecular and chemical content of the gases surrounding the food is important as well. By providing an appropriate gas content to the environment surrounding the food, the food can be better preserved when maintained at the proper temperature or even when it is exposed to variations in temperature. This gives the food producer some assurance that after the food leaves his or her control, the food will be in an acceptable condition when it reaches the retail grocery store and ultimately, the consumer.
  • packaging systems which provide extremely low levels of oxygen are desirable because it is well known that the fresh quality of meat can be preserved longer under anaerobic conditions than under aerobic conditions. Maintaining low levels of oxygen minimizes the growth and multiplication of aerobic bacteria.
  • One way to insure a minimal level of oxygen in a meat package is to subject the package or rigid gas barrier materials to a vacuum in order to remove as much of the gas in the package as possible prior to sealing the package.
  • the package can then be sealed and the meat maintained in a "zero" atmosphere environment (commonly referred to as vacuum packaging).
  • vacuum packaging Under vacuum packaging conditions, red meat turns purple. Consumers, however, prefer to see their meat bright red. As a result, vacuum packaging has not been well accepted for consumer cuts of meat.
  • MAP modified atmosphere packaging technology
  • CO 2 carbon dioxide
  • N 2 nitrogen
  • Another less expensive means of insuring a minimal level of oxygen in a meat package is to use a gas flush MAP process.
  • the complicated steps of evacuating the package and refilling with the desired gas mixture are eliminated.
  • the outer bag (a barrier layer), is simply flushed with the proper gas mixture as it is formed around the inner container.
  • the flush process reduces the oxygen content of the package to about two percent.
  • An oxygen scavenger is placed in the package to absorb additional oxygen just prior to or simultaneously with forming and flushing the outer bag.
  • An excellent example of such a MAP system is described in the patent application entitled "Modified Atmosphere Package" filed on April 3, 1996, and given Serial No. 08/627,137.
  • a critical feature of a gas flush MAP packaging system is the ability to keep meat looking fresh and palatable. Oxidized meat turns an undesirable brown color. Accordingly, as discussed, an oxygen scavenger is typically placed inside the meat package in order to absorb any residual oxygen within the package after gas flushing and sealing the package. It is critically important to quickly remove the oxygen from meat to prevent it from turning brown. Especially important in preventing the irreversible change from red to brown is the rate at which oxygen is scavenged. If oxygen is removed quickly, the packaged meat turns a purple red color. This purple red color quickly "blooms" to a bright red color upon removal of the outer layer of packaging.
  • Oxygen scavengers are increasingly being used in packaging systems in order to protect various products from the detrimental effects of oxygen exposure.
  • oxygen scavengers utilize the oxidation of paniculate iron as a method to absorb oxygen.
  • a small amount of water is essential for this reaction.
  • a water attracting agent such as silica gel can be used to attract water and at times to supply water in the packet initially.
  • a major drawback to this technology is, however, the limited amount of water that can be supplied.
  • a major portion of the water needed for the oxidation of paniculate iron is provided by the product and/or packaging environment being protected. This is oftentimes an inadequate amount to promote the efficient and expedient oxidation of iron.
  • the slower the rate of oxygen reduction the more likely meat will turn irreversibly brown.
  • the present invention provides an iron-based oxygen scavenging packet which exhibits an increased rate of oxygen absorption especially in the confines of a concomitant meat packaging system.
  • the invention specifically provides an oxygen scavenging packet which comprises an iron-based oxygen absorber and an oxygen uptake accelerator comprising water.
  • the oxygen uptake accelerator accelerates the rate of oxygen uptake of the iron-based absorber.
  • the invention provides an oxygen scavenging packet which additionally contains an oxygen uptake accelerator in the form of an aqueous solution of acetic acid. Optimally, the acetic acid solution is of approximately five percent strength.
  • the present invention also provides a method of increasing the rate of oxygen abso ⁇ tion of an iron-based oxygen absorber by introducing an oxygen uptake accelerator into an oxygen scavenging packet containing an iron-based oxygen absorber.
  • an aqueous solution of acetic acid is introduced into the packet via injection, encapsulation in a rupturablc capsule, or by introduction by abso ⁇ tion through a wick.
  • the acetic acid solution that is introduced is of approximately five percent strength.
  • FIG. 1 illustrates an oxygen scavenging packet in which the oxygen uptake accelerator is being introduced into the packet via a syringe.
  • FIGS. 2a and 2b respectively, illustrate an oxygen scavenging packet containing a capsule which can be ruptured at an appropriate time to release the oxygen uptake accelerator and a packet containing a capsule being ruptured.
  • FIGS. 3a and 3b respectively, illustrate an oxygen scavenging packet including a protruding wick for abso ⁇ tion of the oxygen uptake accelerator into the packet and an oxygen scavenging packet in which the wick is being dipped into the oxygen scavenger accelerator.
  • FIG. 4 is an isometric view of the oxygen scavenging packet of the instant invention inside a modified atmosphere packaging system.
  • FIG. 5 is a graph illustrating the rate of oxygen abso ⁇ tion when a dry oxygen scavenging packet is introduced into a quart sized container which also includes 0.5 ml of water.
  • FIG. 6 is a graph illustrating the rate of oxygen abso ⁇ tion when an oxygen scavenging packet having 0.5 ml of water injected into the packet is introduced into a quart sized container.
  • FIG. 7 is a graph illustrating the rate of oxygen abso ⁇ tion as a function of the amount of water injected into oxygen scavenging packets.
  • FIG. 8 illustrates the rate of oxygen abso ⁇ tion in the presence of varying amounts of CO 2 utilizing an oxygen scavenging packet which has been injected with 0.6 ml of water.
  • FIG. 9 is a graph illustrating the rate of oxygen abso ⁇ tion as a function of the number of oxygen scavenging packets introduced into a one quart jar.
  • FIG. 10 is a graph showing the percent oxygen after 1 hour as a function of the amount of acetic acid (vinegar) injected into each of two oxygen scavenging packets.
  • FIG. 1 1 is a graph showing the percent oxygen as a function of time and as a function of the material injected into the oxygen scavenging packets.
  • FIGS. 1 through 3 depict an oxygen scavenging packet having a liquid oxygen uptake accelerator present in some form within the packet.
  • FIG. 1 depicts an oxygen scavenging packet 10 containing elemental iron 12 and in which an oxygen uptake accelerator 14 is introduced into the packet utilizing a syringe 16.
