WO2000041805A1 - Method and membrane system for sterilizing and preserving liquids using carbon dioxide - Google Patents

Method and membrane system for sterilizing and preserving liquids using carbon dioxide Download PDF

Info

Publication number
WO2000041805A1
WO2000041805A1 PCT/US2000/000772 US0000772W WO0041805A1 WO 2000041805 A1 WO2000041805 A1 WO 2000041805A1 US 0000772 W US0000772 W US 0000772W WO 0041805 A1 WO0041805 A1 WO 0041805A1
Authority
WO
WIPO (PCT)
Prior art keywords
carbon dioxide
liquid
flow path
dense
flow
Prior art date
Application number
PCT/US2000/000772
Other languages
French (fr)
Inventor
Marc Sims
Original Assignee
Porocrit, L.L.C.
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 Porocrit, L.L.C. filed Critical Porocrit, L.L.C.
Priority to DK00908265.2T priority Critical patent/DK1156874T3/en
Priority to AU29648/00A priority patent/AU2964800A/en
Priority to EP00908265A priority patent/EP1156874B1/en
Priority to ES00908265T priority patent/ES2398741T3/en
Publication of WO2000041805A1 publication Critical patent/WO2000041805A1/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
    • A61L2/0005—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts
    • A61L2/0082—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts using chemical substances
    • A61L2/0088—Liquid substances
    • 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
    • A23L2/00—Non-alcoholic beverages; Dry compositions or concentrates therefor; Their preparation
    • A23L2/42—Preservation of non-alcoholic beverages
    • 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
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
    • A61L2/0005—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts
    • A61L2/0082—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor for pharmaceuticals, biologicals or living parts using chemical substances
    • A61L2/0094—Gaseous substances
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
    • B01D63/02—Hollow fibre modules
    • B01D63/033—Specific distribution of fibres within one potting or tube-sheet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • B01J19/2475—Membrane reactors
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00049—Controlling or regulating processes
    • B01J2219/00162—Controlling or regulating processes controlling the pressure
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S422/00—Chemical apparatus and process disinfecting, deodorizing, preserving, or sterilizing
    • Y10S422/905—Miscellaneous liquid sterilization means

