WO2006010043A2

WO2006010043A2 - System and method for pathogen control in reprocessing of foods

Info

Publication number: WO2006010043A2
Application number: PCT/US2005/024355
Authority: WO
Inventors: Steven Joseph Petrillo; Martin Walter Zalite; Larry Scott Harmon; Ronald G. Martin
Original assignee: Ashland Inc.
Priority date: 2004-07-08
Filing date: 2005-07-08
Publication date: 2006-01-26
Also published as: WO2006010043A3

Abstract

A system and method for pathogen control in reprocessing of foods are disclosed. The system and method use chlorine dioxide to eliminate pathogens from carcasses as the carcasses are passed through a spray cabinet.

Description

SYSTEM AND METHOD FOR PATHOGEN CONTROL IN REPROCESSING OF

FOODS

BACKGROUND

[01] This application claims the benefit of U.S. provisional application no.

60/585,860, filed July 8, 2004.

[02] Technical Field

[03] The technical field relates to the use of chlorine dioxide to eliminate pathogens from carcasses.

[04] Related Art

[05] Freshly slaughtered poultry or other meat products are contaminated with pathogenic microorganisms. The microorganisms are present on the surfaces of the animals and in the intestinal tracts immediately after slaughter or evisceration. A number of conventional processes employing biocides for pathogen control have been proposed to decontaminate the chill water used to process poultry and other meat products. These processes include the use of chlorine-based sanitizers, chlorine dioxide, acidified sodium chlorite solutions, ozone and peracetic acid. There are, however, problems associated with using these chemicals. Ozone has poor persistence, for example, while peracetic acid is only effective in high doses.

[06] U.S. Patent 5,389,390 discloses a process for removing bacteria from poultry using an aqueous solution containing about 0.001% to about 0.2% by weight of a metal chlorite, such that the chlorite ion is in the form of chlorous acid. While this process is capable of controlling some of the microorganisms in the chill water, it does not provide flexibility with applying the metal chlorite as the demand of the treated water increases. In addition, chlorous acid is not as effective some other agents in reducing pathogenic organisms such as salmonella and E. coli. [07] U.S. Patent 6,063,425 teaches a method for spraying carcass surfaces with acidified chlorite solution. It was hoped that the poultry/red meat would be either disinfected before entering the chiller bath, or that the level of surface organisms would be markedly reduced. It improved upon the teachings of the '390 patent by specifying the acid to be used as well as acidifying the chlorite/acid molar ratio. This teaching, however, suffered from many of the problems described above in the '390 patent.

BRIEF SUMMARY

[08] A method and system for processing carcasses are provided. The method and system use chlorine dioxide to eliminate pathogens from carcasses.

[09] According to one embodiment, a method of processing carcasses comprises: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling the amount of chlorine dioxide provided to the spray cabinet based on data from one or more sensors.

[010] According to another embodiment, a method of processing carcasses comprises: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting the presence or absence of a carcass on a shackle line.

[011] According to another embodiment, a method of processing carcasses comprises: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting the concentration of chlorine dioxide in air.

[012] According to another embodiment, a method of processing carcasses comprises: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling the operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting a chlorine dioxide level in residual drip from the carcasses.

[013] According to another embodiment, a system for reprocessing carcasses comprises: a spray cabinet having a plurality of spray nozzles arranged in the cabinet to spray carcasses with a chlorine dioxide solution; at least one controller operatively connected to a source of chlorine dioxide solution, the controller being arranged to control the flow of chlorine dioxide solution to the spray cabinet; and one or more sensors operatively connected to the at least one controller, the one or more sensors being arranged to sense operational parameters of the system.

[014] Further features and advantages of the invention will be apparent from the following detailed description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[015] The detailed description will refer to the following drawings, wherein like numerals refer to like elements, and wherein:

[016] FIG. 1 is a schematic diagram of a system for processing poultry according to an embodiment of the invention; [017] FIG. 2 A is a sectional view in side elevation of a spray cabinet of the system illustrated in FIG. 1;

[018] FIG. 2B is a front view of the spray cabinet illustrated in FIG. 1; and

[019] FIG. 3 is a schematic view of a chlorine dioxide supply system of the system illustrated in FIG. 1.