  • Injection can be performed manually with a syringe and hand placement of the packet inside the package.
  • the injection process can be automated by using a commercially available metering and dispensing pump such as the Beer Systematic model 45/50 and appropriate conveying equipment to position the packets for injection and then subsequently to place the packets into a package.
  • FIG. 2a depicts an oxygen scavenging packet 20 containing elemental iron 22 and in which an oxygen uptake accelerator 24 is present inside a capsule 26.
  • FIG. 1 depicts an oxygen scavenging packet 10 containing elemental iron 12 and in which an oxygen uptake accelerator 14 is introduced into the packet utilizing a syringe 16.
  • Injection can be performed manually with a syringe and hand placement of the packet inside the package.
  • the injection process can be automated by using a commercial
  • FIG. 3a depicts an iron-based oxygen scavenging packet 30 containing elemental iron (not specifically shown) and in which an oxygen uptake accelerator 32 can be introduced into the packet by abso ⁇ tion onto a wick 34 which protrudes from the packet.
  • FIG. 3b shows, the wick 34 dipped into the oxygen uptake accelerator 32.
  • An appropriate amount of oxygen uptake accelerator 32 is absorbed through the wick 34 into the packet 30.
  • the dipping occurs immediately prior to the sealing of the package in order to properly activate the iron based scavenger for accelerated oxygen uptake.
  • the instant invention particularly concerns an iron-based oxygen scavenging packet which contains an oxygen uptake accelerator consisting of water or an aqueous solution of some other substance dissolved in or mixed with water.
  • the oxygen uptake accelerator accelerates the rate of oxygen uptake of the oxygen absorber. Water alone will activate and accelerate iron-based oxygen absorbers via the presence of hydronium ions in the water. However, dilute acid solutions are preferred oxygen uptake accelerators. Acids provide increased numbers of hydronium ions which increase the oxidation rate of iron by acting as electron acceptors. These electron acceptors facilitate the ionization of neutral iron. Once ionized, the iron readily reacts with the available oxygen and water to form a hydrated iron oxide. Other electron acceptors such as the positively charged ions making up salt solutions or metals such as copper also facilitate the ionization of neutral iron.
  • the preferred aqueous solution of the instant invention is an aqueous solution which contains approximately five percent acetic acid.
  • the introduction of water or an aqueous solution of acid, salt or appropriate metal into the oxygen absorber packet of an iron-based oxygen absorber serves to activate and dramatically increase the rate of oxygen uptake of the iron inside the packet.
  • the paniculate iron in the packet in effect, turns to rust as oxygen is absorbed from the atmosphere surrounding the packaged meat or other packaged food product
  • the water or aqueous solution enhances oxygen abso ⁇ tion by the iron by acting as an electron acceptor.
  • a proposed mechanism for rust formation is as follows (2) e + H 3 O + ⁇ H + H 2 O
  • step (1) ferrous ions are produced by loss of electrons from the elemental paniculate iron in the packet. However, this process cannot go very far unless there is some way to get rid of the electrons which accumulate on the residual Fe
  • step (2) in which H 3 O + ions either from the water or from acid substances in the water, pick up the electrons to form neutral H atoms Since Fe is known to be a good catalyst for hydrogenation reactions in general, it is believed that step (3) now occurs to use up the H atoms.
  • the ferrous ion reacts with O 2 gas by step (4) to form the rust and restore H 3 0 + required for step (2).
  • the net reaction, obtained by adding all four steps is
  • Acid accelerates the reaction by providing excess hydronium ions (H 3 O + ) and driving step 2 Therefore, the preferred embodiment of the present invention utilizes a dilute aqueous solution of acid.
  • acid solutions should, of course, be compatible with food products and include, for instance, acetic acid and/or citric acid
  • Salt solutions also drive step (2) of the aforementioned reaction by providing an electron acceptor, thus they are suitable for use in the aqueous solution of the instant invention.
  • adding copper to water and/or dilute aqueous solution of acid speeds the rate of oxygen abso ⁇ tion by the iron. It is believed that the copper induces a phenomena called electrolytic corrosion. Electrons flow from the iron to the copper, where their energy is lower. This removes the excess negative charge from the iron.
  • H atoms which now form on the negative copper surface instead of the iron, detach themselves more readily from copper than from iron, thus accelerating step (3) of the aforementioned reaction.
  • the present invention also concerns a method of increasing the rate of oxygen abso ⁇ tion of an iron-based oxygen absorber by introducing an oxygen uptake accelerator comprising water or an aqueous solution into an oxygen scavenging packet containing an iron-based oxygen absorber.
  • an oxygen uptake accelerator comprising water or an aqueous solution into an oxygen scavenging packet containing an iron-based oxygen absorber.
  • the aqueous solution can be introduced into the packet utilizing an injection type process.
  • the solution can be included in the absorber packet in a separate capsule or compartment which can be ruptured at the time of sealing the meat package.
  • a wick could be included in, and protrude from, the packet such that the wick could be dipped in liquid just prior to sealing the meat package.
  • a preferred embodiment of the present invention involves the injection of an acetic acid solution of approximately five percent acidity into the MRM absorbers manufactured by Multiform Desiccants Inco ⁇ orated. This is done just prior to the placement of the absorber into a package. This can be done manually with a syringe and hand placement. Or, as discussed, the process can be automated by using a commercially available metering and dispensing pump such as the Heil Systematic model 45/50 and appropriate conveying equipment to position the packets for injection and then subsequently to place the packets into a package.
  • a commercially available metering and dispensing pump such as the Beer Systematic model 45/50 and appropriate conveying equipment to position the packets for injection and then subsequently to place the packets into a package.
  • the following data, depicted in FIGS. 5-11 is specific to Multiform's MRM 100 scavenger. All of these experiments involve using these scavengers.
  • the MRM 100 oxygen scavengers are specifically formulated to work in the presence of CO 2 and refrigeration.
  • FIGS. 5 and 6 illustrate that the oxygen uptake accelerator, in this case water, must be contained within the oxygen scavenging packet in order to increase the rate of oxygen abso ⁇ tion.
  • FIG. 5 shows the decrease in percent oxygen as a function of time when 0.5 ml of water is merely present in a quart-sized jar along with an oxygen scavenging packet.
