US3346398A - Method of preserving perishable material - Google Patents
Method of preserving perishable material Download PDFInfo
- Publication number
- US3346398A US3346398A US337039A US33703964A US3346398A US 3346398 A US3346398 A US 3346398A US 337039 A US337039 A US 337039A US 33703964 A US33703964 A US 33703964A US 3346398 A US3346398 A US 3346398A
- Authority
- US
- United States
- Prior art keywords
- propylene oxide
- container
- sterilizing
- oxide
- ethylene oxide
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 title claims description 42
- 238000000034 method Methods 0.000 title claims description 34
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 claims description 74
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims description 37
- 239000000203 mixture Substances 0.000 claims description 31
- 230000001954 sterilising effect Effects 0.000 claims description 24
- 229910000323 aluminium silicate Inorganic materials 0.000 claims description 14
- 241001465754 Metazoa Species 0.000 claims description 11
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- 235000013311 vegetables Nutrition 0.000 claims description 9
- 238000004321 preservation Methods 0.000 claims description 7
- 238000007789 sealing Methods 0.000 claims description 6
- 241000894006 Bacteria Species 0.000 claims description 5
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 38
- 239000002808 molecular sieve Substances 0.000 description 37
- 235000013305 food Nutrition 0.000 description 22
- 150000002924 oxiranes Chemical class 0.000 description 18
- 239000003206 sterilizing agent Substances 0.000 description 17
- -1 polyethylene Polymers 0.000 description 13
- 239000000834 fixative Substances 0.000 description 12
- 241000233866 Fungi Species 0.000 description 11
- 239000004698 Polyethylene Substances 0.000 description 11
- 229920000573 polyethylene Polymers 0.000 description 11
- 235000008429 bread Nutrition 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 239000011148 porous material Substances 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 125000002947 alkylene group Chemical group 0.000 description 7
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical group C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 239000005022 packaging material Substances 0.000 description 6
- 239000002775 capsule Substances 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 239000005416 organic matter Substances 0.000 description 5
- 238000004806 packaging method and process Methods 0.000 description 5
- 239000000123 paper Substances 0.000 description 5
- 229920003023 plastic Polymers 0.000 description 5
- 239000004033 plastic Substances 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 4
- 230000000844 anti-bacterial effect Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 235000013372 meat Nutrition 0.000 description 4
- 239000008188 pellet Substances 0.000 description 4
- 235000000832 Ayote Nutrition 0.000 description 3
- 235000009854 Cucurbita moschata Nutrition 0.000 description 3
- 240000001980 Cucurbita pepo Species 0.000 description 3
- 235000009804 Cucurbita pepo subsp pepo Nutrition 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000000020 Nitrocellulose Substances 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- FJWGYAHXMCUOOM-QHOUIDNNSA-N [(2s,3r,4s,5r,6r)-2-[(2r,3r,4s,5r,6s)-4,5-dinitrooxy-2-(nitrooxymethyl)-6-[(2r,3r,4s,5r,6s)-4,5,6-trinitrooxy-2-(nitrooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-3,5-dinitrooxy-6-(nitrooxymethyl)oxan-4-yl] nitrate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O)O[C@H]1[C@@H]([C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@@H](CO[N+]([O-])=O)O1)O[N+]([O-])=O)CO[N+](=O)[O-])[C@@H]1[C@@H](CO[N+]([O-])=O)O[C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O FJWGYAHXMCUOOM-QHOUIDNNSA-N 0.000 description 3
- 229920002301 cellulose acetate Polymers 0.000 description 3
- 235000013351 cheese Nutrition 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000013270 controlled release Methods 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000002360 explosive Substances 0.000 description 3
- 230000000855 fungicidal effect Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000010348 incorporation Methods 0.000 description 3
- 229920001220 nitrocellulos Polymers 0.000 description 3
- 235000015136 pumpkin Nutrition 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 235000007688 Lycopersicon esculentum Nutrition 0.000 description 2
- 229930182555 Penicillin Natural products 0.000 description 2
- JGSARLDLIJGVTE-MBNYWOFBSA-N Penicillin G Chemical compound N([C@H]1[C@H]2SC([C@@H](N2C1=O)C(O)=O)(C)C)C(=O)CC1=CC=CC=C1 JGSARLDLIJGVTE-MBNYWOFBSA-N 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 2
- 240000003768 Solanum lycopersicum Species 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000003899 bactericide agent Substances 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 238000006703 hydration reaction Methods 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 231100000252 nontoxic Toxicity 0.000 description 2
- 230000003000 nontoxic effect Effects 0.000 description 2
- 229940049954 penicillin Drugs 0.000 description 2
- 229920001223 polyethylene glycol Polymers 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 241001398967 Colonia Species 0.000 description 1
- 239000001856 Ethyl cellulose Substances 0.000 description 1
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 1
- RMOUBSOVHSONPZ-UHFFFAOYSA-N Isopropyl formate Chemical compound CC(C)OC=O RMOUBSOVHSONPZ-UHFFFAOYSA-N 0.000 description 1
- 240000002129 Malva sylvestris Species 0.000 description 1
- 235000006770 Malva sylvestris Nutrition 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229920001800 Shellac Polymers 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- JYIBXUUINYLWLR-UHFFFAOYSA-N aluminum;calcium;potassium;silicon;sodium;trihydrate Chemical compound O.O.O.[Na].[Al].[Si].[K].[Ca] JYIBXUUINYLWLR-UHFFFAOYSA-N 0.000 description 1
- RMKJAAPVONZTMN-UHFFFAOYSA-N aluminum;dihydroxy(oxo)silane;sodium Chemical compound [Na].[Al].O[Si](O)=O.O[Si](O)=O.O[Si](O)=O.O[Si](O)=O.O[Si](O)=O RMKJAAPVONZTMN-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- UNYSKUBLZGJSLV-UHFFFAOYSA-L calcium;1,3,5,2,4,6$l^{2}-trioxadisilaluminane 2,4-dioxide;dihydroxide;hexahydrate Chemical compound O.O.O.O.O.O.[OH-].[OH-].[Ca+2].O=[Si]1O[Al]O[Si](=O)O1.O=[Si]1O[Al]O[Si](=O)O1 UNYSKUBLZGJSLV-UHFFFAOYSA-L 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000011111 cardboard Substances 0.000 description 1
- 229910052676 chabazite Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910001603 clinoptilolite Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 229910052675 erionite Inorganic materials 0.000 description 1
- 229920001249 ethyl cellulose Polymers 0.000 description 1
- 235000019325 ethyl cellulose Nutrition 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000012013 faujasite Substances 0.000 description 1
- 229910001657 ferrierite group Inorganic materials 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 238000009459 flexible packaging Methods 0.000 description 1
- 238000009920 food preservation Methods 0.000 description 1
- 239000000417 fungicide Substances 0.000 description 1
- 229910001683 gmelinite Inorganic materials 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 230000036512 infertility Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 229910052680 mordenite Inorganic materials 0.000 description 1
- 238000012858 packaging process Methods 0.000 description 1
- 235000021485 packed food Nutrition 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 150000003839 salts Chemical group 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- ZLGIYFNHBLSMPS-ATJNOEHPSA-N shellac Chemical compound OCCCCCC(O)C(O)CCCCCCCC(O)=O.C1C23[C@H](C(O)=O)CCC2[C@](C)(CO)[C@@H]1C(C(O)=O)=C[C@@H]3O ZLGIYFNHBLSMPS-ATJNOEHPSA-N 0.000 description 1
- 239000004208 shellac Substances 0.000 description 1
- 229940113147 shellac Drugs 0.000 description 1
- 235000013874 shellac Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000009461 vacuum packaging Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
- B65D81/24—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, 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
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/34—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
- A23L3/3409—Preservation 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
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, 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
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/34—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
- A23L3/3409—Preservation 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
- A23L3/3445—Preservation 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 comprising other gases in addition to CO2, N2, O2 or H2O
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
- B65B25/00—Packaging other articles presenting special problems
- B65B25/001—Packaging other articles presenting special problems of foodstuffs, combined with their conservation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/26—Aluminium-containing silicates, i.e. silico-aluminates
- C01B33/28—Base exchange silicates, e.g. zeolites
- C01B33/2807—Zeolitic silicoaluminates with a tridimensional crystalline structure possessing molecular sieve properties; Isomorphous compounds wherein a part of the aluminium ore of the silicon present may be replaced by other elements such as gallium, germanium, phosphorus; Preparation of zeolitic molecular sieves from molecular sieves of another type or from preformed reacting mixtures
Definitions
- the present invention relates to the preservation of perishable materials containing animal or vegetable matter which is subject to spoilage caused by bacteria or molds.