Definitions

  • This invention relates to the sterilization and preservation of liquids such as liquid foods for example and more particularly to methods and apparatus for inactivating microbes and/or enzymes in liquids by exposure of the liquids to dense carbon dioxide.
  • Pasteurization is the most commonly used process for the purpose. Pasteuri- zation requires heating of the liquid to temperatures which can degrade the quality of the liquid. Heating of liquid foods for example can adversely affect the taste and nutritional quality of the food.
  • prior processes are static in that the dense CO2 and liquid are simply allowed to stand together in a pres- sure vessel for a period of time. The production rate of treated liquid is undesirably low.
  • Other prior processes are dynamic in that a forced dispersion of a flow of dense C0 2 into a flow of the liquid is brought about in a column which contains conventional packing such as rashig rings or a frit. Dispersive processes of this kind increase the production rate of treated liquid by creating a greater interfacial contact area between the dense CO2 and liquid than is present in the static processes. A still greater interface area between the liquid and dense CO2, in a given volume of flow, would be advantageous.
  • Dispersive processes of the above discussed kind are also subject to other problems. For example, emulsifica- tion of the liquid and dense CO2 can occur necessitating further steps to break the emulsion. Processing of liquids of certain densities may not be practical as a density difference between the liquid and dense CO2 is needed in order to separate the two. Fouling of components within the processing vessel may occur if the liquid contains suspended particulate matter.
  • the present invention is directed to overcoming one or more of the problems discussed above.
  • the invention provides a method for preserving a liquid by exposure of the liquid to pressurized dense carbon dioxide. Steps in the method include directing a flow of the liquid along a liquid flow path which extends along a first surface of a porous membrane and directing a flow of the dense carbon dioxide along a carbon dioxide flow path which extends along an opposite surface of the membrane including contacting the liquid and pressurized carbon dioxide at pores in the membrane. Further steps include recirculating the flow of dense carbon dioxide through the carbon dioxide flow path while maintaining the dense carbon dioxide in the pressurized state throughout the recirculation.
  • the method includes the further steps of establishing satu- ration of the dense carbon dioxide with the solute and maintaining saturation of the dense carbon dioxide with the solute during the recirculation of the dense carbon dioxide.
  • the invention provides apparatus for preserving liquids by exposure of the liquids to pressurized dense carbon dioxide.
  • Components of the apparatus include a membrane contactor having a liquid flow path and a carbon dioxide flow path therein. The flow paths are separated by porous membrane having pores which enable contact of a liquid flowing in the liquid flow path with carbon dioxide flowing in the carbon dioxide flow path.
  • a liquid pressurizing pump has an outlet communicated with the membrane contactor to direct liquid into the liquid flow path.
  • a dense carbon dioxide recirculation pump has an inlet communicated with the membrane contactor to receive pressurized dense carbon dioxide which flows out of the carbon dioxide flow path and has an outlet through which the pressurized dense carbon dioxide is returned to the carbon dioxide flow path.
  • the membrane contactor has a shell and a plurality of hollow fiber porous membranes extend in a generally parallel direction within the shell.
  • One of the liquid flow path and the carbon dioxide flow path extends through the lumen regions of the hollow fiber porous membranes and the other of the flow paths extends along exterior surfaces of the hollow fiber porous membranes.
  • the invention enables nondispersive contacting of flows of a liquid and dense C0 2 in which the area of contact of the two flows in a given volume is far greater than in prior static or dispersive processes .
  • the production rate of sterilized liquid is thereby increased.
  • Emulsion formation does not occur as dispersion of the C0 2 flow into the liquid flow is not required. It is not necessary that there be a density difference between the liquid and dense C0 2 in order to separate the two.
  • the invention does not require components which may be subject to fouling by suspended particulates in the liquid.
  • the process can be run continuously and isobarically thereby saving energy and equipment costs .
  • FIG. 1 is a schematic diagram depicting apparatus for sterilizing and preserving liquids in accordance with the invention.
  • FIG. 2 is a broken out side view of a preferred form of membrane contactor for use in the apparatus of FIG. 1.
  • FIG. 3 is a cross section view of the membrane contactor taken along line 3-3 of FIG. 2.
  • the invention is applicable to the treatment of any of the aqueous liquids which are known to be sterilizable by being contacted with dense carbon dioxide gas (C0 2 ) for a period of time sufficient to destroy microorganisms in the liquid.
  • C0 2 dense carbon dioxide gas
  • These are typically liquid foods such as fruit or vegetable juices for example or liquid medicines although other types of liquid may also be treated. It is believed that microorganism destruction occurs as a result of a temporary formation of carbonic acid in the liquid. It is also known that temporary exposure to dense C0 2 can be used to inactivate enzymes which may catalyze undesired changes in a liquid over a period of time.
  • the untreated liquid 11 which may be initially contained in an untreated liquid tank 12 is pressurized by a liquid feed pump 13 and delivered to a liquid flow path 14 situated within a membrane contactor 16.
  • a liquid feed pump 13 delivers to a liquid flow path 14 situated within a membrane contactor 16.
  • the membrane contactor 16 A preferred detailed construction for the membrane contactor 16 will hereinafter be described.
  • the liquid flow path 14 is separated from a dense C0 2 flow path 17 by porous membrane 18.
  • Contact of the liquid 11 with dense C0 2 occurs at minute pores 19 which penetrate through the membrane 18.
  • the dense C0 2 flow is continually recirculated through flow path 17 by a recirculation pump 21 having an inlet conduit 22 and an outlet conduit 23 connected to opposite ends of the membrane contactor 16.
  • the dense C0 2 is maintained in its pressurized condition throughout the recirculation process.
  • Pressurization of the dense C0 2 flow and the liquid flow within membrane contactor 16 may typically be in the range from about 1000 to about 3000 psi and operating temperature may be from about 20 to about 40°C although operation outside of these ranges is also possible. Dwell time of the liquid 11 within the membrane contactor 16 will vary for different liquids and can easily be determined for any particular liquid by examining the treated liquid to ascertain if undesired microorganisms have been destroyed.
  • the outflow of pressurized treated liquid from flow path 14 of membrane contactor 16 is delivered to a first receiver tank 24 through an outlet flow conduit 26.