  • FIG. 5 at 40°F it takes approximately 30 hours for the percent oxygen to be reduced to approximately 0.5% (5,000 PPM) and more than 40 hours for the percent oxygen to be reduced to near 0.0% oxygen.
  • FIG. 5 shows the decrease in percent oxygen as a function of time when 0.5 ml of water is merely present in a quart-sized jar along with an oxygen scavenging packet.
  • FIG. 5 shows the decrease in percent oxygen as a function of time when 0.5 ml of water is merely present in a quart-sized jar along with an oxygen scavenging packet.
  • FIG. 5 at 40°F it takes approximately 30 hours
  • FIG. 7 shows that the oxygen scavenging rate is maximized when 0.6 ml of water is present in the oxygen scavenging packet.
  • FIG. 8 shows that oxygen abso ⁇ tion appears to be independent of the amount of carbon dioxide in the container.
  • FIG. 9 shows that two oxygen scavenging packets absorb oxygen at nearly twice the rate of one packet.
  • acetic acid commonly known as vinegar acid
  • vinegar acid works particularly well in accelerating the rate of oxygen abso ⁇ tion of an MRM oxygen scavenger packet.
  • the injection of .5ml. of acetic acid into each of two absorber packets reduces the amount of oxygen in a quart jar to approximately .1% O 2 (1000 PPM) in one hour.
  • the percent O 2 is reduced to approximately .04% O 2 (400 PPM) in about ninety minutes when .5ml. of acetic acid is injected into each of two MRM 100 scavenger packets.
  • the present invention is particularly useful when used in a modified atmosphere packaging (MAP) process for fresh meats.
  • MAP process is a gas flush process that initially flushes the package to an oxygen atmosphere of about two percent or less.
  • the oxygen scavenging packet of the instant invention is utilized to additionally reduce the oxygen level of the package to 400 PPM (0.04%) or less within ninety minutes.
  • FIG. 4 depicts a modified atmosphere package 40 including an outer container 42 and an inner container 44.
  • the inner container 44 includes a conventional semirigid plastic tray 46 thermoformed from a sheet of polymeric material which is substantially permeable to oxygen.
  • Exemplary polymers which may be used to form the non-barrier tray 46 include polystyrene foam, cellulose pulp, polyethylene, polypropylene, etc.
  • the polymeric sheet used to form the tray 46 is substantially composed of polystyrene foam and has a thickness ranging from about 100 mils to about 300 mils. The use of a common polystyrene foam tray 46 is desirable because it has a high consumer acceptance.
  • the inner container 44 further includes a stretch film wrapping or cover 48 substantially composed of a polymeric material, such as polyvinyl chloride (PVC), which is substantially permeable to oxygen.
  • PVC polyvinyl chloride
  • the stretch film used to form the cover 48 contains additives which allow the film to cling to itself and has a thickness ranging from about 0.5 mil to about 1.5 mils.
  • One preferred stretch film is ResiniteTM meat film commercially available from Borden Packaging and Industrial Products of North Andover, Massachusetts.
  • a food item such as a retail cut of raw meat 50 is located inside the inner container 44.
  • the partially formed inner container 44 may be flushed with an appropriate mixture of gases, typically a mixture of about 30 percent carbon dioxide and about 70 percent nitrogen, to lower the oxygen level in the inner container 44 to about 1.5 to 5.0 percent.
  • gases typically a mixture of about 30 percent carbon dioxide and about 70 percent nitrogen
  • the foregoing mixture of gases displaces the oxygen within the inner container 44 during the flushing operation.
  • the tray 46 is manually or automatically wrapped with the cover 48.
  • the cover 48 is wrapped over the retail cut of raw meat 50 and about the bottom of the tray 46.
  • the free ends of the cover 48 are overlapped along the underside of the bottom wall of the tray 46, and, due to the cling characteristic inherent in the cover 48, these overlapping free ends cling to one another to hold the cover 48 in place.
  • the overwrapped tray 46 i.e., the inner container 44, may be run over a hot plate to thermally fuse the free ends of the cover 48 to one another and thereby prevent these free ends from potentially unraveling.
  • the outer container 42 is preferably a flexible polymeric bag composed of a single or multilayer plastics material which is substantially impermeable to oxygen.
  • the outer container 42 may, for example, include an oriented polypropylene (OPP) core coated with an oxygen barrier coating such as polyvinylidene chloride and further laminated with a layer of sealant material such as polyethylene to facilitate heat sealing.
  • OPP oriented polypropylene
  • the outer container 42 is composed of a multilayer barrier film commercially available as product no. 325C44-0EX861D from PrintPack, Inc. of Atlanta, Georgia.
  • the co-extruded film has a thickness ranging from about 2 mils to about 6 mils.
  • the inner container 44 Prior to sealing the peripheral edges of the outer container 42, the inner container 44 is placed within the outer container 42.
  • the outer container 42 is flushed with an appropriate mixture of gases, typically about 30 percent carbon dioxide and about 70 percent nitrogen, to lower the oxygen level in the outer container 42 to about 0.05 to 5.0 percent or 500 to 50,000 parts per million (PPM).
  • an appropriate mixture of gases typically about 30 percent carbon dioxide and about 70 percent nitrogen
  • PPM parts per million
  • the oxygen scavenging packet 52 lowers the oxygen level in the bag from its initial level of oxygen to less than about 0.04 percent or 400 PPM and most preferably to about zero percent.
  • the oxygen uptake accelerator contained within the oxygen scavenging packet 52 is responsible for this fast rate of oxygen abso ⁇ tion.
  • the oxygen scavenger 52 also absorbs any oxygen which might permeate into the outer container 42 from the ambient environment.
  • the oxygen scavenger 10, 20, 30, and 52 respectively is illustrated as a packet or label which is inserted into the outer container 42 prior to sealing the outer container 42.
  • an oxygen scavenging material may be added to the polymer or polymers used to form the outer container 42 so that the oxygen scavenging material is integrated into the outer container 42 itself.
  • the retail cut of raw meat 50 within the package 40 takes on a pu ⁇ le-red color when the oxygen is removed from the interior of the package 40.
  • the meat-filled modified atmosphere package 40 may now be stored in a refrigeration unit for several weeks prior to being offered for sale at a grocery store.
  • a short time e.g., less than one hour
  • the inner container 44 is removed from the outer container 42 to allow oxygen from the ambient environment to permeate the non-barrier tray 46 and non-barrier cover 48.
  • the pu ⁇ le-red color of the raw meat 56 quickly changes or "blooms" to a generally acceptable bright red color when the raw meat 56 is oxygenated by exposure to air.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Nutrition Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
  • Packages (AREA)