- the invention is primarily concerned with the preservation of such materials by maintaining them in a bactericidal and fungicidal atmosphere.
- ethylene oxide and propylene oxide As between ethylene oxide and propylene oxide, it has been found that the latter is generally more satisfactory as a sterilizing agent, for a number of reasons. For example, upon reaction with Water or moisture in the presence of food, propylene oxide hydrolyzes to form propylene glycol which is substantially non-toxic when consumed in amounts of the magnitude that would be found on or in food packaged in an atmosphere of propylene oxide. On the other hand, ethylene oxide hydrolyzes to produce ethylene glycol which is considerably more toxic. Also, while both propylene oxide and ethylene oxide are explosive when mixed with air, propylene oxide-air mixtures are explosive over a much narrower or more restricted composition range than are mixtures of air and ethylene oxide. Another important advantage of propylene oxide is that it is a liquid under normal conditions of temperature and pressure and therefore is easier to handle than ethylene oxide which is normally a gas.
- an object of the present invention to provide safe, convenient and economical methods and compositions for employing ethylene oxide and/or propylene oxide as sterilizing agents for organic matter.
- a further object of the invention is to provide methods and compositions for sterilizing organic matter by the use of ethylene oxide and/ or propylene oxide which are safe, require no special receptacles and do not call for expensive or elaborate equipment to maintain special conditions of temperature or pressure during their use.
- a further object of the present invention is to provide a safe and efiicient method for using ethylene oxide and propylene oxide as sterilizing agents without serious danger of explosion.
- a further object of the present invention is to provide compositions comprising ethylene oxide and/or propylene oxide and methods employing such compositions which enable animal and vegetable matter to be preserved from spoilage safely and conveniently and over extended periods of time.
- Another object of the invention is to provide a method and compositions for preserving food by maintaining the food in an atmosphere comprising ethylene oxide and/or propylene oxide vapors.
- An additional object of the present invention is to provide a method and composition for packaging food, especially food for distribution to consumers so that a sterilizing atmosphere of propylene oxide may be maintained in the package over an extended period of time.
- FIG. 1 is a side cross-sectional view of a container including a sterilizing .composition in accordance with the present invention
- FIG. 2 is a side cross-sectional view of a container comprising another composition in accordance with the present invention.
- FIG. 3 is a side cross-sectional view of a portion of a sheet of packaging material coated with a sterilizing composition of the present invention
- FIG. 4 is a side cross-sectional view of a portion of a sheet of packaging material comprising a sterilizing composition of the present invention
- 7 FIG. is a side cross-sectional view of a package made from the material of FIG. 3 or FIG. 4.
- the present invention generally comprises the preservation of animal and vegetable matter from spoilage by exposing such materials to an atmosphere of ethylene oxide and/or propylene oxide vapors and by providing for the relatively slow and controlled release of the ethylene oxide and/or propylene oxide vapors into the atmosphere surrounding the material to be protected.
- compositions are provided which are capable of slowly releasing or diffusing sterilizing ethylene oxide and/or propylene oxide vapors over extended periods of time so that the sterilizing atmosphere may be maintained and continuously regenerated in circumstances where the food or other materials is temporarily exposed to the atmosphere, where the container is not air tight or where the container is constructed at least in part from materials pervious to air, moisture or propylene oxide vapors.
- the invention also comprises compositions containing ethylene oxide and/or propylene oxide which are safe to use, which gradually release sterilizing vapors and which are so economical that they are entirely disposable.
- animal or vegetable matter which is to be preserved is placed in a container together with an amount of molecular sieve having absorbed therein ethylene oxide and/ or propylene oxide as a sterilizing agent.
- molecular sieves absorb moisture in preference to alkylene oxides so that as moisture is absorbed from the food or from the atmosphere surrounding the food or other organic matter in the container, alkylene oxide is gradually released from the molecular sieve into the atmosphere to maintain the contents in a sterilizing condition. The moisture, when absorbed in the sieve, results in desorption of the ethylene oxide or propylene oxide.
- the moisture may be taken from the contents of the container, such as a foodstufi, or from the atmosphere present when the container is closed or admitted when the container is temporarily opened.
- the molecular sieve function as a reservoir for the epoxide sterilizing agent, but it also simultaneously provides a dehydrating function which further contributes to the inhibition of mold growth and other processes of spoilage.
- the slow diffusion or exudation of ethylene oxide or propylene oxide vapors from the molecular sieves has the added very important advantage that diffusion takes place more rapidly in high moisture containing atmospheres. Since it is under conditions of high relative humidity that the danger of spoilage is most acute, the fact that the release of the sterilizing agent takes place more rapidly under such conditions is an especially important aspect of the invention.
- the release of absorbed sterilizing agents from other adsorbents would not ordinarily be responsive to changes in relative humidity.
- Another important embodiment of the present inven tion comprises the introduction of ethylene oxide or propylene oxide liquid or gas into closed tubes, packets, capsules or the like which are pervious to propylene oxide vapors and the insertion of such epoxide containers into a package or receptacle containing material to be preserved against spoilage.
- This method enables the diffusion of the epoxide vapors to be controlled so that the sterilizing agent is continuously but gradually diffused through the wall of the capsule into the atmosphere surrounding the food or similar material.
- a preferred method for carrying out this embodiment of the invention comprises introducing liquid ethylene oxide and/or propylene oxide into a sealed tube or capsule of a plastic which is permeable by the alkylene oxide vapors.
- polyethylene is a very suitable ma terial for use in forming the capsules or tube to receive the sterilizing agent.
- Another very important embodiment of the invention comprises the incorporation of liquid propylene oxide into a fixative which enables ethylene oxide and/ or propylene oxide vapors to be slowly and gradually exuded or diffused.
- the preferred method for accomplishing this embodiment of the invention comprises dissolving propylene oxide in a film-forming fixative. This solution may then be used as a coating or impregnant on various materials used for the packaging of food or similar commodities.
- fixatives are polyethylene glycol polymers having molecular weights ranging from about 200 to about 600 or higher, cellulose acetate, cellulose nitrate, shellac, etc.
- FIG. 1 The use of molecular sieves containing absorbed propylene oxide to sterilize foodstuffs or the like is illustrated in FIG. 1 of the drawing.
- container 10 is filled with a material 11 which is to be preserved against spoilage.
- One or more pellets of molecular sieve 12 containing absorbed ethylene oxide or propylene oxide are introduced into the container to furnish the desired sterilizing atmosphere.
- the contents 11 of the container 10 may be any material of animal or vegetable origin which may be attacked by bacteria or mold.
- the container 10 may be of any size and construction.
- it may be the familiar small volume metal can or jar employed in sales to the consumer and having a volume of from a few ounces up to one or two quarts.
- the container may be a drum of considerable capacity used in commercial operations and having a volume of many gallons.
- the container may be constructed of metal, plastic, paper and combinations of these and other conventional packaging materials.