DETAILED DESCRIPTION

[020] FIG. 1 is a schematic view of a system 1000 for reprocessing foods. The system

1000 applies a controlled aqueous stream of chorine dioxide solution though a spraying system. The system 1000 contains emanating chlorine dioxide gas while simultaneously providing coverage of carcasses with the chlorine dioxide solution. The residual level of chlorine dioxide in the spraying waste stream may also be monitored and controlled. The system 1000 may be used to treat poultry carcasses, meat, fish, and other animal products or carcasses, hi this specification, for the sake of illustration, reprocessing operations are discussed with reference to poultry reprocessing. Other meats, fish, and animal products may also be treated according to the embodiments described in this specification.

[021] The application of chlorine dioxide in poultry processing is regulated by both the

Food and Drug Administration (FDA) and the Food Safety and Inspection Service (FSIS) of the US Department of Agriculture (USDA). Chlorine dioxide is approved for use in poultry chill water as stated in FSIS directive 6355.1 (09/23/96), and as directed in FDA 21 CFR 173.300. The FDA regulation (21 CFR 173.69) approving chlorine dioxide for use in poultry chill water became effective March 3, 1995. This section was redesignated as 21 CFR 173.300 in 1996. The USDA issued FSIS Directive 6355.1 on the use of chlorine dioxide in poultry chill water on September 23, 1996. The final rule approves up to 3 parts per million (ppm) residual chlorine dioxide to control microbial populations in poultry chill water contacting whole fresh poultry carcasses. [022] Referring to FIG. 1, the system 1000 comprises a spray cabinet 100, a residual drip collector 200, a controller 300, sensors 310, 320, 330, and a chlorine dioxide solution supply system 400. In general operation, poultry carcasses (not shown in FIG. 1) enter the spray cabinet 100 from the left, in the direction of the arrow. The carcasses may be conveyed on, for example, a shackle line (not shown), and may be processed in stages such as inside/outside bird washing, scalding, evisceration, and inside/outside feather removal, before entering the spray cabinet 100. The shackle line can be a continuous structure that conveys carcasses into, through, and out of the system 1000. The controller 300 controls various aspect of the system and is discussed in detail below.

[023] The spray cabinet 100 applies water and chlorine dioxide solution to poultry carcasses C. FIG. 2 A is a sectional view in side elevation of the spray cabinet 100, taken on line 2A-2A in FIG. 2B. FIG. 2B is a front view of the spray cabinet 100. Carcasses C move through the spray cabinet 100 from right to left in FIG. 2 A. The spray cabinet 100 includes a water spray line 110 having a plurality of nozzles 112. An input 114 of the water spray line 110 is connected to a source of water (not shown), and is used to apply a first uniform spray of water to carcasses C entering the spray cabinet 100. The water spray line 110 rinses the carcasses C with a high pressure, sweeping action potable water spray.

[024] A recirculation line 120 is located at a point in the cabinet 100 to apply recirculated chlorine dioxide solution to the carcasses C, after the water spray is applied. An input 122 of the recirculation line 120 receives recirculated solution from a recirculation system 130, located below the upper portion of the spray cabinet 100. The recirculated chlorine dioxide can be applied through an output 124 of the recirculation line 120 in the form of a dousing or "deluge" flow. Additionally, the recirculated chlorine dioxide solution can be applied to other carcasses and/or distributed to other parts of the system 1000.

[025] Chlorine dioxide solution lines 150 having spray nozzles 152 are located in the cabinet 100 to apply chlorine dioxide solution in spray form after the recirculated solution is applied. The chlorine dioxide solution lines 150 are shown as having a common input 156, although separate inputs can be used. The recirculation line 120 and the chlorine dioxide solution line 150 apply chlorine dioxide solution over the inner and outer areas of the carcasses C.