Abstract

An iron-based oxygen scavenging packet (10) is set forth in which the rate of uptake of oxygen is increased by virtue of the presence of an oxygen uptake accelerator such as water or dilute acid which is introduced into the packet. Methods of increasing the rate of oxygen absorption by the iron-based oxygen scavenging packet are also set forth.

Description

OXYGEN SCAVENGER ACCELERATOR FIELD OF THE INVENTION
The present invention relates generally to a device and method for maximizing the rate of oxygen uptake of an oxygen absorber. More particularly, the invention relates to a method for accelerating the rate of oxygen uptake of an iron based oxygen scavenging packet specifically designed to be used in a packaging system designed to keep meat fresh.
BACKGROUND OF THE INVENTION
Perishable foods, such as meats, fruits, and vegetables are typically placed into packaging systems after harvesting in order to preserve these foods for as long as possible. Maximizing the time in which the food remains preserved, especially the time between initial packaging at the plant and delivery at the retail grocery store, increases the profitability of all entities in the chain of distribution by minimizing the amount of spoilage. The environment in which the food is preserved is a critical factor in the preservation process. Not only is maintaining an adequate temperature important, but the molecular and chemical content of the gases surrounding the food is important as well. By providing an appropriate gas content to the environment surrounding the food, the food can be better preserved when maintained at the proper temperature or even when it is exposed to variations in temperature. This gives the food producer some assurance that after the food leaves his or her control, the food will be in an acceptable condition when it reaches the retail grocery store and ultimately, the consumer.
In meat packaging, in particular, packaging systems which provide extremely low levels of oxygen are desirable because it is well known that the fresh quality of meat can be preserved longer under anaerobic conditions than under aerobic conditions. Maintaining low levels of oxygen minimizes the growth and multiplication of aerobic bacteria.
One way to insure a minimal level of oxygen in a meat package is to subject the package or rigid gas barrier materials to a vacuum in order to remove as much of the gas in the package as possible prior to sealing the package. The package can then be sealed and the meat maintained in a "zero" atmosphere environment (commonly referred to as vacuum packaging). Under vacuum packaging conditions, red meat turns purple. Consumers, however, prefer to see their meat bright red. As a result, vacuum packaging has not been well accepted for consumer cuts of meat.
Another means of insuring a minimal level of oxygen in a meat package is to seal the meat in a refill modified atmosphere packaging system. This kind of modified atmosphere packaging technology (MAP) is so successful that meat can be cut and packaged several weeks before purchase and still remain fresh. Such systems typically utilize multiple layers of packaging. The outside layer of packaging is generally a rigid container with good barrier properties. The inner layer of packaging is an oxygen permeable film. To provide a modified atmosphere environment, the air- evacuated package is typically filled with a mixture of gases consisting of about 30 percent carbon dioxide (CO2) and 70 percent nitrogen (N2). Refilling the air- evacuated package with such a mixture of gases is believed to suppress the growth of anaerobic bacteria. The outer layer is peeled off just prior to presenting the consumer cut for sale at the supermarket. This allows the meat to rebloom to a bright red color. An excellent example of such an evacuation and refill MAP process is described in U.S. Patent No. 5,115,624 to Garwood. Vacuum packaging and refill MAP is very expensive for three reasons. First, the rigid part of the package is expensive. Second, processing speeds are slow due to the vacuum and refill steps. And third, the equipment to do these procedures is very complicated and expensive.
Another less expensive means of insuring a minimal level of oxygen in a meat package is to use a gas flush MAP process. The complicated steps of evacuating the package and refilling with the desired gas mixture are eliminated. The outer bag (a barrier layer), is simply flushed with the proper gas mixture as it is formed around the inner container. The flush process reduces the oxygen content of the package to about two percent. An oxygen scavenger is placed in the package to absorb additional oxygen just prior to or simultaneously with forming and flushing the outer bag. An excellent example of such a MAP system is described in the patent application entitled "Modified Atmosphere Package" filed on April 3, 1996, and given Serial No. 08/627,137. A critical feature of a gas flush MAP packaging system is the ability to keep meat looking fresh and palatable. Oxidized meat turns an undesirable brown color. Accordingly, as discussed, an oxygen scavenger is typically placed inside the meat package in order to absorb any residual oxygen within the package after gas flushing and sealing the package. It is critically important to quickly remove the oxygen from meat to prevent it from turning brown. Especially important in preventing the irreversible change from red to brown is the rate at which oxygen is scavenged. If oxygen is removed quickly, the packaged meat turns a purple red color. This purple red color quickly "blooms" to a bright red color upon removal of the outer layer of packaging.
Oxygen scavengers are increasingly being used in packaging systems in order to protect various products from the detrimental effects of oxygen exposure. Several oxygen scavengers utilize the oxidation of paniculate iron as a method to absorb oxygen. A small amount of water is essential for this reaction. In some instances, a water attracting agent such as silica gel can be used to attract water and at times to supply water in the packet initially. A major drawback to this technology is, however, the limited amount of water that can be supplied. Typically, a major portion of the water needed for the oxidation of paniculate iron is provided by the product and/or packaging environment being protected. This is oftentimes an inadequate amount to promote the efficient and expedient oxidation of iron. And as mentioned, the slower the rate of oxygen reduction, the more likely meat will turn irreversibly brown.