- the molecular sieve pellets 12 may be segregated from the contents 11 of the container by a perforated diaphragm 13 which freely permits transfer of moisture and the ethylene oxide or propylene oxide vapors between the molecular sieve compartment 14 and the other compartment 15 in which material subject to spoilage is located.
- contents of the container to be preserved are materials for internal human or animal consumption
- propylene oxide is used as the sterilizing agent since its residue is substantially non-toxic. Otherwise, ethylene and/ or propylene oxide may be used.
- the amount of molecular sieve and alkylene oxide composition may be varied in accordance with the size of the container and its intended or usual method of use.
- the container is the type which is sealed air tight and then is ordinarily opened, emptied, and disposed of, then only enough of the sterilizing composition need be included to maintain sterility within the container prior to opening.
- the container is of a type which is ordinarily opened, partially emptied and reclosed, more of the molecular sieve-propylene oxide composition may be desirable, so that the sterilizing atmosphere may be regenerated a number of times as the container is opened and reclosed.
- Molecular sieves of the type used in this invention are crystalline metal aluminosilicate materials of the following general formula:
- n is the valence of the metal cation M
- M ordinarily is Na or K but may be other cations substituted by exchange
- Y is the number of moles of alumina
- Z is the number of moles of Water of hydration.
- the crystalline metal aluminosilicates Upon removal of the water of hydration by heating, the crystalline metal aluminosilicates become highly porous and are characterized by a series of surface cavities and internal pores which form an interconnecting network of passageways within the crystal. Due to the crystalline nature of such materials, the diameters of the surface cavities and of the internal pores is substantially constant and is of molecular magnitude. For this reason, the crystalline metal aluminosilicates have found wide use in the separation of materials according to molecular size or configuration, hence the name molecular sieves.
- Molecular sieves or crystalline aluminosilicates are also sometimes referred to as crystalline zeolites and are of bot-h natural and synthetic origin.
- Synthetic materials include, for example, synthetic faujasite.
- Natural crystalline aluminosilicates exhibiting molecular sieve activity include for example, analcite, paulingite, ptilolite, clinoptilolite, ferrierite, chabazite, gmelinite, levynite, erionite and mordenite.
- 13X molecular sieve is a sieve of the X type which is believed to have pores having diameters of about 13 angstroms.
- a molecular sieve is a synthetic crystalline aluminosilicate of the A type having pores the diameters of which are approximately 5 angstroms.
- sterilizing compositions are prepared by heating a molecular sieve material, preferably in the form of compacted pellets, spheres or the like to remove moisture and then causing Sliced Tomatoes.
- the dried sieve to be impregnated with ethylene oxide or propylene oxide.
- the impregnation may be accomplished by immersing crystals or pelleted crystals of the molecular sieve in liquid ethylene oxide or propylene oxide or by placing the pellets or crystals in a closed vessel containing the oxide vapors.
- 123 tablets of 13X molecular sieve having a thickness of A and a diameter of were baked overnight in an oven at a temperature of 500 F. to drive off absorbed moisture.
- the dried tablets were then quickly transferred to a porous bag and the bag was suspended in a closed glass container above the level of liquid propylene oxide placed in the bottom of the container.
- the molecular sieve was thus exposed for a period of 5 days during which time the temperature was maintained at about 45 F. Upon Weighing, it was found that the molecular sieve had adsorbed about 20% by weight of propylene oxide into its pores.
- the molecular sieve-propylene oxide composition is quite effective in preventing or reducing the spoilage of various foodstuffs.
- pumpkin meat in Bag No. 2 showed some softening and the presence of a considerable amount of liquid, but the fungus growth was not as extensive as in Bag No. l.
- the pumpkin meat in Bag No. 3 was in good condition.
- Example 4 Sliced fresh tomatoes were placed in two glass jars. In one of the jars was placed one tablet of a 13X molecular sieve saturated with about 20% by weight of propylene oxide. The tablet was A" in diameter and A" thick. Both jars were then sealed.
- Example 5 The same procedure was then followed with sliced bologna.
- Example 6 The procedure was then followed with pieces of cheese cake.
- a slice of bread and two drops of water were placed in a polyethylene bag and the bag was folded closed.
- a second slice ofbread, two drops of water and a tube of polyethylene containing cc. of propylene oxide were then placed in a second polyethylene bag which was likewise folded closed.
- Example 8 p A slice of bread inoculated with a penicillin'fungus was placed in a first polyethylene bag and the bag was folded closed. A second slice of bread inoculated with the same amount and type of penicillin fungus as the first slice was placed in a second polyethylene bag with a polyethylene tube containing 12 cc. of propylene oxide. The bag was then folded closed.
- the container preferably is polyethylene or other plastic which is pervious to the alkylene oxide vapors and which enables the vapors to dififuse through the wall of the tube into the atmosphere surrounding the food 21.
- Tube 22 may be dropped into the container with the food or may be adhesively attached to the bottom of container 24 or to its side walls or may be placed in a pocket, clamp or recess in a wall of the container or in the closure.
- the plastic used to form the tube may be of a Water soluble or disintegrable nature and may be edible as well, so that if the food -placed in the container contains substantial amounts of water, the tube will disintegrate after release of the propylene oxide and will leave no undesirable residue.
- the third major embodiment of the present invention generally comprises dissolving or dispersing ethylene oxide and/or propylene oxide in a fixative which gradually releases propylene oxide vapors to the atmosphere.
- the fixative is preferably a film-forming substance which can be used to coat or impregnate packaging materials. If at least part of an interior wall of a package made from such material carries such a coating, propylene oxide vapors will gradually be released to v the atmosphere within the package.
- a specific example of material prepared in accordance with this invention may comprise a conventional paper-foil laminate of the type widely used for packaging foods.
- the laminate comprises a layer of paper 31 adhesively bonded to a foil of aluminum 32 or other impermeable material.
- the other surface of the paper is coated with a film 33 of a fixative containing propylene oxide.
- the film 33 may, for example, comprise -a concentrated solution of ethylene oxide and/ or propylene oxide in a polyethylene glycol polymer having a molecular weight of about 200.
- the filmforming fixative solution containing ethylene oxide and/ or propylene oxide may be applied as an interlayer between an impermeable foil and a vapor permeable layer.
- the laminated sheet material shown in cross-section comprises a vapor permeable layer 41, such as polyethylene, cellulose acetate or the like, a vapor impermeable layer 43, such as aluminum foil or heavy waxed paper, and an interlayer 42 which is a film of fixative containing ethylene or propylene oxide.
- a vapor permeable layer 41 such as polyethylene, cellulose acetate or the like
- a vapor impermeable layer 43 such as aluminum foil or heavy waxed paper
- an interlayer 42 which is a film of fixative containing ethylene or propylene oxide.
- materials of the type shown in FIGS. 3 and 4 may be used to form a package 51 for foods 52, such as sliced meats, cheeses, or the like by wrapping the material around the article to be packaged and crimp sealing as at 53.
- the material is employed so that the impermeable foil layer 32 or 43 is on the outside so that the propylene oxide vapors may difiuse and fill the inside of the package 51.
- any rigid or flexible packaging or wrapping material whether of paper, cardboard, wood, plastic, or metal, or of either single ply or laminated construction, may be coated over part or all of one or both surfaces so that in packages or containers formed from the material, the ethylene oxide or propylene oxide sterilizing agent in the fixative is released within the container.
- a method for the preservation of perishable material which comprises placing in a container which is impermeable to air animal or vegetable matter subject to spoilage by bacteria or molds and a sterilizing composition comprising a crystalline porous metal aluminosilic-ate and an alkylene oxide selected from the group consisting of ethylene oxide and propylene oxide absorbed within the pores of said aluminosilicate, closing said container using an airtight sealing means and maintaining said matter in a sterilizing atmosphere of said alkylene oxide vaporsfor an extended period of time by the slow and controlled release of'said vapors from said sterilizing composition into the atmosphere surrounding the matter to be protected in response to changes in relative humidity within said container.