[026] During the spraying operation, runoff chlorine dioxide solution and water from the lines 110, 120, 150 falls into a collection pan or weir 134. The weir 134 includes a drain 142 that connects to an input 136 of the recirculation system 130, where the drained solution and water enters the recirculation system 130. The recirculation system 130 includes a tank 138 with a screen 140 that is used to filter out solids from the drainage from the weir 134. The unused part of the runoff flow exits through a drain 142, and the remainder is recirculated through a line 144. The recirculated flow is brought to pressure by a pump 146 and flows upward into the input 122 of the recirculation line 120. The pump 146 may include a control box 148 for controlling various functions of the pump 146.

[027] In the embodiment illustrated in FIGS. 2A and 2B, approximately 60-70% of the water and solution applied to the carcasses is recirculated by the system 130. This recirculation of chlorine dioxide solution is advantageous' because the chlorine dioxide source 400 is not required to provide all of the chlorine dioxide, and efficiency of chlorine dioxide conversion is improved. Further, the amount of waste chloride dioxide is minimized, and the chlorine dioxide waste is of reduced concentration.

[028] Referring back to FIG. 1, chlorine dioxide solution is supplied by the chlorine dioxide solution supply system 400. The chlorine dioxide supply system 400 includes chlorine dioxide generators 410 connected to a intermediate makedown and dilution system 412, which is connected to a feed and control skid 430. The feed and control skid 430 controls the flow of chlorine dioxide solution from the intermediate makedown dilution system 412. The chlorine dioxide solution is then routed through the controller 300, which may include valves and other control mechanisms to control the flow of chlorine dioxide solution to the input 156 of the chlorine dioxide solution lines 150 (shown in FIGS. 2A and 2B). A source of high pressure water can also be routed through the control panel 300. The control panel 300 can include valves and/or other control mechanisms to provide a high pressure stream of water to the input 114 of the water spray line 112.

[029] FIG. 3 is a schematic view of the chlorine dioxide solution supply system 400.

As shown in FIG. 3, the chlorine dioxide generators 410 empty into the intermediate makedown dilution system 412. Water for dilution of the chlorine dioxide, or "makedown water," can be added to the intermediate makedown dilution system 412 so that a first dilution occurs in the system 412. After dilution, chlorine dioxide can be present in water at a concentration of about 400-700 ppm, for example. In FIG. 3, "LT" indicates a level transmitter, "LE" indicates a level element, "S" indicates a solenoid, "FC" indicates a flow control, "FI" indicates flow indicator, and "FE" indicates a flow element.

[030] The operative elements of the feed and control skid 430 are indicated by outline in FIG. 3. The feed and control skid 430 regulates the flow of chlorine dioxide solution from the intermediate makedown dilution system 412, and can also regulate the flow of solution to chillers and/or pre-chillers (not illustrated) used in a subsequent part or processing. Pumps 416 are included to pressurize the chlorine dioxide solution for delivery to separate sets 420, 432 of feed valves. The set of feed valves 432 regulates the flow of chlorine dioxide solution to the control panel 300 (FIG. 1), which eventually is supplied to the chlorine dioxide solution lines 150 (FIGS. 2A, 2B).

[031] The chlorine dioxide solution from the storage tank 412 can be further diluted with water in the feed and control skid 430. For example, water can be introduced at the set of feed valves 432. The second stage of dilution can reduce the quantity of chlorine dioxide in solution to a range of about 50-250 ppm. More preferably, the quantity of chlorine dioxide in solution is 125-250 ppm after the second stage of dilution. [032]

[033] Referring back to FIG. 1, the residual drip collector 200 is located at the exit of the spray cabinet 100. The residual drip collector 200 collects liquid chlorine dioxide and water that drips from the surface of poultry carcasses after decontamination of the carcasses in the spray cabinet 100. The residual drip collector 200 may be spaced, below the path of the shackle line, from the exit of the spray cabinet 100 by a distance of about 6- 7 feet. The residual drip collector 200 may be a drip tray system and may be located about one foot below the carcasses carried by the shackle line.