A need thus exists to accelerate the rate of oxygen scavengers, particularly in the confines of a modified atmosphere packaging system. Optimally, it would be desirable to lower the oxygen level to about 0.04 percent (400 PPM) within 90 minutes and to about zero within 24 hours. This need will be addressed by the present invention.
SUMMARY OF THE INVENTION
The present invention provides an iron-based oxygen scavenging packet which exhibits an increased rate of oxygen absorption especially in the confines of a concomitant meat packaging system. The invention specifically provides an oxygen scavenging packet which comprises an iron-based oxygen absorber and an oxygen uptake accelerator comprising water. The oxygen uptake accelerator accelerates the rate of oxygen uptake of the iron-based absorber. In a preferred embodiment, the invention provides an oxygen scavenging packet which additionally contains an oxygen uptake accelerator in the form of an aqueous solution of acetic acid. Optimally, the acetic acid solution is of approximately five percent strength. The present invention also provides a method of increasing the rate of oxygen absoφtion of an iron-based oxygen absorber by introducing an oxygen uptake accelerator into an oxygen scavenging packet containing an iron-based oxygen absorber. In preferred embodiments, an aqueous solution of acetic acid is introduced into the packet via injection, encapsulation in a rupturablc capsule, or by introduction by absoφtion through a wick. Optimally, the acetic acid solution that is introduced is of approximately five percent strength.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
FIG. 1 illustrates an oxygen scavenging packet in which the oxygen uptake accelerator is being introduced into the packet via a syringe.
FIGS. 2a and 2b, respectively, illustrate an oxygen scavenging packet containing a capsule which can be ruptured at an appropriate time to release the oxygen uptake accelerator and a packet containing a capsule being ruptured. FIGS. 3a and 3b, respectively, illustrate an oxygen scavenging packet including a protruding wick for absoφtion of the oxygen uptake accelerator into the packet and an oxygen scavenging packet in which the wick is being dipped into the oxygen scavenger accelerator. FIG. 4 is an isometric view of the oxygen scavenging packet of the instant invention inside a modified atmosphere packaging system.
FIG. 5 is a graph illustrating the rate of oxygen absoφtion when a dry oxygen scavenging packet is introduced into a quart sized container which also includes 0.5 ml of water. FIG. 6 is a graph illustrating the rate of oxygen absoφtion when an oxygen scavenging packet having 0.5 ml of water injected into the packet is introduced into a quart sized container. FIG. 7 is a graph illustrating the rate of oxygen absoφtion as a function of the amount of water injected into oxygen scavenging packets.
FIG. 8 illustrates the rate of oxygen absoφtion in the presence of varying amounts of CO2 utilizing an oxygen scavenging packet which has been injected with 0.6 ml of water.
FIG. 9 is a graph illustrating the rate of oxygen absoφtion as a function of the number of oxygen scavenging packets introduced into a one quart jar.
FIG. 10 is a graph showing the percent oxygen after 1 hour as a function of the amount of acetic acid (vinegar) injected into each of two oxygen scavenging packets. FIG. 1 1 is a graph showing the percent oxygen as a function of time and as a function of the material injected into the oxygen scavenging packets.
While the invention is susceptible to various modifications and alternative forms, certain specific embodiments thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular forms described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, FIGS. 1 through 3 (a and b) depict an oxygen scavenging packet having a liquid oxygen uptake accelerator present in some form within the packet.
Specifically, FIG. 1 depicts an oxygen scavenging packet 10 containing elemental iron 12 and in which an oxygen uptake accelerator 14 is introduced into the packet utilizing a syringe 16. Injection can be performed manually with a syringe and hand placement of the packet inside the package. Alternatively, the injection process can be automated by using a commercially available metering and dispensing pump such as the Luft Systematic model 45/50 and appropriate conveying equipment to position the packets for injection and then subsequently to place the packets into a package. FIG. 2a depicts an oxygen scavenging packet 20 containing elemental iron 22 and in which an oxygen uptake accelerator 24 is present inside a capsule 26. As FIG. 2b shows, the capsule 26 may be ruptured by mechanical force at an appropriate time in order to release the oxygen uptake accelerator 24. Optimally, the capsule should be ruptured immediately prior to or immediately after the sealing of the package in order to properly activate the iron-based scavenger for accelerated oxygen uptake. FIG. 3a depicts an iron-based oxygen scavenging packet 30 containing elemental iron (not specifically shown) and in which an oxygen uptake accelerator 32 can be introduced into the packet by absoφtion onto a wick 34 which protrudes from the packet. As FIG. 3b shows, the wick 34 dipped into the oxygen uptake accelerator 32. An appropriate amount of oxygen uptake accelerator 32 is absorbed through the wick 34 into the packet 30. Optimally, the dipping occurs immediately prior to the sealing of the package in order to properly activate the iron based scavenger for accelerated oxygen uptake.
Further information concerning the construction of the oxygen absorber packet preferred for use in the instant invention may be obtained from U.S. Patent No. 5,262,375 to McKedy, entitled "Oxygen Absorber." The preferred oxygen absorber packets are manufactured by Multiform Desiccants Incoφorated. However, other iron-based oxygen absorbers will work comparably well in the instant invention.
The instant invention particularly concerns an iron-based oxygen scavenging packet which contains an oxygen uptake accelerator consisting of water or an aqueous solution of some other substance dissolved in or mixed with water. The oxygen uptake accelerator accelerates the rate of oxygen uptake of the oxygen absorber. Water alone will activate and accelerate iron-based oxygen absorbers via the presence of hydronium ions in the water. However, dilute acid solutions are preferred oxygen uptake accelerators. Acids provide increased numbers of hydronium ions which increase the oxidation rate of iron by acting as electron acceptors. These electron acceptors facilitate the ionization of neutral iron. Once ionized, the iron readily reacts with the available oxygen and water to form a hydrated iron oxide. Other electron acceptors such as the positively charged ions making up salt solutions or metals such as copper also facilitate the ionization of neutral iron.