- a method in accordance with claim l wherein said sterilizing composition is segregated from said matter subor animal consumption and said sterilizing composition is propylene oxide absorbed in said aluminosilicate.
- a method for the preservation of perishable material which comprises placing in a glass container animal or vegetable foodstufis for human consumption which are subject to spoilage by bacteria or molds and a porous crystalline aluminosilicate 13X molecular sieve having propylene oxide absorbed within its pores in an amount of about 20% by weight of said sieve, sealing said glass container using an airtight sealing means and maintaining said foodstuffs in a sterilizing atmosphere of said propylene oxide vapors for an extended period of time by the slow and controlled release of said vapors from said propylene oxide-containing molecular sieve int-o the atmosphere sur- 15 rounding the foodstufis to be protected in response to changes in relative humidity within said container.
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Description
Oct. 10, 1967 w. o. TUNDERMANN ET AL 3,346,398
METHOD OF PRESERVING PERISHABLE MATERIAL Filed Jan. 10, 1964 IN VENTORS w o. TUNDERMANN S.D. FRIEDMAN United States Patent Office 3,346,398 Patented Oct. 10, 1967 3,346,398 METHOD OF PRESER G PERISHABLE MATERIAL Werner O. Tundermann, Colonia, and Stuart D. Friedman, Bound Brook, NJ., assignors to Colgate-Palmolive Company, New York, N.Y., a corporation of Delaware Filed Jan. 10, 1964, Ser. No. 337,039 Claims. (Cl. 99--171) The present invention relates to the preservation of perishable materials containing animal or vegetable matter which is subject to spoilage caused by bacteria or molds. The invention is primarily concerned with the preservation of such materials by maintaining them in a bactericidal and fungicidal atmosphere.
Extensive work has already been done on various methods and materials to be used in preventing the spoilage of perishable organic matter. One general approach to this problem, extensively employed in the field of food preservation, has been to package the particular food commodity in an evacuated container. By the removal of air and moisture, the processes of deterioration are greatly retarded. Other methods involve heating the material to sterilizing temperatures prior to packing or storage. Another approach to the problem, sometimes used in conjunction with the vacuum packing or heat sterilizing methods previously noted, has been to flood the container with a sterilizing agent prior to closing of the package, so that a sterilizing atmosphere is maintained until the package is opened;
In processes of the latter type, considerable attention has been directed to the use of epoxides, such as ethylene oxide and propylene oxide, as sterilizing agents. Although the epoxides have been found to exhibit excellent bactericidal and fungicidal activity, certain serious disadvantages have sharply limited their usefulness.
Among the more serious drawbacks involved in the use of epoxides as sterilizing agents is the explosive character of epoxide-air mixtures. This problem presents a serious safety problem in large scale commercial packaging processes employing such materials and makes the epoxides generally unsuited to home use, i.e., use in packages which are distributed directly to the consumer and are taken into the home, as opposed to bulk commercial packaging.
Another disadvantage in the use of the epoxides has been their tendency to quickly volatilize and escape from the storage container. When sealed containers into which epoxide sterilizing agents have been introduced are opened, the epoxide vapors escape almost instantaneously. The epoxide vapors also escape very rapidly from containers which are not hermetically sealed and they may even escape rapidly from many types of sealed containers, since a number of conventional packaging materials are readily permeated by the epoxide vapors.
In order to overcome this problem, attempts have been made to utilize the epoxides in the form of solutions in solvents, such as carbon dioxide, isopropyl formate and ethylene dichloride which tend to lower the vapor pressure of the epoxides. However, such epoxide solutions have not been entirely successful due to cost, adulteration of the flavor, color or texture of foods contacted by the solutions, the production of undesirable residues and the like. In addition, the lowering of the vapor pressure in solutions of this type is only suflicient ao enable the epoxide to be handled as a liquid and introduced into the package. Thereafter, the epoxide vaporizes rapidly and is subject to the same drawbacks noted in the previous paragraph.
As between ethylene oxide and propylene oxide, it has been found that the latter is generally more satisfactory as a sterilizing agent, for a number of reasons. For example, upon reaction with Water or moisture in the presence of food, propylene oxide hydrolyzes to form propylene glycol which is substantially non-toxic when consumed in amounts of the magnitude that would be found on or in food packaged in an atmosphere of propylene oxide. On the other hand, ethylene oxide hydrolyzes to produce ethylene glycol which is considerably more toxic. Also, while both propylene oxide and ethylene oxide are explosive when mixed with air, propylene oxide-air mixtures are explosive over a much narrower or more restricted composition range than are mixtures of air and ethylene oxide. Another important advantage of propylene oxide is that it is a liquid under normal conditions of temperature and pressure and therefore is easier to handle than ethylene oxide which is normally a gas.
No entirely satisfactory method for using ethylene oxide as a bactericide for organic matter is presently available. Notwithstanding the advantages of propylene oxide over ethylene oxide, no fully satisfactory method for safely and efficiently utilizing propylene oxide as a bactericide and fungicide for the preservation of foodstuffs and other animal and vegetable matter has as yet been developed. Especially lacking has been a suitable method for utilizing ethylene oxide or propylene oxide to sterilize packaged foods which are sold to the consumer and which may not be sealed against the atmosphere or may be opened and reclosed a number of times before the contents of the package are exhausted.
A satisfactory method for the use of ethylene oxide or propylene oxide as sterilizing agents in commercial bulk or retail scale packaging should be convenient, economical and safe. Conventional methods have required special containers or filling apparatus which are both complicated to use and are expensive. Other common techniques have used the epoxides in vapor form and introduce a considerable explosion hazard.
It is, therefore, an object of the present invention to provide safe, convenient and economical methods and compositions for employing ethylene oxide and/or propylene oxide as sterilizing agents for organic matter.
A further object of the invention is to provide methods and compositions for sterilizing organic matter by the use of ethylene oxide and/ or propylene oxide which are safe, require no special receptacles and do not call for expensive or elaborate equipment to maintain special conditions of temperature or pressure during their use.
A further object of the present invention is to provide a safe and efiicient method for using ethylene oxide and propylene oxide as sterilizing agents without serious danger of explosion.
A further object of the present invention is to provide compositions comprising ethylene oxide and/or propylene oxide and methods employing such compositions which enable animal and vegetable matter to be preserved from spoilage safely and conveniently and over extended periods of time.
Another object of the invention is to provide a method and compositions for preserving food by maintaining the food in an atmosphere comprising ethylene oxide and/or propylene oxide vapors.
An additional object of the present invention is to provide a method and composition for packaging food, especially food for distribution to consumers so that a sterilizing atmosphere of propylene oxide may be maintained in the package over an extended period of time.
The manner in which the foregoing objects and many other highly desirable objects are realized will be apparent in the light of the following detailed description of the invention and by reference to the accompanying drawings.
In the drawings:
FIG. 1 is a side cross-sectional view of a container including a sterilizing .composition in accordance with the present invention;
FIG. 2 is a side cross-sectional view of a container comprising another composition in accordance with the present invention;
FIG. 3 is a side cross-sectional view of a portion of a sheet of packaging material coated with a sterilizing composition of the present invention;
FIG. 4 is a side cross-sectional view of a portion of a sheet of packaging material comprising a sterilizing composition of the present invention; and 7 FIG. is a side cross-sectional view of a package made from the material of FIG. 3 or FIG. 4.
The present invention generally comprises the preservation of animal and vegetable matter from spoilage by exposing such materials to an atmosphere of ethylene oxide and/or propylene oxide vapors and by providing for the relatively slow and controlled release of the ethylene oxide and/or propylene oxide vapors into the atmosphere surrounding the material to be protected.