  • Equalization of the pressure within the two flow paths 14 and 17 within membrane contactor 16 is assured by a pressure equalization conduit 27 which communicates the CO2 flow path 17 with the interior of the first receiver tank 24.
  • a pressure equalization conduit 27 which communicates the CO2 flow path 17 with the interior of the first receiver tank 24.
  • Treated fluid from the first receiver tank 24 is continuously released into a second receiver tank 28 through a pressure reducer valve 29.
  • the second receiver tank 28 is a low pressure tank and is preferably maintained at atmospheric pressure.
  • CO2 which has been acquired by the treated liquid separates out of the liquid within the low pressure tank 28.
  • a CO2 recovery compressor 31 has an intake conduit 32 communicated with the top region of the low pressure tank 28 and acts to liquefy the C0 2 which separates out in the tank 28.
  • Compressor 31 delivers the recovered C0 2 to a liquid C0 2 storage tank 33.
  • Make up C0 2 is transferred from the storage tank 33 to recirculation pump 21, through a make up pump 34, at a rate sufficient to maintain the desired operating pressure within the flow paths 14 and 17 of membrane contactor 16.
  • the process consumes only the amount of C0 2 that may be allowed to leave the processing apparatus in the treated liquid.
  • Treated liquid is drained from the base of the low pressure tank 28 into appropriate containers through another valve 36.
  • Membrane contactors 16 of the type used in the prac- tice of the present invention are sometimes used to extract desired constituents from a liquid when the constituent is soluble in dense CO2 •
  • the solute is separated from the CO2 flow by depressuring the CO2 in an expansion chamber or the like.
  • Unwanted extraction of any significant amount of such a solute need not occur in the practice of the present invention if the dense CO2 flow is maintained in its pressurized condition throughout the recirculation process. Under this condition, the dense CO2 flow is quickly saturated with constituents of the liquid that are soluble in C0 2 .
  • the constituents of the liquid which are soluble in C0 2 largely stay in the liquid after the recirculating CO2 flow becomes saturated with them. For example, fruit juices retain their aroma.
  • the membrane contactor 16 may be of any of various other forms but is preferably of the type depicted in FIGS. 2 and 3 which provides an extremely large interface area of contact between the liquid and dense CO2.
  • the contact area may be as much as 100 times greater in a given volume of liquid than is present in contactors of the hereinbefore discussed static or dynamic dispersive types.
  • the membrane 18 in a contactor 16 of this preferred type is a plurality of tubular hollow fiber porous membranes 37.
  • the fiber membranes 37 of this embodiment are linear and extend longitudinally, in a generally parallel and slightly spaced apart relationship, within a tubular shell 38. Ends of the fiber membranes 37 extend through end closures 39 at each end of shell 38.
  • a liquid inlet port member 41 at one end of shell 38 acts as a manifold which directs incoming untreated liquid into the adjacent ends of the hollow fiber membranes 37.
  • a similar liquid outlet port member 42 at the other end of the shell 38 receives liquid which has traveled through the membranes 37 and channels the liquid into the previously described liquid outlet conduit 26.
  • the lumens of the hollow fiber membranes 37 jointly provide the liquid flow path 14 of the membrane contactor 16 in this example of the invention.
  • a tubular dense gas flow inlet port 43 communicates with the interior of shell 38 at one end of the shell and a dense gas outlet port 44 communicates with the interior of the shell at the opposite end thereof.
  • portions of the interior of shell 38 which are outside of the hollow fiber membranes 37 provide the dense gas flow path 17 of the membrane contactor 16 in this embodiment of the invention.
  • Ports 38 and 39 and port members 36 and 37 protrude from a housing 45 which encloses the shell 33.
  • the membrane is formed of hydrophobic material such as polypropylene plas- tic as one example.
  • the membrane material may be of a hydrophilic type if the liquid is an oil or other hydrophobic fluid.
  • Pore diameter may vary depending on the characteristics of the particular membrane material and liquid but will typically be in the range from about 0.001 micron to about 1 micron if the wall thickness of the membranes is within the range from about 0.005mm to about 3mm. In general it is preferable to select the largest pore size which is observed to inhibit passage of the particular liquid through the membrane as this maximizes the interface area of the liquid and dense CO2.
  • a membrane contactor 16 of this type which is designed for commercial operation will typically contain more of the hollow fiber membranes 37 than are depicted in FIGS. 2 and 3.
  • Membrane contactors 16 which were used in the example of the practice of the method that is hereinafter described contained 120 such hollow fiber membranes 37.
  • the hollow fiber membranes 37 were formed of polypropylene plastic and had an inside diameter of 0.6mm, a wall thickness of 200 micrometers and were 40cm long.
  • the average size of the pores of the hollow fiber membranes 37 was 0.2 micrometers and the porosity of the fiber walls was 70%, porosity being the percentage of the membrane wall that is occupied by pores. It should be recognized that these specific materials and dimensions are presented for purposes of example and that other materials and dimensioning are also workable .
  • Fresh radish juice was contacted with high pressure CO2 while being pumped through two membrane contactors 16 of the type which has been hereinbefore described.
  • the two membrane contactors 16 were connected in series relationship and thus the radish juice passed sequentially through the two contactors.
  • Flow rate was 4.2 g/min.
  • the system was maintained at 200 bar pressure and 24°C temperature during the 24 minute experiment.
  • Average residence time of the juice in the membrane contactors 16 was 6 minutes.
  • the juice was retained in a raffinate receiver 24 for approximately another ten minutes before being drained into a beaker.
  • the dense CO2 treatment substantially reduced the i- crobial content of the juice as measured in plate counts which were as follows:
  • garlic puree processed in accordance with the invention does not change aroma as rapidly as the untreated puree.
  • the aroma change is catalyzed by the enzyme allinase, among others.
  • Fresh ginger root juice standing at room temperature in a sealed bottle has been observed to begin fermenting several days before the same juice which has been exposed to dense C0 2 in a membrane contactor of the previously described kind.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Organic Chemistry (AREA)
  • Food Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Water Supply & Treatment (AREA)
  • Nutrition Science (AREA)
  • Medicinal Chemistry (AREA)
  • Molecular Biology (AREA)
  • Epidemiology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • General Chemical & Material Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