The preferred aqueous solution of the instant invention is an aqueous solution which contains approximately five percent acetic acid. The introduction of water or an aqueous solution of acid, salt or appropriate metal into the oxygen absorber packet of an iron-based oxygen absorber serves to activate and dramatically increase the rate of oxygen uptake of the iron inside the packet The paniculate iron in the packet, in effect, turns to rust as oxygen is absorbed from the atmosphere surrounding the packaged meat or other packaged food product As discussed, the water or aqueous solution enhances oxygen absoφtion by the iron by acting as an electron acceptor. A proposed mechanism for rust formation is as follows
Figure imgf000009_0001
(2) e + H3O+→ H + H2O
(3) 4H + O2 → 2H2O
(4) 4Fe2+ + O2 0?) + ( 12 + 2x)H2O → 2(Fe2O3 • -xH2O) (s) + 8 H3O+
In step (1) ferrous ions are produced by loss of electrons from the elemental paniculate iron in the packet. However, this process cannot go very far unless there is some way to get rid of the electrons which accumulate on the residual Fe One way to do this is by step (2) in which H3O+ ions either from the water or from acid substances in the water, pick up the electrons to form neutral H atoms Since Fe is known to be a good catalyst for hydrogenation reactions in general, it is believed that step (3) now occurs to use up the H atoms. In the meantime, the ferrous ion reacts with O2 gas by step (4) to form the rust and restore H30+ required for step (2). The net reaction, obtained by adding all four steps is
4Fe(j) + 3O2(g) + 2xH2O → 2(Fe2O3 • JCH2O)(.Ϊ)
Acid accelerates the reaction by providing excess hydronium ions (H3O+) and driving step 2 Therefore, the preferred embodiment of the present invention utilizes a dilute aqueous solution of acid. Such acid solutions should, of course, be compatible with food products and include, for instance, acetic acid and/or citric acid
Salt solutions also drive step (2) of the aforementioned reaction by providing an electron acceptor, thus they are suitable for use in the aqueous solution of the instant invention. Additionally, it has been found that adding copper to water and/or dilute aqueous solution of acid speeds the rate of oxygen absoφtion by the iron. It is believed that the copper induces a phenomena called electrolytic corrosion. Electrons flow from the iron to the copper, where their energy is lower. This removes the excess negative charge from the iron. In addition H atoms, which now form on the negative copper surface instead of the iron, detach themselves more readily from copper than from iron, thus accelerating step (3) of the aforementioned reaction.
The present invention also concerns a method of increasing the rate of oxygen absoφtion of an iron-based oxygen absorber by introducing an oxygen uptake accelerator comprising water or an aqueous solution into an oxygen scavenging packet containing an iron-based oxygen absorber. As discussed, and shown in FIGS. 1-3 (a and b), the aqueous solution can be introduced into the packet utilizing an injection type process. Alternatively, the solution can be included in the absorber packet in a separate capsule or compartment which can be ruptured at the time of sealing the meat package. Also, a wick could be included in, and protrude from, the packet such that the wick could be dipped in liquid just prior to sealing the meat package.
A preferred embodiment of the present invention involves the injection of an acetic acid solution of approximately five percent acidity into the MRM absorbers manufactured by Multiform Desiccants Incoφorated. This is done just prior to the placement of the absorber into a package. This can be done manually with a syringe and hand placement. Or, as discussed, the process can be automated by using a commercially available metering and dispensing pump such as the Luft Systematic model 45/50 and appropriate conveying equipment to position the packets for injection and then subsequently to place the packets into a package.
The following data, depicted in FIGS. 5-11 is specific to Multiform's MRM 100 scavenger. All of these experiments involve using these scavengers. The MRM 100 oxygen scavengers are specifically formulated to work in the presence of CO 2 and refrigeration.
FIGS. 5 and 6 illustrate that the oxygen uptake accelerator, in this case water, must be contained within the oxygen scavenging packet in order to increase the rate of oxygen absoφtion. Specifically, FIG. 5 shows the decrease in percent oxygen as a function of time when 0.5 ml of water is merely present in a quart-sized jar along with an oxygen scavenging packet. As shown in FIG. 5, at 40°F it takes approximately 30 hours for the percent oxygen to be reduced to approximately 0.5% (5,000 PPM) and more than 40 hours for the percent oxygen to be reduced to near 0.0% oxygen. By contrast, FIG. 6 shows the decrease in percent oxygen as a function of time when 0.5 ml of water is injected into an oxygen scavenging packet which is then placed in a quart-sized jar. At 40°F, it takes approximately 15 hours for the percent oxygen to be reduced to approximately 0.5% and about 20 hours for the percent oxygen to be reduced to near 0.0% oxygen. At 70°F, oxygen is scavenged much more quickly.
FIG. 7 shows that the oxygen scavenging rate is maximized when 0.6 ml of water is present in the oxygen scavenging packet. FIG. 8 shows that oxygen absoφtion appears to be independent of the amount of carbon dioxide in the container.
FIG. 9 shows that two oxygen scavenging packets absorb oxygen at nearly twice the rate of one packet.
As shown in FIG. 10, acetic acid, commonly known as vinegar acid, works particularly well in accelerating the rate of oxygen absoφtion of an MRM oxygen scavenger packet. Specifically, the injection of .5ml. of acetic acid into each of two absorber packets reduces the amount of oxygen in a quart jar to approximately .1% O2 (1000 PPM) in one hour. As shown in FIG. 12, the percent O2 is reduced to approximately .04% O2 (400 PPM) in about ninety minutes when .5ml. of acetic acid is injected into each of two MRM 100 scavenger packets. Two conclusions can be drawn from the data in FIGS. 10 and 11. First, injected acetic acid seems to work better than plain water in increasing the rate of oxygen absoφtion of an absorber packet. Second, from FIG. 10, .5ml. acetic acid appears to work particularly well in increasing the rate and total amount of oxygen absoφtion. In the experiments resulting in the data in FIGS. 10 and 11 , the starting level of oxygen in the jars was 2.0%, simulating the amount of oxygen which would be present after the gas flush step of a gas flush MAP process. Also, the experiments were performed under refrigeration.