In accordance with the invention, compositions are provided which are capable of slowly releasing or diffusing sterilizing ethylene oxide and/or propylene oxide vapors over extended periods of time so that the sterilizing atmosphere may be maintained and continuously regenerated in circumstances where the food or other materials is temporarily exposed to the atmosphere, where the container is not air tight or where the container is constructed at least in part from materials pervious to air, moisture or propylene oxide vapors.
The invention also comprises compositions containing ethylene oxide and/or propylene oxide which are safe to use, which gradually release sterilizing vapors and which are so economical that they are entirely disposable.
According to one principal embodiment of the present invention, animal or vegetable matter which is to be preserved is placed in a container together with an amount of molecular sieve having absorbed therein ethylene oxide and/ or propylene oxide as a sterilizing agent. It has been found that molecular sieves absorb moisture in preference to alkylene oxides so that as moisture is absorbed from the food or from the atmosphere surrounding the food or other organic matter in the container, alkylene oxide is gradually released from the molecular sieve into the atmosphere to maintain the contents in a sterilizing condition. The moisture, when absorbed in the sieve, results in desorption of the ethylene oxide or propylene oxide. The moisture may be taken from the contents of the container, such as a foodstufi, or from the atmosphere present when the container is closed or admitted when the container is temporarily opened. Thus, not only does the molecular sieve function as a reservoir for the epoxide sterilizing agent, but it also simultaneously provides a dehydrating function which further contributes to the inhibition of mold growth and other processes of spoilage. I The slow diffusion or exudation of ethylene oxide or propylene oxide vapors from the molecular sieves has the added very important advantage that diffusion takes place more rapidly in high moisture containing atmospheres. Since it is under conditions of high relative humidity that the danger of spoilage is most acute, the fact that the release of the sterilizing agent takes place more rapidly under such conditions is an especially important aspect of the invention. The release of absorbed sterilizing agents from other adsorbents would not ordinarily be responsive to changes in relative humidity.
Another important embodiment of the present inven tion comprises the introduction of ethylene oxide or propylene oxide liquid or gas into closed tubes, packets, capsules or the like which are pervious to propylene oxide vapors and the insertion of such epoxide containers into a package or receptacle containing material to be preserved against spoilage. This method enables the diffusion of the epoxide vapors to be controlled so that the sterilizing agent is continuously but gradually diffused through the wall of the capsule into the atmosphere surrounding the food or similar material.
A preferred method for carrying out this embodiment of the invention comprises introducing liquid ethylene oxide and/or propylene oxide into a sealed tube or capsule of a plastic which is permeable by the alkylene oxide vapors. For example, polyethylene is a very suitable ma terial for use in forming the capsules or tube to receive the sterilizing agent.
It will be understood that other materials capable of holding liquid or vaporized ethylene oxide and/ or propylene oxide and of diffusing their vapors may also be used in place of the polyethylene. In addition, the wall thickness of the particular material and the rate at which it permits propylene oxide vapors to pass may be selected so as to best suit the particular circumstances. Other filmforming materials through which ethylene and propylene oxides Will diffuse and which are therefore useful in the present invention include ethyl cellulose, rubber hydrov chloride, cellulose acetate, cellulose nitrate and polypropylene.
Another very important embodiment of the invention comprises the incorporation of liquid propylene oxide into a fixative which enables ethylene oxide and/ or propylene oxide vapors to be slowly and gradually exuded or diffused. The preferred method for accomplishing this embodiment of the invention comprises dissolving propylene oxide in a film-forming fixative. This solution may then be used as a coating or impregnant on various materials used for the packaging of food or similar commodities. Examples of such fixatives are polyethylene glycol polymers having molecular weights ranging from about 200 to about 600 or higher, cellulose acetate, cellulose nitrate, shellac, etc.
Although the incorporation of ethylene or propylene oxide in capsules permeable to their vapors or in fixative coatings does not have the self-regulatory feature of molecular sieves containing absorbed oxides, their slow but constant release of the oxide acts effectively over a period of time and they avoid the need for using high temperatures or low pressures and are much safer to handle than prior compositions and methods.
The use of molecular sieves containing absorbed propylene oxide to sterilize foodstuffs or the like is illustrated in FIG. 1 of the drawing. As will be seen by reference to this figure, container 10 is filled with a material 11 which is to be preserved against spoilage. One or more pellets of molecular sieve 12 containing absorbed ethylene oxide or propylene oxide are introduced into the container to furnish the desired sterilizing atmosphere.
It will be understood that the contents 11 of the container 10 may be any material of animal or vegetable origin which may be attacked by bacteria or mold. Likewise, the container 10 may be of any size and construction. For example, it may be the familiar small volume metal can or jar employed in sales to the consumer and having a volume of from a few ounces up to one or two quarts. On the other hand, the container may be a drum of considerable capacity used in commercial operations and having a volume of many gallons. Similarly, the container may be constructed of metal, plastic, paper and combinations of these and other conventional packaging materials.
If desired, the molecular sieve pellets 12 may be segregated from the contents 11 of the container by a perforated diaphragm 13 which freely permits transfer of moisture and the ethylene oxide or propylene oxide vapors between the molecular sieve compartment 14 and the other compartment 15 in which material subject to spoilage is located.
Where the contents of the container to be preserved are materials for internal human or animal consumption,
propylene oxide is used as the sterilizing agent since its residue is substantially non-toxic. Otherwise, ethylene and/ or propylene oxide may be used.
It will also be understood that the amount of molecular sieve and alkylene oxide composition may be varied in accordance with the size of the container and its intended or usual method of use. For example, if the container is the type which is sealed air tight and then is ordinarily opened, emptied, and disposed of, then only enough of the sterilizing composition need be included to maintain sterility within the container prior to opening. However, if the container is of a type which is ordinarily opened, partially emptied and reclosed, more of the molecular sieve-propylene oxide composition may be desirable, so that the sterilizing atmosphere may be regenerated a number of times as the container is opened and reclosed.
Molecular sieves of the type used in this invention are crystalline metal aluminosilicate materials of the following general formula:
Mg o YA1203 in the salt form, where n is the valence of the metal cation M, M ordinarily is Na or K but may be other cations substituted by exchange, Y is the number of moles of alumina and Z is the number of moles of Water of hydration.
Upon removal of the water of hydration by heating, the crystalline metal aluminosilicates become highly porous and are characterized by a series of surface cavities and internal pores which form an interconnecting network of passageways within the crystal. Due to the crystalline nature of such materials, the diameters of the surface cavities and of the internal pores is substantially constant and is of molecular magnitude. For this reason, the crystalline metal aluminosilicates have found wide use in the separation of materials according to molecular size or configuration, hence the name molecular sieves.
Molecular sieves or crystalline aluminosilicates are also sometimes referred to as crystalline zeolites and are of bot-h natural and synthetic origin. Synthetic materials include, for example, synthetic faujasite. Natural crystalline aluminosilicates exhibiting molecular sieve activity include for example, analcite, paulingite, ptilolite, clinoptilolite, ferrierite, chabazite, gmelinite, levynite, erionite and mordenite.
Since not all of the natural crystalline aluminosilicates are available in abundance, considerable attention has been directed'to the production of synthetic equivalents. A number of these are available on a commercial scale and are designated as X molecular sieve, Y molecular sieve, and A molecular sieve. Other molecular sieves which have been synthesized include B, F, G, H, K-G, I, L, M, K-M, Q, R, S, T, U and Z zeolites.