[034] The sensor 310 can represent a plurality of sensors. For example, a chlorine dioxide level sensor may be included for detecting chlorine dioxide levels on the carcasses after they have left the spray cabinet 100. An ORP sensor may also be included to sense oxidation/reductive potential in the residual solution, which may in turn be used to determine chlorine dioxide levels in the residual. The chlorine dioxide levels detected by the various sensors are used by the controller 300 in order to monitor chlorine dioxide residual levels to ensure they remain within industry standards, and for other purposes.

[035] The chlorine dioxide sensor and ORP sensor can be used to take automated online measurements while the shackle line conveys carcasses through the spray cabinet 100. Alternatively, the chlorine dioxide sensor and ORP sensor can be operated off line. Offline measurements can be taken by, for example, a DPD (NN-diethyl-P-phenyline diamine) sensor, and by photometric methods. Online measurements can be, for example, empirometric, and may be automated. The ORP and chlorine dioxide sensors may include water flush systems to clear contaminants.

[036] The controller 300, feed and control skid 430, and the sensors 310, 320, 330, are used to control various aspects of the system 1000, including the supply and concentration of chlorine dioxide solution from the source 400. The controller 300 may be a control panel, such as an Operator Interface Terminal (OIT), having controls for controlling various aspects of the decontamination process. The controller 300 may also include, for example, a processor, and/or one or more Programmable Logic Controllers (PLC) arranged to control all or a part of the operation of the system 1000. Further, valves and other mechanisms can be included as part of the controller 300, and may be mounted on a chemical metering skid that is operatively connected to the OIT. These mechanisms can be used to control the flow of water and chlorine dioxide solution to the spray cabinet 100.

[037] One function of the controller 300 is to monitor the environment in the workspace for the presence of chlorine dioxide. The sensors 320 and 330 may be used, for example, to monitor chlorine dioxide in air for levels that exceed industry standards, and to forward that data to the controller 300. Upon detection of excessive chlorine dioxide levels, the controller 300 can activate an alarm, and shut down the supply of chlorine dioxide to the spray cabinet 100, or take other actions to ensure the safety of workers. For example, when the concentration of chlorine dioxide in air in the workspace environment exceeds about .3 ppm, the controller 300 can shut down the chlorine dioxide spray and activate an audio and/or visual alarm. The location of the sensors 320 and 330 is exemplary, and any number of sensors can be employed at any location of the workspace. Alternatively, data from one or more of the sensors 320, 330 can be forwarded directly to the feed and control skid 430, which may adjust the chlorine dioxide solution, or stop the supply of chlorine dioxide solution.

[038] Operational sensors may also be included that measure flow rate or volume, flow pressure, chorine dioxide concentration, and other properties of the water and chlorine dioxide solution regulated by the controller 300. hi general, the operational sensors can be , used to detect operational parameters that fall outside of acceptable ranges. If such a parameter is detected, the data can be used by the controller 300 to correct the error. For example, an external input may be provided from, for example, an optical sensor to the feed and control skid 430 defining the rate of feed (or speed) of carcasses on the shackle line. The feed and control skid 430 can then determine the required flow, pressure and chlorine dioxide concentrations for the chlorine dioxide solution as a factor of the speed of shackle line, the size and/or type of carcasses, and the chlorine dioxide levels sensed in the residual drip. If residual chlorine dioxide levels are out of desire range, the controller 300 can immediately increase or decrease level of chlorine dioxide.

[039] A carcass sensor 500 may also be provided adjacent to the shackle line. The sensor 500 may be, for example, an optical sensor, and may be used to determine the presence or absence of a carcass on the shackle line. Any placement of the sensor 500 is acceptable so long as carcasses maybe detected before entering the spray cabinet 100. The sensor 500 can be located, for example, a predetermined distance prior to cabinet 100 along the shackle line. Data from the carcass sensor 500 can be used by the controller 300 to activate the spray cabinet 100 when a carcass is detected as approaching the spray cabinet 100. Alternatively, if the spray cabinet 100 is activated, and the absence of approaching carcasses is detected, the signal to the feed and control skid 430 can be used to stop the supply of chlorine dioxide solution to the spray cabinet 100. The sensor 500 may be located at shackle line height.