Microorganisms are destroyed and enzymes can be inactivated in liquids, such as juices for example, by continuously flowing the the liquid and continuously flowing pressurized dense CO2 along flow paths (14, 17) which are separated by membrane (18) having minute pores (19) at which the flows contact each other are equalized and the dense CO2 flow is continuously recirculated without depressurization. Contact between the flows can be maximized by using a plurality of parallel hollow fiber porous membranes (37) with one of the flows being directed into the hollow fibers and the other of the flows being directed along exterior surfaces of the fibers. The process does not adversely affect properties of the liquid, such as taste, aroma and nutritional content, as heating of the liquid to a high temperature is unnecessary.

Description

METHOD AND MEMBRANE SYSTEM FOR STERILIZING AND PRESERVING
LIQUIDS USING CARBON DIOXIDE
Technical Field
This invention relates to the sterilization and preservation of liquids such as liquid foods for example and more particularly to methods and apparatus for inactivating microbes and/or enzymes in liquids by exposure of the liquids to dense carbon dioxide.
Background of the Invention
Preservation of many liquids such as juices or other liquid foods or medicines requires killing of microbes, such as bacteria, viruses and spores, in the liquid. It may also be necessary to inactivate enzymes which can catalyze undesired reactions in the liquid. Pasteurization is the most commonly used process for the purpose. Pasteuri- zation requires heating of the liquid to temperatures which can degrade the quality of the liquid. Heating of liquid foods for example can adversely affect the taste and nutritional quality of the food.
It has heretofore been recognized that liquids can be sterilized and preserved by contacting the liquids with pressurized dense CO2 (carbon dioxide) . The process does not require heating of the liquids to damaging temperatures. Prior processes and equipment for this purpose have not been ideally suited for commercial operation.
Some prior processes are static in that the dense CO2 and liquid are simply allowed to stand together in a pres- sure vessel for a period of time. The production rate of treated liquid is undesirably low. Other prior processes are dynamic in that a forced dispersion of a flow of dense C02 into a flow of the liquid is brought about in a column which contains conventional packing such as rashig rings or a frit. Dispersive processes of this kind increase the production rate of treated liquid by creating a greater interfacial contact area between the dense CO2 and liquid than is present in the static processes. A still greater interface area between the liquid and dense CO2, in a given volume of flow, would be advantageous.
Dispersive processes of the above discussed kind are also subject to other problems. For example, emulsifica- tion of the liquid and dense CO2 can occur necessitating further steps to break the emulsion. Processing of liquids of certain densities may not be practical as a density difference between the liquid and dense CO2 is needed in order to separate the two. Fouling of components within the processing vessel may occur if the liquid contains suspended particulate matter.
The present invention is directed to overcoming one or more of the problems discussed above.
Summary of the Invention
In one aspect, the invention provides a method for preserving a liquid by exposure of the liquid to pressurized dense carbon dioxide. Steps in the method include directing a flow of the liquid along a liquid flow path which extends along a first surface of a porous membrane and directing a flow of the dense carbon dioxide along a carbon dioxide flow path which extends along an opposite surface of the membrane including contacting the liquid and pressurized carbon dioxide at pores in the membrane. Further steps include recirculating the flow of dense carbon dioxide through the carbon dioxide flow path while maintaining the dense carbon dioxide in the pressurized state throughout the recirculation.
In another aspect of the invention, wherein the liquid has a constituent that is soluble in dense carbon dioxide and which becomes a solute in the dense carbon dioxide during passage of the carbon dioxide along the membrane, the method includes the further steps of establishing satu- ration of the dense carbon dioxide with the solute and maintaining saturation of the dense carbon dioxide with the solute during the recirculation of the dense carbon dioxide.
In another aspect the invention provides apparatus for preserving liquids by exposure of the liquids to pressurized dense carbon dioxide. Components of the apparatus include a membrane contactor having a liquid flow path and a carbon dioxide flow path therein. The flow paths are separated by porous membrane having pores which enable contact of a liquid flowing in the liquid flow path with carbon dioxide flowing in the carbon dioxide flow path. A liquid pressurizing pump has an outlet communicated with the membrane contactor to direct liquid into the liquid flow path. A dense carbon dioxide recirculation pump has an inlet communicated with the membrane contactor to receive pressurized dense carbon dioxide which flows out of the carbon dioxide flow path and has an outlet through which the pressurized dense carbon dioxide is returned to the carbon dioxide flow path.
In sill another aspect of the invention, the membrane contactor has a shell and a plurality of hollow fiber porous membranes extend in a generally parallel direction within the shell. One of the liquid flow path and the carbon dioxide flow path extends through the lumen regions of the hollow fiber porous membranes and the other of the flow paths extends along exterior surfaces of the hollow fiber porous membranes.
The invention enables nondispersive contacting of flows of a liquid and dense C02 in which the area of contact of the two flows in a given volume is far greater than in prior static or dispersive processes . The production rate of sterilized liquid is thereby increased. Emulsion formation does not occur as dispersion of the C02 flow into the liquid flow is not required. It is not necessary that there be a density difference between the liquid and dense C02 in order to separate the two. The invention does not require components which may be subject to fouling by suspended particulates in the liquid. The process can be run continuously and isobarically thereby saving energy and equipment costs .
The invention, together with further aspects and advantages thereof, may be further understood by reference to the following description of the preferred embodiment and by reference to the accompanying drawings .
Brief Description of the Drawings
FIG. 1 is a schematic diagram depicting apparatus for sterilizing and preserving liquids in accordance with the invention.
FIG. 2 is a broken out side view of a preferred form of membrane contactor for use in the apparatus of FIG. 1. FIG. 3 is a cross section view of the membrane contactor taken along line 3-3 of FIG. 2.
Detailed Description of the preferred Embodiment
The invention is applicable to the treatment of any of the aqueous liquids which are known to be sterilizable by being contacted with dense carbon dioxide gas (C02) for a period of time sufficient to destroy microorganisms in the liquid. These are typically liquid foods such as fruit or vegetable juices for example or liquid medicines although other types of liquid may also be treated. It is believed that microorganism destruction occurs as a result of a temporary formation of carbonic acid in the liquid. It is also known that temporary exposure to dense C02 can be used to inactivate enzymes which may catalyze undesired changes in a liquid over a period of time.
Referring initially to FIG. 1 of the drawings, the untreated liquid 11 which may be initially contained in an untreated liquid tank 12 is pressurized by a liquid feed pump 13 and delivered to a liquid flow path 14 situated within a membrane contactor 16. A preferred detailed construction for the membrane contactor 16 will hereinafter be described. Within the membrane contactor 16, the liquid flow path 14 is separated from a dense C02 flow path 17 by porous membrane 18. Contact of the liquid 11 with dense C02 occurs at minute pores 19 which penetrate through the membrane 18. The dense C02 flow is continually recirculated through flow path 17 by a recirculation pump 21 having an inlet conduit 22 and an outlet conduit 23 connected to opposite ends of the membrane contactor 16. The dense C02 is maintained in its pressurized condition throughout the recirculation process.