While it is contemplated that any molecular sieve which absorbs water with preference to ethylene oxide or propylene oxide will be suitablefor use in accordance with the present invention, it has been found that the Linde 13X molecular sieve is especially satisfactory. The synthesis and composition of the X molecular sieves are described in US. Patent No. 2,882,244, Milton, issued Apr. 14, 1959. Y molecular sieve is described in Belgian Patent 577,642, and A molecular sieve is described in U.S. 2,882,243, Milton and 2,982,612, Barrer et al.
The numerical prefix in the designation or identification of various molecular sieves indicates the approximate pore size in angstroms. For example, 13X molecular sieve is a sieve of the X type which is believed to have pores having diameters of about 13 angstroms. On the other hand, a A molecular sieve is a synthetic crystalline aluminosilicate of the A type having pores the diameters of which are approximately 5 angstroms.
In accordance with the present invention, sterilizing compositions are prepared by heating a molecular sieve material, preferably in the form of compacted pellets, spheres or the like to remove moisture and then causing Sliced Tomatoes.--
6 the dried sieve to be impregnated with ethylene oxide or propylene oxide. The impregnation may be accomplished by immersing crystals or pelleted crystals of the molecular sieve in liquid ethylene oxide or propylene oxide or by placing the pellets or crystals in a closed vessel containing the oxide vapors.
As an example of the later method, 123 tablets of 13X molecular sieve having a thickness of A and a diameter of were baked overnight in an oven at a temperature of 500 F. to drive off absorbed moisture. The dried tablets were then quickly transferred to a porous bag and the bag was suspended in a closed glass container above the level of liquid propylene oxide placed in the bottom of the container. The molecular sieve was thus exposed for a period of 5 days during which time the temperature was maintained at about 45 F. Upon Weighing, it was found that the molecular sieve had adsorbed about 20% by weight of propylene oxide into its pores.
As demonstrated in the following examples, the molecular sieve-propylene oxide composition is quite effective in preventing or reducing the spoilage of various foodstuffs.
Examples 1-3 Grams Bag No. 2 1.6 Bag No. 3 3.2
After four days, the pumpkin meat in Bag No. 1 was observed to be covered with heavy black fungus. The
pumpkin meat in Bag No. 2 showed some softening and the presence of a considerable amount of liquid, but the fungus growth was not as extensive as in Bag No. l. The pumpkin meat in Bag No. 3 was in good condition.
Example 4 Sliced fresh tomatoes were placed in two glass jars. In one of the jars was placed one tablet of a 13X molecular sieve saturated with about 20% by weight of propylene oxide. The tablet was A" in diameter and A" thick. Both jars were then sealed.
Example 5 The same procedure was then followed with sliced bologna.
Example 6 The procedure was then followed with pieces of cheese cake.
After one Week, observation of the food in the jars showed the following results:
Protected by Molecular Control Sieve Propylene Oxide Slices covered with white N o evidence of fungus. fungus.
Sliced Bo1ogna. Slices showed spots of D0.
both White and black fungus.
Cheese Cake Cake showed several Do.
spots of blue fungus.
It will be seen from the above examples that the incorporation of molecular sieve material saturated with propylene oxide into food packages greatly extends the materials may be protected from spoilage. When other forms of propylene oxide sterilizing gas are incorporated into food containers, such as liquid propylene oxide, solutions of propylene oxide or the like, the gas volatilizes quite rapidly and is substantially lost almost immediately upon opening of the 'packageor exposure of the propylene oxide to the atmos- "phere. According to the present invention, however, it
A slice of bread and two drops of water were placed in a polyethylene bag and the bag was folded closed. A second slice ofbread, two drops of water and a tube of polyethylene containing cc. of propylene oxide were then placed in a second polyethylene bag which was likewise folded closed.
After twelve days, it' was observed that fungus growth had begun on the slice placed in the first bag, but that no fungus growth had commenced on the slice of bread .placed in the bag with the polyethylene tube containing propylene oxide. Upon observation after several months, no fungus growth was found to have commenced on the slice of bread in the bag containing the tube of propylene oxide.
Example 8 p A slice of bread inoculated with a penicillin'fungus was placed in a first polyethylene bag and the bag was folded closed. A second slice of bread inoculated with the same amount and type of penicillin fungus as the first slice was placed in a second polyethylene bag with a polyethylene tube containing 12 cc. of propylene oxide. The bag was then folded closed.
After five days, extensive mold was observed on the slice of bread placed in the first bag. The slice of bread placed in the second bag with the tube of propylene oxide was free from mold. Again, as in Example 7, observation after the elapse of several months showed no mold to be present on the slice of bread in the second bag.
According to the second major embodiment of the invention, as illustrated in FIG. 2 of the drawing, food 21 and a tube 22 containing ethylene oxide and/ or propylene oxide 23 are placed into anouter container 24 and the container is then closed The tube preferably is polyethylene or other plastic which is pervious to the alkylene oxide vapors and which enables the vapors to dififuse through the wall of the tube into the atmosphere surrounding the food 21.
The third major embodiment of the present invention, as previously described, generally comprises dissolving or dispersing ethylene oxide and/or propylene oxide in a fixative which gradually releases propylene oxide vapors to the atmosphere. The fixative is preferably a film-forming substance which can be used to coat or impregnate packaging materials. If at least part of an interior wall of a package made from such material carries such a coating, propylene oxide vapors will gradually be released to v the atmosphere within the package.
As illustrated in FIG. 3 of the drawing, a specific example of material prepared in accordance with this invention may comprise a conventional paper-foil laminate of the type widely used for packaging foods. The laminate comprises a layer of paper 31 adhesively bonded to a foil of aluminum 32 or other impermeable material. The other surface of the paper is coated with a film 33 of a fixative containing propylene oxide. The film 33 may, for example, comprise -a concentrated solution of ethylene oxide and/ or propylene oxide in a polyethylene glycol polymer having a molecular weight of about 200.
As a modification of this general embodiment, the filmforming fixative solution containing ethylene oxide and/ or propylene oxide may be applied as an interlayer between an impermeable foil and a vapor permeable layer.
Referring to FIG. 4 of the drawing, the laminated sheet material shown in cross-section comprises a vapor permeable layer 41, such as polyethylene, cellulose acetate or the like, a vapor impermeable layer 43, such as aluminum foil or heavy waxed paper, and an interlayer 42 which is a film of fixative containing ethylene or propylene oxide. As the sterilizing agent is gradually released from the fixative film, such as cellulose nitrate, it diffuses through the permeable layer 41.
As further illustrated in FIG. 5, materials of the type shown in FIGS. 3 and 4 may be used to form a package 51 for foods 52, such as sliced meats, cheeses, or the like by wrapping the material around the article to be packaged and crimp sealing as at 53. In each case, the material is employed so that the impermeable foil layer 32 or 43 is on the outside so that the propylene oxide vapors may difiuse and fill the inside of the package 51.
Other methods for forming and sealing packages made from materials coated or impregnated with the fixativepropylene oxide composition will be readily apparent.
It will also be seen that the relative amounts of fixative and propylene oxide or ethylene oxide in the present compositions may be varied and that the compositions may be applied to a great variety of packaging materials with the same beneficial results. For example, any rigid or flexible packaging or wrapping material, whether of paper, cardboard, wood, plastic, or metal, or of either single ply or laminated construction, may be coated over part or all of one or both surfaces so that in packages or containers formed from the material, the ethylene oxide or propylene oxide sterilizing agent in the fixative is released within the container. I
While the present invention has been fully described and illustrated with reference to certain preferred embodiments, it will be apparent to those skilled in the art that various modifications may be made without departing from the spirit of the invention or the scope of the following claims.
What is claimed is:
1. A method for the preservation of perishable material which comprises placing in a container which is impermeable to air animal or vegetable matter subject to spoilage by bacteria or molds and a sterilizing composition comprising a crystalline porous metal aluminosilic-ate and an alkylene oxide selected from the group consisting of ethylene oxide and propylene oxide absorbed within the pores of said aluminosilicate, closing said container using an airtight sealing means and maintaining said matter in a sterilizing atmosphere of said alkylene oxide vaporsfor an extended period of time by the slow and controlled release of'said vapors from said sterilizing composition into the atmosphere surrounding the matter to be protected in response to changes in relative humidity within said container.