The present invention is particularly useful when used in a modified atmosphere packaging (MAP) process for fresh meats. The MAP process is a gas flush process that initially flushes the package to an oxygen atmosphere of about two percent or less. The oxygen scavenging packet of the instant invention is utilized to additionally reduce the oxygen level of the package to 400 PPM (0.04%) or less within ninety minutes.
A brief description of the typical modified atmosphere package will follow. This description is not meant to be limiting, but instead is provided merely to elucidate one particular use for the instant invention.
FIG. 4 depicts a modified atmosphere package 40 including an outer container 42 and an inner container 44. The inner container 44 includes a conventional semirigid plastic tray 46 thermoformed from a sheet of polymeric material which is substantially permeable to oxygen. Exemplary polymers which may be used to form the non-barrier tray 46 include polystyrene foam, cellulose pulp, polyethylene, polypropylene, etc. In a preferred embodiment, the polymeric sheet used to form the tray 46 is substantially composed of polystyrene foam and has a thickness ranging from about 100 mils to about 300 mils. The use of a common polystyrene foam tray 46 is desirable because it has a high consumer acceptance. The inner container 44 further includes a stretch film wrapping or cover 48 substantially composed of a polymeric material, such as polyvinyl chloride (PVC), which is substantially permeable to oxygen. In a preferred embodiment, the stretch film used to form the cover 48 contains additives which allow the film to cling to itself and has a thickness ranging from about 0.5 mil to about 1.5 mils. One preferred stretch film is Resinite™ meat film commercially available from Borden Packaging and Industrial Products of North Andover, Massachusetts.
A food item such as a retail cut of raw meat 50 is located inside the inner container 44. Prior to fully wrapping the tray 46 with the cover 48, the partially formed inner container 44 may be flushed with an appropriate mixture of gases, typically a mixture of about 30 percent carbon dioxide and about 70 percent nitrogen, to lower the oxygen level in the inner container 44 to about 1.5 to 5.0 percent. The foregoing mixture of gases displaces the oxygen within the inner container 44 during the flushing operation. After flushing the inner container 44, the tray 46 is manually or automatically wrapped with the cover 48. The cover 48 is wrapped over the retail cut of raw meat 50 and about the bottom of the tray 46. The free ends of the cover 48 are overlapped along the underside of the bottom wall of the tray 46, and, due to the cling characteristic inherent in the cover 48, these overlapping free ends cling to one another to hold the cover 48 in place. If desired, the overwrapped tray 46, i.e., the inner container 44, may be run over a hot plate to thermally fuse the free ends of the cover 48 to one another and thereby prevent these free ends from potentially unraveling. The outer container 42 is preferably a flexible polymeric bag composed of a single or multilayer plastics material which is substantially impermeable to oxygen. The outer container 42 may, for example, include an oriented polypropylene (OPP) core coated with an oxygen barrier coating such as polyvinylidene chloride and further laminated with a layer of sealant material such as polyethylene to facilitate heat sealing. In a preferred embodiment, the outer container 42 is composed of a multilayer barrier film commercially available as product no. 325C44-0EX861D from PrintPack, Inc. of Atlanta, Georgia. The co-extruded film has a thickness ranging from about 2 mils to about 6 mils. Prior to sealing the peripheral edges of the outer container 42, the inner container 44 is placed within the outer container 42. Also, the outer container 42 is flushed with an appropriate mixture of gases, typically about 30 percent carbon dioxide and about 70 percent nitrogen, to lower the oxygen level in the outer container 42 to about 0.05 to 5.0 percent or 500 to 50,000 parts per million (PPM). Prior to or simultaneously with flushing the outer container 42, but still prior to sealing the outer container 42, the oxygen scavenging packet 52 is placed in the outer container 42 external to the sealed inner container 44. The outer container 42 is then sealed.
After a time period of about ninety minutes, the oxygen scavenging packet 52 lowers the oxygen level in the bag from its initial level of oxygen to less than about 0.04 percent or 400 PPM and most preferably to about zero percent. The oxygen uptake accelerator contained within the oxygen scavenging packet 52 is responsible for this fast rate of oxygen absoφtion. The oxygen scavenger 52 also absorbs any oxygen which might permeate into the outer container 42 from the ambient environment. In FIGS. 1 through 4, the oxygen scavenger 10, 20, 30, and 52 respectively, is illustrated as a packet or label which is inserted into the outer container 42 prior to sealing the outer container 42. Alternatively, an oxygen scavenging material may be added to the polymer or polymers used to form the outer container 42 so that the oxygen scavenging material is integrated into the outer container 42 itself.
The retail cut of raw meat 50 within the package 40 takes on a puφle-red color when the oxygen is removed from the interior of the package 40. The meat-filled modified atmosphere package 40 may now be stored in a refrigeration unit for several weeks prior to being offered for sale at a grocery store. A short time (e.g., less than one hour) prior to being displayed at the grocery store, the inner container 44 is removed from the outer container 42 to allow oxygen from the ambient environment to permeate the non-barrier tray 46 and non-barrier cover 48. The puφle-red color of the raw meat 56 quickly changes or "blooms" to a generally acceptable bright red color when the raw meat 56 is oxygenated by exposure to air.
While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.