Pressurization of the dense C02 flow and the liquid flow within membrane contactor 16 may typically be in the range from about 1000 to about 3000 psi and operating temperature may be from about 20 to about 40°C although operation outside of these ranges is also possible. Dwell time of the liquid 11 within the membrane contactor 16 will vary for different liquids and can easily be determined for any particular liquid by examining the treated liquid to ascertain if undesired microorganisms have been destroyed. The outflow of pressurized treated liquid from flow path 14 of membrane contactor 16 is delivered to a first receiver tank 24 through an outlet flow conduit 26. Equalization of the pressure within the two flow paths 14 and 17 within membrane contactor 16 is assured by a pressure equalization conduit 27 which communicates the CO2 flow path 17 with the interior of the first receiver tank 24. Thus there is no significant pressure gradient between the two flow paths 14 and 17 which might act to force transfer of fluid therebetween.
Treated fluid from the first receiver tank 24 is continuously released into a second receiver tank 28 through a pressure reducer valve 29. The second receiver tank 28 is a low pressure tank and is preferably maintained at atmospheric pressure. CO2 which has been acquired by the treated liquid separates out of the liquid within the low pressure tank 28. A CO2 recovery compressor 31 has an intake conduit 32 communicated with the top region of the low pressure tank 28 and acts to liquefy the C02 which separates out in the tank 28. Compressor 31 delivers the recovered C02 to a liquid C02 storage tank 33. Make up C02 is transferred from the storage tank 33 to recirculation pump 21, through a make up pump 34, at a rate sufficient to maintain the desired operating pressure within the flow paths 14 and 17 of membrane contactor 16. Thus the process consumes only the amount of C02 that may be allowed to leave the processing apparatus in the treated liquid.
Treated liquid is drained from the base of the low pressure tank 28 into appropriate containers through another valve 36.
Membrane contactors 16 of the type used in the prac- tice of the present invention are sometimes used to extract desired constituents from a liquid when the constituent is soluble in dense CO2 • In those processes the solute is separated from the CO2 flow by depressuring the CO2 in an expansion chamber or the like. Unwanted extraction of any significant amount of such a solute need not occur in the practice of the present invention if the dense CO2 flow is maintained in its pressurized condition throughout the recirculation process. Under this condition, the dense CO2 flow is quickly saturated with constituents of the liquid that are soluble in C02. The constituents of the liquid which are soluble in C02 largely stay in the liquid after the recirculating CO2 flow becomes saturated with them. For example, fruit juices retain their aroma.
The membrane contactor 16 may be of any of various other forms but is preferably of the type depicted in FIGS. 2 and 3 which provides an extremely large interface area of contact between the liquid and dense CO2. The contact area may be as much as 100 times greater in a given volume of liquid than is present in contactors of the hereinbefore discussed static or dynamic dispersive types.
The membrane 18 in a contactor 16 of this preferred type is a plurality of tubular hollow fiber porous membranes 37. The fiber membranes 37 of this embodiment are linear and extend longitudinally, in a generally parallel and slightly spaced apart relationship, within a tubular shell 38. Ends of the fiber membranes 37 extend through end closures 39 at each end of shell 38. A liquid inlet port member 41 at one end of shell 38 acts as a manifold which directs incoming untreated liquid into the adjacent ends of the hollow fiber membranes 37. A similar liquid outlet port member 42 at the other end of the shell 38 receives liquid which has traveled through the membranes 37 and channels the liquid into the previously described liquid outlet conduit 26. Thus the lumens of the hollow fiber membranes 37 jointly provide the liquid flow path 14 of the membrane contactor 16 in this example of the invention.
A tubular dense gas flow inlet port 43 communicates with the interior of shell 38 at one end of the shell and a dense gas outlet port 44 communicates with the interior of the shell at the opposite end thereof. Thus portions of the interior of shell 38 which are outside of the hollow fiber membranes 37 provide the dense gas flow path 17 of the membrane contactor 16 in this embodiment of the invention. Ports 38 and 39 and port members 36 and 37 protrude from a housing 45 which encloses the shell 33.
The above described porting arrangements can be re- versed so that the incoming untreated liquid flows into one of the ports 43 and 44 and out of the other while the dense CO2 is directed into one of the port members 41 and 42 and flows out of the other port member. In this alternate arrangement the lumens of the fiber membranes 37 function as the dense CO2 flow path of the membrane contactor 13 while the interior region of shell 38 that is outside of the membranes functions as the liquid flow path of the contactor.
Passage of liquid through the pores of the fiber membranes 37 is inhibited by using a membrane material which is not wetted by the liquid and by limiting the size of the pores. In the case of aqueous liquids the membrane is formed of hydrophobic material such as polypropylene plas- tic as one example. The membrane material may be of a hydrophilic type if the liquid is an oil or other hydrophobic fluid. Pore diameter may vary depending on the characteristics of the particular membrane material and liquid but will typically be in the range from about 0.001 micron to about 1 micron if the wall thickness of the membranes is within the range from about 0.005mm to about 3mm. In general it is preferable to select the largest pore size which is observed to inhibit passage of the particular liquid through the membrane as this maximizes the interface area of the liquid and dense CO2.
A membrane contactor 16 of this type which is designed for commercial operation will typically contain more of the hollow fiber membranes 37 than are depicted in FIGS. 2 and 3. Membrane contactors 16 which were used in the example of the practice of the method that is hereinafter described contained 120 such hollow fiber membranes 37. The hollow fiber membranes 37 were formed of polypropylene plastic and had an inside diameter of 0.6mm, a wall thickness of 200 micrometers and were 40cm long. The average size of the pores of the hollow fiber membranes 37 was 0.2 micrometers and the porosity of the fiber walls was 70%, porosity being the percentage of the membrane wall that is occupied by pores. It should be recognized that these specific materials and dimensions are presented for purposes of example and that other materials and dimensioning are also workable .
Example of the Method
Fresh radish juice was contacted with high pressure CO2 while being pumped through two membrane contactors 16 of the type which has been hereinbefore described. The two membrane contactors 16 were connected in series relationship and thus the radish juice passed sequentially through the two contactors. Flow rate was 4.2 g/min. The system was maintained at 200 bar pressure and 24°C temperature during the 24 minute experiment. Average residence time of the juice in the membrane contactors 16 was 6 minutes. The juice was retained in a raffinate receiver 24 for approximately another ten minutes before being drained into a beaker.
The dense CO2 treatment substantially reduced the i- crobial content of the juice as measured in plate counts which were as follows:
Figure imgf000012_0001
(Less than 10 per g is equivalent to nondetectable )
It has also been observed that garlic puree processed in accordance with the invention does not change aroma as rapidly as the untreated puree. The aroma change is catalyzed by the enzyme allinase, among others. Fresh ginger root juice standing at room temperature in a sealed bottle has been observed to begin fermenting several days before the same juice which has been exposed to dense C02 in a membrane contactor of the previously described kind.
While the invention has been described with reference to a specific embodiment for purposes of example, many modifications and variations are possible and it is not intended to limit the invention except as defined in the following claims:

Claims

Claims
1. A method for preserving a liquid by exposure of the liquid to pressurized dense carbon dioxide comprising the steps of: directing a flow of said liquid along a liquid flow path which extends along a first surface of a porous membrane and directing a flow of said pressurized dense carbon dioxide along a carbon dioxide flow path which extends along an opposite surface of said porous membrane including contacting said liquid and pressurized dense carbon dioxide at pores in said membrane, and recirculating said flow of pressurized dense carbon dioxide through said carbon dioxide flow path including maintaining the dense carbon dioxide in the pressurized condition throughout the recirculation thereof.
2. The method of claim 1 including the further step of maintaining substantially the same elevated pressure in said liquid flow path and in said carbon dioxide flow path.
3. The method of claim 1 wherein said liquid has a constituent that is soluble in dense carbon dioxide and which becomes a solute in said dense carbon dioxide during passage of said dense carbon dioxide along said carbon dioxide flow path, including the further step of establishing saturation of said dense carbon dioxide with said solute and maintaining said saturation of said dense carbon dioxide with said solute during said recirculation of said dense carbon dioxide.
4. The method of claim 1 including the further steps of continuously receiving liquid from said liquid flow path in a first receiver tank and maintaining said first receiver tank at a pressure which is substantially the same as the pressure within said carbon dioxide flow path.
5. The method of claim 4 including the further steps of depressurizing said liquid while continuously releasing the liquid from said first receiver tank into a second receiver tank, recovering low pressure carbon dioxide from said second receiver tank, recompressing the recovered low pressure carbon dioxide and returning recompressed carbon dioxide to said carbon dioxide flow path.
6. The method of claim 1 wherein said liquid flow path and carbon dioxide flow path are defined by a plurality of hollow fiber porous membranes, including directing one of said flow of liquid and said flow of dense carbon dioxide through into said hollow fiber porous membranes and directing the other of said flow of liquid and said flow of dense carbon dioxide along external surfaces of said hollow fiber porous membranes.
7. The method of claim 1 including continuously flowing said liquid along said liquid flow path and continuously flowing said pressurized dense carbon dioxide along said carbon dioxide flow path.
8. The method of claim 1 including contacting said liquid and said dense carbon dioxide for a period sufficient to sterilize said liquid.
9. The method of claim 1 including contacting said liquid and said dense carbon dioxide for a period sufficient to inactivate an enzyme in said liquid.
10. Apparatus for preserving liquids by exposure of the liquids to pressurized dense carbon dioxide comprising: a membrane contactor having a liquid flow path and a carbon dioxide flow path therein, said flow paths being separated by porous membrane having pores which enable contact of a. liquid flowing in said liquid flow path with carbon dioxide flowing in the carbon dioxide flow path, a liquid pressurizing pump having an outlet communi- cated with said membrane contactor to direct liquid into said liquid flow path, and a dense carbon dioxide recirculation pump having an inlet communicated with said membrane contactor to receive pressurized dense carbon dioxide which flows out of said carbon dioxide flow path and having an outlet communicated with said membrane contactor to return the pressurized dense carbon dioxide to said carbon dioxide flow path.
11. The apparatus of claim 10 wherein said membrane contactor includes a shell and a plurality of hollow fiber porous membranes extending in a generally parallel direction within said shell, and wherein one of said flow paths extends through lumen regions of said hollow fiber porous membranes and the other of said flow paths extends along exterior surfaces of said hollow fiber porous membranes.
12. The apparatus of claim 10 further including a first receiver tank having an inlet communicated with said membrane contactor to receive liquid from said liquid flow path, further including a pressure equalizing flow conduit communicating said dense carbon dioxide flow path with said first receiver tank.
13. The apparatus of claim 12 further including a second receiver tank having an inlet communicated with said first receiver tank to receive liquid therefrom through a pressure reducer.
14. The apparatus of claim 13 further including a liquid carbon dioxide storage tank, means for releasing carbon dioxide from said storage tank to said carbon dioxide flow path to maintain a particular operating pressure therein, and a compressor recovering low pressure carbon dioxide from said second receiver tank and which liquefies the recovered carbon dioxide, said compressor having an outlet communicated with said liquid carbon dioxide storage tank.
15. The apparatus of claim 10 wherein said membrane contactor includes a tubular shell and a plurality of substantially parallel hollow fiber porous membranes extending in a generally axial direction therein and wherein one of said flow paths extends through lumen regions of said hollow fiber porous membranes and the other of said flow paths extends along exterior surfaces of said hollow fiber porous membranes further including: a first receiver tank having an inlet communicated with said membrane contactor to receive liquid from said liquid flow path, a pressure equalizing flow conduit communicating said dense carbon dioxide flow path with said first receiver tank, and a second receiver tank having an inlet communicated with said first receiver tank to receive treated liquid therefrom through a pressure reducer.
PCT/US2000/000772 1999-01-12 2000-01-12 Method and membrane system for sterilizing and preserving liquids using carbon dioxide WO2000041805A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DK00908265.2T DK1156874T3 (en) 1999-01-12 2000-01-12 Method and membrane system for sterilizing and retaining fluids using carbon dioxide
AU29648/00A AU2964800A (en) 1999-01-12 2000-01-12 Method and membrane system for sterilizing and preserving liquids using carbon dioxide
EP00908265A EP1156874B1 (en) 1999-01-12 2000-01-12 Method and membrane system for sterilizing and preserving liquids using carbon dioxide
ES00908265T ES2398741T3 (en) 1999-01-12 2000-01-12 Procedure and system of membranes to sterilize and conserve liquids using carbon dioxide

