Classifications

• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B7/00—Preservation or chemical ripening of fruit or vegetables
  • A23B7/005—Preserving by heating
  • A23B7/0053—Preserving by heating by direct or indirect contact with heating gases or liquids
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B7/00—Preservation or chemical ripening of fruit or vegetables
  • A23B7/02—Dehydrating; Subsequent reconstitution
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B9/00—Preservation of edible seeds, e.g. cereals
  • A23B9/02—Preserving by heating
  • A23B9/025—Preserving by heating with use of gases
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
  • A23B9/00—Preservation of edible seeds, e.g. cereals
  • A23B9/08—Drying; Subsequent reconstitution

Definitions

• the present invention relates to a method and apparatus for sterilizing organic particulates. More particularly, the present invention relates to a method and apparatus for sterilizing seeds, herbs, spices and the like.
• Sterilization treatments of seeds, herbs and spices must meet several conflicting requirements. For example, it is desirable to preserve the aroma, flavor and appearance of the sterilized product. Since the aroma and flavor are derived in large part from volatile oils contained within the SHS, it is desirable to minimize the loss of these volatile oils during processing. In addition, it is desirable to produce and maintain a reduced level of moisture in the sterilized product to ensure a sufficiently long shelf life. On the other hand, harmful bacteria and other microbes must be destroyed so that the food will be safe for human consumption. Another requirement is that the product be processed as efficiently as possible, i.e. continuous sterilization is preferred to batch processing.
• the present invention fills these needs by providing a method and apparatus for rapidly and continuously sterilizing food products such as seeds, herbs and spices operating under unique processing conditions.
• the present invention provides a continuous method for sterilizing organic particulates in which organic particulates are quickly passed through a steam atmosphere in a pressure vessel at superatmospheric pressure.
• the time taken for the organic particulates to pass through the pressure vessel will reduce the microbial load without either substantial volatilization of oils from within the particulates or substantial degradation of the organic particulates.
• the sterilized particulates are then quickly cooled while still under pressure to a temperature below the "flash point" of the volatile oils: that is, they are cooled to below the temperature at which the volatile oils will flash when the particulates are discharged.
• the product is then discharged for drying and further processing, if necessary.
• an apparatus capable of carrying out a continuous sterilization process includes a first pressure vessel having an inlet for organic particulates and an outlet for sterilized organic particulates, a means for heating the organic particulates within the vessel at a first pressure that is greater than atmospheric pressure, a second pressure vessel coupled to the outlet of the first vessel, and means for cooling the organic particulates within the second vessel while maintaining a superatmospheric pressure.
• Figure 1 is a block-type flow diagram setting forth a method of the present invention for sterilizing seeds, herbs and spices;
• Figure 2 is an apparatus according to the invention capable of performing the inventive method.
• organic particulates or "SHS” will denote seeds, herbs, spices and other food products including, but not limited to, anise, caraway, cardamom, celery, dill, fennel, pepper, basil, parsley, oregano, dill, sage, cracked bay leaf, paprika and many others as are commonly processed in the spice and herb industry. More specifically, the term “particulates” is intended to encompass any of these plants and seeds in their as collected state where they are naturally found as small particles, as well as in their chopped, ground or crushed form.
• raw is used to denote the state of organic particulates prior to sterilization according to the invention.
• raw organic particulates used as feed to the present process may have previously undergone cleaning, chopping, sorting or other common processing steps prior to sterilization.
• the method of the present invention will now be generally described in connection with Figure 1.
• the basic process steps of the invention are shown along with process parameters of the invention.
• the process is intended to be substantially continuous, whereby in step 1 , raw organic particulates are fed from a hopper 1 16 into a sterilizer 1 12.
• the feed will necessarily pass through a pressure isolation device between the hopper 116 and sterilizer 112, such as a variable speed rotary valve capable of high differential pressure.
• the organic particulates are sterilized in sterilizer 1 12 by a means for heating.
• the means for heating is chosen to be capable of quickly heating the organic particulates to a high temperature at superatmospheric pressure.
• the means for heating may be steam, or other hot inert gases, such as air or nitrogen or mixtures thereof.
• steam heat will be used.
• the steam may be saturated or superheated and will generally be limited to 285°F, thereby allowing product sterilization with minimal product degradation. Further, the drier the steam, the lower the microbial kill rate.
• the sterilizer 1 12 may be a jacketed vessel in which the walls of the vessel can also be heated to thereby avoid condensation on the inside walls of the vessel.
• the temperature, pressure, and dwell time in the sterilizer 112 are chosen to achieve sterilization of the organic particulates without significant volatile oil loss or product degradation. Exposure of the raw organic particulates to temperatures of about 215-285°F for less than one minute, e.g., 1-30 seconds, is suitable to achieve sterilization. In one embodiment, the necessary temperatures required are achieved by maintaining a pressure of about 20 psig in the sterilizer 1 12 (psig is the gauge pressure, i.e. the pressure measured in excess of atmospheric pressure). By minimizing the residence time in the sterilizer, the degree of volatilization of oils in the SHS is also minimized.
• pressure within the sterilizer 1 12 may be controlled in a range between about 5 psig and about 40 psig while the temperature within the sterilizer 1 12 may be controlled in a range from about 215°F to about 285°F.
• the SHS is transferred in step 3 to a separate pressure vessel 124 for cooling.
• a separate pressure vessel 124 for cooling allows the process to be virtually continuous.