[040] The PLC and OIT of the controller 300 allow tracking of historical data for the various functions of the spray cabinet 100. For example, chlorine dioxide residual, cabinet spray pressure, water volume flow, chlorine dioxide levels in air, and chlorine dioxide concentrations in solution at each phase of production, can be tracked. The controller 300 can record, for example, on a 10-second interval all operating parameters of the entire system 1000.

[041] According to the above embodiments, the application of chlorine dioxide as an antimicrobial agent allows a continuous flow of carcasses to a chiller system without the requirement of manual reprocessing. [042] The system 1000 minimizes the effects of potentially pathogenic microorganisms typically present in food processing. This is accomplished by safely applying water treated with a controlled concentration of chlorine dioxide to carcasses.

[043] The system 1000 also provides added safety for operators because chlorine dioxide production can be reduced or eliminated if unsafe levels in air are detected.

[044] The foregoing description of the invention illustrates and describes the present invention. Additionally, the disclosure shows and describes only selected preferred embodiments of the invention, but it is to be understood that the invention is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings, and/or within the skill or knowledge of the relevant art.

[045] The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the invention. Accordingly, the description is not intended to limit the invention to the form disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments, not explicitly defined in the detailed description.

Claims

What is claimed is:

1. A method of processing carcasses, comprising: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling the amount of chlorine dioxide provided to the spray cabinet based on data from one or more sensors.

2. The method of claim 1, wherein the data from the one or more sensors comprises chlorine dioxide levels in residual drip from the carcasses.

3. The method of claim 1, wherein the data from the one or more sensors comprises an indication of the presence or absence of a carcass.

4. The method of claim 1, wherein the data from the one or more sensors comprises chlorine dioxide concentration in air.

5. The method of claim 1, wherein the data from the one or more sensors comprises at least one of the following: chlorine dioxide solution composition in solution, chlorine dioxide solution pressure, water pressure, chlorine dioxide solution flow rate, and water flow rate.

6. A method of processing carcasses, comprising: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting the presence or absence of a carcass on a shackle line.

7. A method of processing carcasses, comprising: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting the concentration of chlorine dioxide in air.

8. A method of processing carcasses, comprising: passing carcasses through a spray cabinet; spraying the carcasses in the cabinet with a chlorine dioxide solution; and controlling the operation of the spray cabinet based on input from at least one sensor, the at least one sensor detecting a chlorine dioxide level in residual drip from the carcasses.

9. The method of claim 14, wherein a controller controls operation of the spray cabinet by controlling the flow of chlorine dioxide to the spray cabinet.

10. A system for reprocessing carcasses, comprising: a spray cabinet having a plurality of spray nozzles arranged in the cabinet to spray carcasses with a chlorine dioxide solution; at least one controller operatively connected to a source of chlorine dioxide solution, the controller being arranged to control the flow of chlorine dioxide solution to the spray cabinet; and one or more sensors operatively connected to the at least one controller, the one or more sensors being arranged to sense operational parameters of the system.

11. The system of claim 10, comprising: a residual drip collector disposed to collect residual drip from the carcasses.

12. The system of claim 10, wherein the one or more sensors comprise at least one chlorine dioxide sensor at the residual drip collector.

13. The system of claim 10, wherein the one or more sensors comprise at least one chlorine dioxide sensor arranged to detect chlorine dioxide levels in air.

14. The system of claim 10, wherein the one or more sensors comprise at least one sensor arranged to detect the presence or absence of a carcass.

15. The system of claim 10, wherein the one or more sensors comprise sensors arranged to detect at least one of the following: chlorine dioxide solution composition, pressure, and flow rate.