2. A method in accordance with claim 1 wherein said aluminosilicate is a synthetic molecular sieve.
3. A method in accordance with claim lwherein said sterilizing composition is segregated from said matter subor animal consumption and said sterilizing composition is propylene oxide absorbed in said aluminosilicate.
5. A method for the preservation of perishable material which comprises placing in a glass container animal or vegetable foodstufis for human consumption which are subject to spoilage by bacteria or molds and a porous crystalline aluminosilicate 13X molecular sieve having propylene oxide absorbed within its pores in an amount of about 20% by weight of said sieve, sealing said glass container using an airtight sealing means and maintaining said foodstuffs in a sterilizing atmosphere of said propylene oxide vapors for an extended period of time by the slow and controlled release of said vapors from said propylene oxide-containing molecular sieve int-o the atmosphere sur- 15 rounding the foodstufis to be protected in response to changes in relative humidity within said container.
References Cited UNITED STATES PATENTS 1,765,920 6/1930 Humpert.
2,370,768 3/1945 Baerwald 99171 2,979,410 4/ 1961 Parlour 99171 3,033,642 5/1962 Bukata 23-112 X 3,062,659 11/1962 Hyson et al.
3,183,057 5/1965 Mark-s et a1. 2158 3,234,028 2/1966 Dunham et al. 99-l50 X OTHER REFERENCES Chemical Loaded Molecular Sieves, Aug. 3, 1959, published by Linde Company, Division of Union Carbide Corporation, pp. 1 to 6, inclusive.
HYMAN LORD, Primary Examiner. A. LOUIS MONACELL, Examiner.
Claims (1)
1. A METHOD FOR THE PRESERVATION OF PERISHABLE MATERIAL WHICH COMPRISES PLACING IN A CONTAINER WHICH IS IMPERMEABLE TO AIR ANIMAL OR VEGETABLE MATTER SUBJECT TO SPOILAGE BY BACTERIA OR MOLDS AND A STERILIZING COMPOSITION COMPRISING A CRYSTALLINE POROUS METAL ALUMINOSILICATE AND AN ALKYLENE OXIDE SELECTED FROM THE GROUP CONSISTING OF ETHYLENE OXIDE AND PROPYLENE OXIDE ABSORBED WITHIN THE PORES OF SAID ALUMINOSILICATE, CLOSING SAID CONTAINER USING AN AIRTIGHT SEALING MEANS AND MAINTAINING SAID MATTER IN
Priority Applications (14)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US337039A US3346398A (en) | 1964-01-10 | 1964-01-10 | Method of preserving perishable material |
SE14389/64A SE321846B (en) | 1964-01-10 | 1964-11-27 | |
IT26166/64A IT950503B (en) | 1964-01-10 | 1964-12-07 | METHOD AND COMPOSITION FOR STORING PERISHABLE ORGANIC PRODUCTS LI |
DE19641492598 DE1492598A1 (en) | 1964-01-10 | 1964-12-11 | Process and means for preserving perishable animal and vegetable substances |
ES0307015A ES307015A1 (en) | 1964-01-10 | 1964-12-11 | A method for preserving or preserving animal or vegetable substances that are subject to the effects of decomposition. (Machine-translation by Google Translate, not legally binding) |
CH1619564A CH458903A (en) | 1964-01-10 | 1964-12-15 | Process for the preservation of perishable animal and vegetable substances |
AT1059564A AT266567B (en) | 1964-01-10 | 1964-12-15 | Process for preserving animal and vegetable products |
GB51618/64A GB1035720A (en) | 1964-01-10 | 1964-12-18 | Preservation of perishable materials |
FR529A FR1458943A (en) | 1964-01-10 | 1964-12-31 | Method for preserving perishable materials and composition for its implementation |
BE657875D BE657875A (en) | 1964-01-10 | 1965-01-04 | |
NL6500073A NL6500073A (en) | 1964-01-10 | 1965-01-06 | |
DK12465AA DK126295B (en) | 1964-01-10 | 1965-01-11 | Method for preserving perishable animal or vegetable material. |
BE691324D BE691324A (en) | 1964-01-10 | 1966-12-16 | |
MY196813A MY6800013A (en) | 1964-01-10 | 1968-12-31 | Preservation of perishale materials |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US337039A US3346398A (en) | 1964-01-10 | 1964-01-10 | Method of preserving perishable material |
Publications (1)
Publication Number | Publication Date |
---|---|
US3346398A true US3346398A (en) | 1967-10-10 |
Family
ID=23318841
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US337039A Expired - Lifetime US3346398A (en) | 1964-01-10 | 1964-01-10 | Method of preserving perishable material |
Country Status (13)
Country | Link |
---|---|
US (1) | US3346398A (en) |
AT (1) | AT266567B (en) |
BE (1) | BE657875A (en) |
CH (1) | CH458903A (en) |
DE (1) | DE1492598A1 (en) |
DK (1) | DK126295B (en) |
ES (1) | ES307015A1 (en) |
FR (1) | FR1458943A (en) |
GB (1) | GB1035720A (en) |
IT (1) | IT950503B (en) |
MY (1) | MY6800013A (en) |
NL (1) | NL6500073A (en) |
SE (1) | SE321846B (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3476506A (en) * | 1965-04-14 | 1969-11-04 | Andersen Prod H W | Sterilization apparatus |
US3533806A (en) * | 1967-09-26 | 1970-10-13 | Thomas H Papworth | Grain preservative method |
US3559562A (en) * | 1969-06-06 | 1971-02-02 | Boise Cascade Corp | Sulfur dioxide-releasing device |
US3630665A (en) * | 1966-06-30 | 1971-12-28 | Andersen Prod H W | Method of sterilization |
US4550026A (en) * | 1983-02-15 | 1985-10-29 | Yosuke Akiba | Method for preserving food using a preservative gas atmosphere |
US4664922A (en) * | 1983-05-18 | 1987-05-12 | Leon Jean G | Package for preserving food by generating a modified gas atmosphere |
US4897273A (en) * | 1986-08-08 | 1990-01-30 | Mitsubishi Gas Chemical Co., Inc. | Package with freshness keeping agent sack |
WO1996010905A1 (en) * | 1994-10-06 | 1996-04-18 | Keith Charles Tipler | Substance releasing materials |
US5688545A (en) * | 1996-03-04 | 1997-11-18 | Kraft Jacobs Suchard Limited | Coffee package with enhanced aroma impact |
US5955004A (en) * | 1996-03-22 | 1999-09-21 | Moreno; Alfonso De Sande | Composition of a product to preserve perishable foodstuffs |
US20030056469A1 (en) * | 2001-09-27 | 2003-03-27 | Robert Armbruster | Bale enveloping material containing a preservative |
US20040018278A1 (en) * | 2002-07-25 | 2004-01-29 | Popplewell Lewis Michael | Packaging containing fragrance |
US20040018293A1 (en) * | 2002-07-25 | 2004-01-29 | Popplewell Lewis Michael | Packaging containing fragrance |
US20070059414A1 (en) * | 2005-09-13 | 2007-03-15 | Novak John S | Method and Process of Using Controlled Gas Environments to Inhibit Microbial Growth |
US20100044296A1 (en) * | 2005-11-28 | 2010-02-25 | G3 Enterprises | Highly Selective Molecular Confinement for the Prevention and Removal of Taint in Foods and Beverages |