• the organic particulates are less stable with respect to volatile oil flashing when they are hot because the membranes containing the volatile oils are stressed. When the hot organic particulates are subject to rapid pressure changes these membranes rupture, releasing the volatile oils and allowing their subsequent volatilization.
• the present invention overcomes this drawback by maintaining the organic particulates at a superatmospheric pressure during the cooling process. In this way, the hot product is not subject to the rapid pressure changes that lead to flashing of the volatile oils.
• the organic particulates are discharged for further processing only after they have been cooled. Therefore, only cooled SHS are subjected to rapid pressure changes and, since the cooled products are more stable with respect to volatile oil flashing, volatile oil loss is diminished.
• the means for cooling is chosen to quickly cool the sterilized product at superatmospheric pressure.
• the means for cooling may be cooling gasses or fluids such as compressed air, gaseous nitrogen, compressed air/nitrogen mixtures, and liquid nitrogen.
• the pressure during cooling may approximate that extant during the heating step or may be slightly less to facilitate passage of the sterilized organic particulates to the cooling vessel and to maintain temperature in the heating vessel. For example, when heating is carried out at about 20 psig, cooling may be carried out at about 18-19 psig.
• the sterilized product having desirable levels of volatile oils is recovered via passage of the SHS through a last pressure isolation device from the cooling chamber to the external environment that is at a given pressure.
• the external environment is at atmospheric pressure.
• the moisture content of the finished sterilized particulates is desirably between about 5 to 10 wt%.
• This moisture content may be achieved in step 4 in which the cooled product is discharged from the cooling chamber into a dryer 130.
• the dryer 130 uses mild drying conditions, thus drying the sterilized particulates to give the required moisture content without product degradation or volatile oil loss.
• the control of moisture levels in the product which can be achieved by the invention results in water activity levels below 0.58, i.e. the threshold at which growth of microorganisms will spontaneously occur.
• the process achieves a substantial reduction in "Standard Plate Count" ("SPC”), using standard tests for determining microbial load before and after the sterilization process.
• SPC Standard Plate Count
• apparatus 10 includes a sealed, jacketed sterilization pressure vessel 12 having an inlet 14 for feeding raw organic particulates from hopper 16, and an outlet 18 for discharging sterilized organic particulates.
• the inlet 14 includes a pressure isolation valve 1 1 which is used to maintain a pressure difference between the feed hopper and the sterilizer.
• a conveyor such as a variable speed screw 13, is powered by a motor 20 and is positioned to transport the SHS along the length of the vessel 12 toward the outlet 18.
• Many other means for transporting the SHS within the vessel can be used, or the vessel may be rotated at an angle which moves the contents along the length thereof, or other conveyors.
• the means for transporting the SHS may also act to mix the SHS. Further, as is well known, it is possible to internally heat the screw or transport means to the same temperature as the walls of the vessel to thereby avoid condensation of moisture or volatiles thereon.
• pressure vessel 12 For heating, pressure vessel 12 includes an inlet 22 for directing a heating medium, such as steam, into the vessel for direct treatment of the SHS.
• a heating medium such as steam
• the jacket of vessel 12 may also be heated either by steam or by an electrical coil.
• an outlet (not shown) can be provided for draining condensate from the vessel.
• the heating medium is super-heated or saturated steam under pressure conditions such that microbes in the organic particulates are reduced to acceptable levels without substantial loss of volatile oil.
• the residence time of the organic particulates in the heating region should be the minimum necessary to effect sterilization.
• the particulates will pass out of vessel 12 through outlet 18, through pressure isolation valve 28, and through inlet 21 to a second pressure vessel 24.
• the organic particulates are then transported along the length of the vessel 24 towards an outlet 30 by a conveyor 25 powered by a motor 26.
• the means for transporting the organic particulates 25 may be the same as the conveyor 13 or may be different.
• This vessel will include an inlet 26 for introducing a cooling medium, such as air, nitrogen, or air/nitrogen mixtures, into the interior of the vessel 24, and may also include a cooling jacket/coil. As necessary, an appropriate outlet passage for used liquids and/or gasses will be included in the vessel.
• a cooling medium such as air, nitrogen, or air/nitrogen mixtures
• the dwell time in the cooler is equal to or less than the dwell time in the heater.
• the dwell time in the cooler is chosen so that the sterilized organic particulates are cooled to a temperature at which the volatile oils in the product are stable with respect to the rapid pressure drop to atmospheric pressure experienced upon product discharge.
• the dwell time will depend on the product being sterilized and the cooling means employed. For example, using air, nitrogen, or air/nitrogen mixtures as the cooling means dwell times between 1 and 20 seconds are sufficient for cooling black pepper, cracked bay leaf, paprika, oregano, and basil.
• the dwell time in the cooling vessel is substantially equal to the dwell time in the heating vessel.
• the heating and cooling fluids will be food (culinary) grade.
• the product is discharged through a last pressure isolation valve 29.
• the cooled product is then dried in dryer 31 , if necessary, and the dried sterilized product is then discharged for further processing and packaging.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Food Science & Technology (AREA)
• Polymers & Plastics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
• Seasonings (AREA)
• Fats And Perfumes (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Cited By (1)

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• 1995
  • 1995-12-29 EP EP95944568A patent/EP0755190A1/de not_active Withdrawn
  • 1995-12-29 WO PCT/US1995/017060 patent/WO1996020606A1/en not_active Application Discontinuation
  • 1995-12-29 CN CN 95192647 patent/CN1146137A/zh active Pending
  • 1995-12-29 BR BR9507120A patent/BR9507120A/pt not_active Application Discontinuation
  • 1995-12-29 MX MX9603755A patent/MX9603755A/es unknown
  • 1995-12-29 CA CA 2184384 patent/CA2184384A1/en not_active Abandoned
  • 1995-12-29 AU AU46912/96A patent/AU4691296A/en not_active Abandoned
• 1996
  • 1996-12-20 AR ARP960105803A patent/AR005165A1/es unknown

Non-Patent Citations (1)

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