Claims

WHAT IS CLAIMED IS:
1. An oxygen scavenging packet, comprising: an iron based oxygen absorber; and an oxygen uptake accelerator comprising water.
2. The oxygen scavenging packet of claim 1 , wherein said oxygen uptake accelerator further comprises an acid.
3. The oxygen scavenging packet of claim 2, wherein said acid is citric acid.
4. The oxygen scavenging packet of claim 2, wherein said oxygen uptake accelerator is acetic acid.
5. The oxygen scavenging packet of claim 4, wherein said oxygen uptake accelerator comprises approximately five percent acetic acid in water.
6. The oxygen scavenging packet of claim 1 , wherein said oxygen uptake accelerator comprises a salt solution.
7. The oxygen scavenging packet of claim 6, wherein said salt solution is selected from the group consisting of a solution of NaCl, a solution of CaCl2, and a solution of MgCl2.
8. The oxygen scavenging packet of claim 1, wherein said packet further comprises copper.
9. The oxygen scavenging packet of claim 1, wherein between .5 and .6 miUiliters of said oxygen uptake accelerator is present in said oxygen scavenging packet.
10. The oxygen scavenging packet of claim 5, wherein between .5 and .6 miUiliters of five percent acetic acid in water is present in said oxygen scavenging packet.
1 1. A method of increasing the rate of oxygen absoφtion of an iron based oxygen absorber comprising the steps of: a) providing an oxygen scavenging packet containing an iron based oxygen absorber; and b) introducing an oxygen uptake accelerator comprising water.
12. The method of claim 1 1 , wherein said step of introducing said oxygen uptake accelerator into said packet includes injecting said oxygen uptake accelerator into said packet with a syringe.
13. The method of claim 1 1 , wherein said step of introducing said oxygen uptake accelerator into said packet includes placing in said packet a capsule capable of being ruptured at an appropriate time to release said oxygen uptake accelerator.
14. The method of claim 1 1 , wherein said step of introducing said oxygen uptake accelerator into said packet includes placing a wick into said packet and dipping said wick into an oxygen uptake accelerator such that it absorbs an appropriate amount of said oxygen uptake accelerator.
15. The method of claim 1 1, wherein said oxygen uptake accelerator comprises a substance selected from the group consisting of water or aqueous solutions of acetic acid, citric acid, sodium chloride, calcium chloride, magnesium chloride and copper.
16. The method of claim 1 1 , wherein said oxygen uptake accelerator comprises between .5 and .6 miUiliters of aqueous acetic acid.
17. An oxygen scavenging packet, comprising: an iron based oxygen absorber; and an oxygen uptake accelerator comprising a substance selected from the group consisting of water or aqueous solutions of acetic acid, citric acid, sodium chloride, calcium chloride, magnesium chloride and copper.
18. The oxygen scavenging packet of claim 17, wherein said oxygen uptake accelerator is an aqueous solution containing approximately five percent acetic acid.
PCT/US1997/013048 1996-08-08 1997-08-06 Oxygen scavenger accelerator WO1998006281A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU38933/97A AU3893397A (en) 1996-08-08 1997-08-06 Oxygen scavenger accelerator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US70064496A 1996-08-08 1996-08-08
US08/700,644 1996-08-08

Publications (2)

Publication Number Publication Date
WO1998006281A1 true WO1998006281A1 (en) 1998-02-19
WO1998006281A9 WO1998006281A9 (en) 1998-08-27

Family

ID=24814332

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/013048 WO1998006281A1 (en) 1996-08-08 1997-08-06 Oxygen scavenger accelerator

Country Status (2)

Country Link
AU (1) AU3893397A (en)
WO (1) WO1998006281A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000028839A1 (en) * 1998-11-13 2000-05-25 Pactiv Corporation Oxygen scavenger accelerator
FR2909261A1 (en) * 2006-12-04 2008-06-06 Atmosphere Controle Incorporating moisture in adhesive labels, comprises drilling a lower face of the labels through a silicon carrier band and then introducing a predetermined quantity of water in a hole created by drilling using a dosing device
WO2010085927A1 (en) * 2009-01-31 2010-08-05 Moessmer Raimund Composition and system for detecting oxygen and biological ligands

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1556853A (en) * 1977-09-23 1979-11-28 Merck Patent Gmbh Oxygen-absorbing agents
US4510162A (en) * 1983-03-07 1985-04-09 Creative Research & Development, Inc. Composition for absorbing oxygen and carrier therefore
US4762722A (en) * 1984-04-16 1988-08-09 Mitsubishi Gas Chemical Company, Inc. Sealed package of raw meat or fish and method of preserving raw meat or fish

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1556853A (en) * 1977-09-23 1979-11-28 Merck Patent Gmbh Oxygen-absorbing agents
US4510162A (en) * 1983-03-07 1985-04-09 Creative Research & Development, Inc. Composition for absorbing oxygen and carrier therefore
US4762722A (en) * 1984-04-16 1988-08-09 Mitsubishi Gas Chemical Company, Inc. Sealed package of raw meat or fish and method of preserving raw meat or fish

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000028839A1 (en) * 1998-11-13 2000-05-25 Pactiv Corporation Oxygen scavenger accelerator
FR2909261A1 (en) * 2006-12-04 2008-06-06 Atmosphere Controle Incorporating moisture in adhesive labels, comprises drilling a lower face of the labels through a silicon carrier band and then introducing a predetermined quantity of water in a hole created by drilling using a dosing device
WO2010085927A1 (en) * 2009-01-31 2010-08-05 Moessmer Raimund Composition and system for detecting oxygen and biological ligands

Also Published As

Publication number Publication date
AU3893397A (en) 1998-03-06

Similar Documents

Publication Publication Date Title
US5928560A (en) Oxygen scavenger accelerator
US7147799B2 (en) Methods of using an oxygen scavenger
US5811142A (en) Modified atmosphere package for cut of raw meat
US6447826B1 (en) Packaging for meat and foodstuff
AU717804B2 (en) Chemical treatment and packaging system to improve the appearance and shelf life of fresh pork
US6395195B1 (en) Oxygen scavenger accelerator
US20130062242A1 (en) Package for preserving respiring produce and apparatus for making the same
US20200315194A1 (en) Zero-OxTech® Process for preservation of enzymes in the protein muscle and its applications
US5985342A (en) Chemical treatment and packaging system to improve the appearance and shelf life of fresh pork
WO1998006281A1 (en) Oxygen scavenger accelerator
WO1998006281A9 (en) Oxygen scavenger accelerator
EP1242560A1 (en) Rapid oxygen absorption by using activators
WO2000028839A1 (en) Oxygen scavenger accelerator
US20060147586A1 (en) Method for extending shelf-life and prevention of discoloration of meat
US11849745B2 (en) Method and apparatus for extending shelf-life of meat and poultry
MXPA99010456A (en) Oxygen scavenger accelerator
US20240108035A1 (en) Apparatus for extending shelf-life of meat and poultry and method of using the same
CA2250887C (en) Modified atmosphere package
JPH03151824A (en) Freshness preservation for roe

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE HU IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG US UZ VN AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH KE LS MW SD SZ UG ZW AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ

121 Ep: the epo has been informed by wipo that ep was designated in this application
CFP Corrected version of a pamphlet front page
CR1 Correction of entry in section i

Free format text: PAT. BUL. 07/98 UNDER (81) DELETE "US"

COP Corrected version of pamphlet

Free format text: PAGES 1/6-6/6, DRAWINGS, REPLACED BY NEW PAGES 1/6-6/6; DUE TO LATE TRANSMITTAL BY THE RECEIVING OFFICE

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 98509748

Format of ref document f/p: F

NENP Non-entry into the national phase

Ref country code: CA