MICROWAVE POULTRY PROCESSING DEVICE AND METHOD

RELATED APPLICATION

[0001] This application is a continuation-in-part and claims priority to U.S. Patent Application Serial Number 1 1/184,939, filed July 19, 2005, which claims priority to U.S. Patent Application Serial Number 11/026,932, filed December 31 , 2004, which claims priority to U.S. Provisional Patent Application Serial Number 60/533,489 filed December 31 , 2003. The aforementioned applications are incorporated by reference herein.

FIELD OF THE INVENTION [0002] The device and method disclosed herein relates generally to poultry processing, and in particular to a device and method utilizing radio frequencies, specifically microwaves, for killing bacteria on poultry during the processing of the poultry. The disclosed device and method also may be used to aid in depilliating poultry by loosening the feathers on poultry prior to another processing step for removing the feathers.

BACKGROUND OF THE INVENTION

[0003] The control of bacterial contamination is an important issue during the processing of poultry for human consumption. Cross-contamination of bacteria from one bird to another may be exacerbated by the mass processing of poultry and the use of automated production equipment. Operations such as chilling poultry carcasses in a chiller bath provide avenues for cross contamination through the use of a tank of chilled water that is reused to chill many poultry carcasses. Feather removal processing steps may also introduce bacteria onto the poultry from fecal matter originating in the poultry carcass' lower intestine. Secondary contamination sources, such as manual processing steps, may also create risks of bacteria contamination of poultry from handlers.

[0004] Current methods of removing bacteria from chickens may utilize chemical treatments to kill the bacteria. For example, the water in chiller baths used to lower the temperature of poultry during processing, may also be treated with chlorine, sodium hypochlorite or other chemical treatments known in the art to kill the

bacteiia Multiple washing steps may also be used to i educe bacteiial contamination during piocessmg by washing the poultiy caicasses aftei each piocessmg step

[0005] An example of contiol techniques foi bacteπal contamination, U S Patent 6,547,659 to Adachi et al , desciibes the use of multiple rinsing steps during processing, and a sterilizing step where poultiy caicasses aie sterilized during chilling in the chilled bath Sterilization in the chiller bath may include chlorine solutions, or other chemical solutions added to the bath to kill any bacteria present

[0006] It is recognized that killing or preventing bacteπal contamination at an early stage of processing is preferred The current methods of decontaminating the poultry carcasses are insufficient m that they are usually dependent on water-bourne chemicals or simple washing to remove bacteria Such washing or chemical bath methods are undesirable because the wash solution may become contaminated with bacteria when used to process multiple poultry carcasses, and thus may exacerbate the problem the methods were designed to resolve These washing steps also occui later m the processing piocess, aftei processing has opened the bud and exposed the meat of the poultry to the bacteπal contamination

[0007] The poulty piocessmg device and method desciibed in this application provide for decontamination from bacteiia at a veiy early stage in the processing, befoie the poultry has been killed or cut open in any way Furthei, the microwaves used to decontaminate the poultry may reach all aieas of the carcass without the limitations of a water-borne treatment, which may not come in contact with all areas of the carcass The poultry processing device described herein is noninvasive and can be utilized on live poultry without causing pam or damage to the animal [0008] The removal of feathers from poultry is also an important part of poultry processing Various methods for loosening the feathers prior to plucking have been developed, to provide for more complete feather removal One known method to loosen feathers is to submerge the poultry carcass m hot water to scald the poultry carcass, thereby causing the feather follicles m the skm of the carcass to open, thus loosening the feathers in the follicles This method has a number of disadvantages, such as poor feather removal unless scald bath temperature is uniform, discoloration of the carcass if the temperature of the scald bath is too high, and contamination of

internal oigans with watei if the poultiy is still ah\e Once loosened, featheis may be dislodged by foice, such as hand 01 machine plucking, 01 with jets of compi essed an

[0009J The piocessmg de\ice and method desciibed heiein provide foi the loosening of featheis by exposuie of the chicken caicass to radio frequency electromagnetic radiation, without the problems caused by the existing methods of loosening feathers

BRIEF DESCRIPTION OF THE DRAWING:

[0010] The invention is illustrated using the following figures along with the detailed description of the invention [0011] Figure 1 is a perspective view of an embodiment of the inventive device

[0012] Figure 2 is a cross sectional view taken along line 2-2 of Figure 1 , and

[0013] Figure 3 is a cioss section view, according to an embodiment, ot a rollei belt assembly for conveyance of the poultiy

DETAILED DESCRIPTION OF THE INVENTION:

[0014] The microwave poultry processing device and method described herein relates to a new device and method for reducing and killing bacteria m poultry during processing The device further relates to an improved method and process for depilliating poultry carcasses

[0015] Referring generally now to Figure 1, an embodiment of the poultry processing device 100 is presented In this particular embodiment, microwave radio frequency signals are transmitted along field guiding structures, e g structure 101, which limit the signal transmission range Exposure of the bacteria on and within the poultry to specific radio frequencies over a period of time will effectively kill a significant amount of the bacteria In at least one embodiment, the field guiding structure 101 is a metallic cylinder or tube The tube may be either fully or partially closed In yet another embodiment, the field guiding structure 101 includes a plurality of parallel guiding plates (not shown) In at least one embodiment, field guiding structure 101 is constructed from a highly conductive metal It may be necessary to curve the sides of field guiding structure 101, dependent upon the

parameteis of the powei geneiation, exposuie time, and the like discussed below In one embodiment field guiding structure 101 is eithei coated with an easily cleaned surface 01 piovided with a shield that can be iemo\ ed for cleaning