WO2018014022A1 (en) * | 2016-07-15 | 2018-01-18 | University Of Florida Research Foundation, Incorporated | Permeation device for beneficial supplementation to gaseous atmospheres in enclosed volumes |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5470457A (en) * | 1977-11-07 | 1979-06-06 | Takeda Chemical Industries Ltd | Preservation of fresheness of fruit and vegetables |
SE438425B (en) * | 1977-11-21 | 1985-04-22 | Toppan Printing Co Ltd | FRESH PRESERVANT AGENTS FOR VEGETABLES AND FRUITS, CONSISTING OF A PARTICULAR COMPOSITION CONTAINING AT LEAST TWO ADSORBENTS |
JPS56142167A (en) * | 1980-04-04 | 1981-11-06 | Freunt Ind Co Ltd | Tool for preserving food |
NZ213989A (en) * | 1984-10-30 | 1988-07-28 | Seiwa Tech Lab | Preserving biodegradable products using hinokitiol(2-hydroxy-4-(1-methylethyl)-2,4,6-cycloheptatrien-1-one) and packaging materials therefor |
US4802574A (en) * | 1987-12-01 | 1989-02-07 | Yosuke Akiba | Absorbent for a gas preservative atomosphere |
GB2216769A (en) * | 1988-03-31 | 1989-10-18 | Takashi Sawada | Method and container for packaging and preserving fresh fruit |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1765920A (en) * | 1927-06-17 | 1930-06-24 | Staniolfabrik Burgdorf A G | Production of acid-resisting wrapping material |
US2370768A (en) * | 1944-10-02 | 1945-03-06 | Rosenberg Bros & Co | Food preservation method |
US2979410A (en) * | 1957-05-13 | 1961-04-11 | Tee Pak Inc | Food package and packaging film therefor |
US3033642A (en) * | 1959-08-31 | 1962-05-08 | Union Carbide Corp | Method of removing hydrogen and oxygen from gaseous mixtures |
US3062659A (en) * | 1960-07-06 | 1962-11-06 | Du Pont | Process for retarding the ripening of fruit |
US3183057A (en) * | 1958-11-03 | 1965-05-11 | Wallace & Tiernan Inc | Products and procedures for effecting treatiment with chlorinous gas |
US3234028A (en) * | 1961-09-20 | 1966-02-08 | Union Carbide Corp | Process for banana ripening |
-
1964
- 1964-01-10 US US337039A patent/US3346398A/en not_active Expired - Lifetime
- 1964-11-27 SE SE14389/64A patent/SE321846B/xx unknown
- 1964-12-07 IT IT26166/64A patent/IT950503B/en active
- 1964-12-11 ES ES0307015A patent/ES307015A1/en not_active Expired
- 1964-12-11 DE DE19641492598 patent/DE1492598A1/en active Pending
- 1964-12-15 CH CH1619564A patent/CH458903A/en unknown
- 1964-12-15 AT AT1059564A patent/AT266567B/en active
- 1964-12-18 GB GB51618/64A patent/GB1035720A/en not_active Expired
- 1964-12-31 FR FR529A patent/FR1458943A/en not_active Expired
-
1965
- 1965-01-04 BE BE657875D patent/BE657875A/xx unknown
- 1965-01-06 NL NL6500073A patent/NL6500073A/xx unknown
- 1965-01-11 DK DK12465AA patent/DK126295B/en unknown
-
1968
- 1968-12-31 MY MY196813A patent/MY6800013A/en unknown
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1765920A (en) * | 1927-06-17 | 1930-06-24 | Staniolfabrik Burgdorf A G | Production of acid-resisting wrapping material |
US2370768A (en) * | 1944-10-02 | 1945-03-06 | Rosenberg Bros & Co | Food preservation method |
US2979410A (en) * | 1957-05-13 | 1961-04-11 | Tee Pak Inc | Food package and packaging film therefor |
US3183057A (en) * | 1958-11-03 | 1965-05-11 | Wallace & Tiernan Inc | Products and procedures for effecting treatiment with chlorinous gas |
US3033642A (en) * | 1959-08-31 | 1962-05-08 | Union Carbide Corp | Method of removing hydrogen and oxygen from gaseous mixtures |
US3062659A (en) * | 1960-07-06 | 1962-11-06 | Du Pont | Process for retarding the ripening of fruit |
US3234028A (en) * | 1961-09-20 | 1966-02-08 | Union Carbide Corp | Process for banana ripening |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3476506A (en) * | 1965-04-14 | 1969-11-04 | Andersen Prod H W | Sterilization apparatus |
US3630665A (en) * | 1966-06-30 | 1971-12-28 | Andersen Prod H W | Method of sterilization |
US3533806A (en) * | 1967-09-26 | 1970-10-13 | Thomas H Papworth | Grain preservative method |
US3559562A (en) * | 1969-06-06 | 1971-02-02 | Boise Cascade Corp | Sulfur dioxide-releasing device |
US4550026A (en) * | 1983-02-15 | 1985-10-29 | Yosuke Akiba | Method for preserving food using a preservative gas atmosphere |
US4664922A (en) * | 1983-05-18 | 1987-05-12 | Leon Jean G | Package for preserving food by generating a modified gas atmosphere |
US4897273A (en) * | 1986-08-08 | 1990-01-30 | Mitsubishi Gas Chemical Co., Inc. | Package with freshness keeping agent sack |
US6429156B1 (en) * | 1994-10-06 | 2002-08-06 | Keith Charles Tipler | Substance releasing materials |
WO1996010905A1 (en) * | 1994-10-06 | 1996-04-18 | Keith Charles Tipler | Substance releasing materials |
US5688545A (en) * | 1996-03-04 | 1997-11-18 | Kraft Jacobs Suchard Limited | Coffee package with enhanced aroma impact |
US5955004A (en) * | 1996-03-22 | 1999-09-21 | Moreno; Alfonso De Sande | Composition of a product to preserve perishable foodstuffs |
US20030056469A1 (en) * | 2001-09-27 | 2003-03-27 | Robert Armbruster | Bale enveloping material containing a preservative |
US20040018278A1 (en) * | 2002-07-25 | 2004-01-29 | Popplewell Lewis Michael | Packaging containing fragrance |
US20040018293A1 (en) * | 2002-07-25 | 2004-01-29 | Popplewell Lewis Michael | Packaging containing fragrance |
US20070059414A1 (en) * | 2005-09-13 | 2007-03-15 | Novak John S | Method and Process of Using Controlled Gas Environments to Inhibit Microbial Growth |
US20100044296A1 (en) * | 2005-11-28 | 2010-02-25 | G3 Enterprises | Highly Selective Molecular Confinement for the Prevention and Removal of Taint in Foods and Beverages |
US8057671B2 (en) * | 2005-11-28 | 2011-11-15 | G3 Enterprises | Closure device capable of removing TCA in a beverage container |
WO2018014022A1 (en) * | 2016-07-15 | 2018-01-18 | University Of Florida Research Foundation, Incorporated | Permeation device for beneficial supplementation to gaseous atmospheres in enclosed volumes |
US20190246670A1 (en) * | 2016-07-15 | 2019-08-15 | University Of Florida Research Foundation, Inc. | Permeation device for beneficial supplementation to gaseous atmospheres in enclosed volumes |
Also Published As
Publication number | Publication date |
---|---|
GB1035720A (en) | 1966-07-13 |
NL6500073A (en) | 1965-07-12 |
FR1458943A (en) | 1966-11-10 |
MY6800013A (en) | 1968-12-31 |
CH458903A (en) | 1968-06-30 |
BE657875A (en) | 1965-07-05 |
SE321846B (en) | 1970-03-16 |
ES307015A1 (en) | 1965-05-16 |
IT950503B (en) | 1973-06-20 |
DE1492598A1 (en) | 1969-08-07 |
AT266567B (en) | 1968-11-25 |
DK126295B (en) | 1973-07-02 |
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