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/228,925 US6331272B1 (en) 1999-01-12 1999-01-12 Method and membrane system for sterilizing and preserving liquids using carbon dioxide
US09/228,925 1999-01-12

Publications (1)

Publication Number Publication Date
WO2000041805A1 true WO2000041805A1 (en) 2000-07-20

Family

ID=22859113

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/000772 WO2000041805A1 (en) 1999-01-12 2000-01-12 Method and membrane system for sterilizing and preserving liquids using carbon dioxide

Country Status (7)

Country Link
US (1) US6331272B1 (en)
EP (1) EP1156874B1 (en)
AU (1) AU2964800A (en)
DK (1) DK1156874T3 (en)
ES (1) ES2398741T3 (en)
PT (1) PT1156874E (en)
WO (1) WO2000041805A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108618564A (en) * 2017-03-20 2018-10-09 佛山市顺德区美的电热电器制造有限公司 Cooking apparatus and sterilization control method
CN114247395A (en) * 2020-09-23 2022-03-29 中国科学院大连化学物理研究所 Hollow fiber membrane type micro-channel reactor and application

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030170359A1 (en) 1997-03-13 2003-09-11 Garwood Anthony J. M. Method for controlling water content with decontamination in meats
US20020110625A1 (en) * 1997-03-13 2002-08-15 Case Ready Solutions, Llc. Continuous packaging in enclosed conduits
US6471995B1 (en) * 2000-09-27 2002-10-29 Alkermes Controlled Therapeutics, Inc. Ii Apparatus and method for preparing microparticles using liquid-liquid extraction
US20040033296A1 (en) * 2002-05-14 2004-02-19 Yuan James T. C. Method of using low temperature and high/low pressure processing to preserve food products
DE10247865A1 (en) * 2002-10-14 2004-04-22 Weda-Dammann & Westerkamp Gmbh Preparation of liquid animal feed adds a sterilizing ozone gas to be mixed with it, to prevent fermentation of the organic feed and reduce germs
US20050266128A1 (en) * 2004-04-28 2005-12-01 Yuan James T Novel method of preserving food products using pressure selective agents
WO2005112659A2 (en) * 2004-05-21 2005-12-01 Cornell Research Foundation, Inc. Extended shelf life and bulk transport of perishable organic liquids with low pressure carbon dioxide
US20060201342A1 (en) * 2005-03-01 2006-09-14 Paganessi Joseph E Use of porous metal membrane for treating liquid foods
US20060251542A1 (en) * 2005-05-05 2006-11-09 Marc Sims Method for sterilizing articles using carbonated water
US7666369B2 (en) 2006-09-29 2010-02-23 Tyco Healthcare Group Lp System and method for recycling sterilant gas
US8268238B2 (en) 2006-09-29 2012-09-18 Tyco Healthcare Group Lp System and method for recycling sterilant gas
US20100310743A1 (en) * 2009-06-04 2010-12-09 Dean Intellectual Property Services, Inc. Removing gas additives from raw milk
US20110076359A1 (en) * 2009-09-28 2011-03-31 Dean Intellectual Property Services, Inc. Removing gas additives from raw milk
WO2015077508A1 (en) 2013-11-20 2015-05-28 University Of Florida Research Foundation, Inc. Carbon dioxide reduction over carbon-containing materials