[0016J Integrated with the field guiding structuie 101 is a shackle line 103 In particular, shackle line 103 is positioned such that movement along shackle line 103 transports shackled poultry through field guiding structuie 101 at a predetermined rate Cross-referencing for a moment FIG 1 with FIG 2, animals (poultry) are suspended upside down by any of a number of retaining or shackling devices 105 well known in the art, and are conveyed along shackle line 103 with their bodies passing through field guiding structure 101

[0017J A radio frequency coupling trough 107, through which RF (radio frequency) signals can be coupled into field guiding structuie 101, may use antennas, apertures, probes, wnes, or other methods commonly practiced in the art of microwave RF design for concentrating an RF signal oi RF field, and i educing power lequnements A plurality of troughs 107 are positioned longitudinally along the length of field guiding structure 101, as shown in FIG 1 In at least one embodiment, troughs 107 aie mounted through apertures m one oi more paiallel guiding plates These troughs 107 are connected to a souice 109 of the RF signals through guiding structures that are known as waveguides, of which waveguide 111 is exemplary In yet another embodiment, other well known structures available for guiding electromagnetic waves at the frequencies described below may be used It may be beneficial to place a cylindrical resonator (not shown) withm the field guiding structure 101 pπor to passing a radio frequency along structure 101, to decrease the required operational power Further, a single radio frequency transmitter 108 (FIG 2) may be used m conjunction with a microwave power splitter (not shown) to convey power through a given trough 107 An overhead conveying system 113, which includes shackle line 103, is grounded to field guiding structuie 101 to prevent electπcal arcmg which would result in undesired heating of the conveying system 113 [0018] The RF power may be supplied by a klystron, magnetron, or similar device (not shown) consistent with the peak power rating, pulse repetition frequency, duty cycle and RF frequency required by mcapacitator 100 A frequency

iange of fiom between 5 (gigahertz) GHz to 40 GHz can opeiatively kill bacteiia on the fowl and loosen the featheis of the fowl, depending on powei density In at least one embodiment, the RF frequency is appioximately 16 GHz, which is typical of Ku band miciowave applications The peak powei rating is in the iange of 10 kilowatts (kW) to 100 kW In one embodiment, the optimum peak powei rating is 60 kW, with an average power m the range of 20 W to 200 W, pieferably 100 W It is understood that power ratings may differ depending on the usable configuration of the RF power supply Typically, the pulse frequency will be approximately 8400 Hz (+/-) 2500 Hz, with a pulse duration of approximately 0 20 microseconds This is commensurate with a duty cycle of approximately 0 2%

[0019] Magnetron tubes consistent with the above specifications are commercially available and are manufactured, for example, by CPI Wireless Solutions of Beverly, MA An exposure energy density of between 150 milliwatts (mW) seconds pei squaie centimeter and 350 mW seconds per square centimeter is sufficient to substantially reduce common bacteiia piesent on the animals at a power density of 45 mW per square centimetei The exposure time at this power level is m the range of 2 to 30 seconds, but will eradicate common bacteria from the animal carcass in approximately 2 to 10 seconds

[0020] In one embodiment of the inventive method, the following parameters are specified a radio frequency from between approximately 5 GHz and approximately 40 GHz, with an average power density from between approximately 10 mW per square centimetei and approximately 100 mW per square centimeter, produced and concentrated withm and/or around a field guiding structure, such as field guiding structure 101 An animal's, e g poultry, complete body is then exposed to the radio frequency by placing the animal's body adjacent to or withm field guiding structure 101 for a peπod of time from between approximately 3 seconds and approximately 30 seconds In at least one embodiment, the radio frequency is produced from a magnetron operable withm the Ku band In a second embodiment, the body of the standing, shackled and/or conveyed animal is exposed from above or from the sides with similar effects In those cases in which repeated exposure is desired, the waveguides, e g waveguide 111, can be split to provide RF at multiple

points along field guiding structure 101, 01 multiple magnetions can be used in series to provide RF exposme at multiple points along field guiding structure 101

|0021] In anothei embodiment, as shown in Figure 3, the same method oi process of exposing the animal ^' s body to RF is used while the animals aie standing or iestmg on a smface, such as a conveyoi 115, with the RF signals tiansmitted generally downward towards the head oi from the side towaids the body and head Conveyor 115 may be a roller belt assembly or other conveyor system well known m the art

[0022] The device described herein is also useful for aiding in the depilhatmg of poultiy during piocessmg The device aids in the poultry-depilhating process by causing the follicles m the skm of the poultry to open up, thus loosening the attachment between the feathers and the carcass Once the feathers have been loosened m the follicles, some may become disconnected from the poultry However, most feathers will remain loosely attached to the carcass To complete the depiliation process, the caicass is processed according to any of the well-known methods of lemovmg feathers such as by hand, by machine plucking, or by exposme to jets of compressed air, among others

[0023] Methods of lemovmg featheis known in the ait will be moie efficient and take less time to lemove the same amount of feathers from a carcass that has been processed according to the invention described herein The quality of the poultry carcass will be improved, as a higher percentage of feathers will be removed with less labor The improved depilhatmg process will make the complete carcass processing method more efficient, less wasteful, and increase the quality of the final product

[0024] An exposure energy density of between 150 milliwatts (mW) seconds per square centimeter and 350 mW seconds per square centimeter is sufficient to substantially loosen the feathers present on the poultry carcass at a power density of 45 mW per square centimeter The exposure time at this power level is in the range of 2 to 30 seconds, but will loosen the feathers attached to the animal carcass m approximately 2 to 10 seconds [0025] It will be apparent to those skilled in the art that various modifications and variations can be made in the system and method of the present invention without departing from the spiπt or scope of the invention The present

invention coveis the modifications and vaπations of this invention piovided they come within the scope of the appended claims and their equivalents