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04135470A (en) 1990-09-28 1992-05-08 Toppan Printing Co Ltd Apparatus for high-pressure treatment
US5358732A (en) * 1993-08-10 1994-10-25 Albert Einstein College Of Medicine Of Yeshiva University Method and system for removing impurities from aliments
US5393547A (en) 1988-09-12 1995-02-28 University Of Florida Inactivation of enzymes in foods with pressurized CO2
US5490884A (en) 1994-09-09 1996-02-13 Tastemaker Method and system for extracting a solute from a fluid using dense gas and a porous membrane
US5704276A (en) 1996-01-29 1998-01-06 Shimadzu Corporation System for processing liquid foodstuff or liquid medicine with a supercritical fluid of carbon dioxide

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5393547A (en) 1988-09-12 1995-02-28 University Of Florida Inactivation of enzymes in foods with pressurized CO2
JPH04135470A (en) 1990-09-28 1992-05-08 Toppan Printing Co Ltd Apparatus for high-pressure treatment
US5358732A (en) * 1993-08-10 1994-10-25 Albert Einstein College Of Medicine Of Yeshiva University Method and system for removing impurities from aliments
US5490884A (en) 1994-09-09 1996-02-13 Tastemaker Method and system for extracting a solute from a fluid using dense gas and a porous membrane
US5704276A (en) 1996-01-29 1998-01-06 Shimadzu Corporation System for processing liquid foodstuff or liquid medicine with a supercritical fluid of carbon dioxide

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
ARREOLA ET AL., JOURNAL OF FOOD SCIENCES, vol. 56, 1991, pages 1030 - 1033
KAMIHIRA ET AL., AGRICULTURAL AND BIOLOGICAL CHEMISTRY, vol. 51, 1987, pages 407 - 412
See also references of EP1156874A4

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108618564A (en) * 2017-03-20 2018-10-09 佛山市顺德区美的电热电器制造有限公司 Cooking apparatus and sterilization control method
CN114247395A (en) * 2020-09-23 2022-03-29 中国科学院大连化学物理研究所 Hollow fiber membrane type micro-channel reactor and application
CN114247395B (en) * 2020-09-23 2023-04-25 中国科学院大连化学物理研究所 Hollow fiber membrane type microchannel reactor and application thereof

Also Published As

Publication number Publication date
EP1156874B1 (en) 2012-12-12
EP1156874A1 (en) 2001-11-28
PT1156874E (en) 2013-01-28
EP1156874A4 (en) 2004-06-09
ES2398741T3 (en) 2013-03-21
DK1156874T3 (en) 2013-03-25
AU2964800A (en) 2000-08-01
US6331272B1 (en) 2001-12-18

Similar Documents

Publication Publication Date Title
US6331272B1 (en) Method and membrane system for sterilizing and preserving liquids using carbon dioxide
EP2181612B1 (en) Food processing method and food processing apparatus
Bevilacqua et al. Nonthermal technologies for fruit and vegetable juices and beverages: Overview and advances
Mangindaan et al. Beverage dealcoholization processes: Past, present, and future
EP2915437B1 (en) Apparatus for instantaneous expansion with vacuum and ultrasound waves
WO1990002799A1 (en) Inactivation of enzymes in food products with pressurized co¿2?
JP3424654B2 (en) Liquid substance continuous treatment method, continuous treatment apparatus and liquid substance treated by them
JP2006333835A (en) Method for treating liquid state fluid by utilizing high pressure carbon dioxide
CA2280240C (en) Method and apparatus for continuous flow reduction of microbial activity in a liquid product using pressurized carbon dioxide
US6723365B2 (en) Method and apparatus for continuous flow reduction of microbial and/or enzymatic activity in a liquid product using carbon dioxide
JPH06292546A (en) Production of fruit juice
US20060201342A1 (en) Use of porous metal membrane for treating liquid foods
JP3397148B2 (en) Liquid substance continuous processing method, continuous processing apparatus and liquid food and drink treated by them
Mounir et al. Extraction of fruit juices
WO2002003816A1 (en) Treating liquid products using carbon dioxide
JP2820625B2 (en) Enzyme inactivation method for liquid food
US20040131739A1 (en) Method and apparatus for continuous flow reduction of microbial and/or enzymatic activity in a liquid product using carbon dioxide
JPH07222553A (en) Method for degassing tea drink
JP2001128652A (en) Continuous treating device of liquid state material and liquid material treated with the same
CA2473995A1 (en) Method and apparatus for continuous flow reduction of microbial activity in a liquid product using pressurized carbon dioxide
US20040234661A1 (en) Method and apparatus for continuous flow reduction of microbial and/or enzymatic activity in a liquid beer product using carbon dioxide
RU2222238C2 (en) Method for canning of liquid or pasty food products
JP3300755B2 (en) Squeezed juice high pressure treatment method and apparatus
RU2030873C1 (en) Method and apparatus for vacuum sterilization of food product
MXPA99007374A (en) Method and apparatus for continuous reduction of microbial activity flow in a liquid product using carbon dioxide presuriz

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU BR CN HU ID IN JP KR MX NO PL RU

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2000908265

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2000908265

Country of ref document: EP