U.S. patent application number 11/981230 was filed with the patent office on 2009-08-20 for microwave poultry processing device and method.
Invention is credited to Edgar Garcia-Rill, Drew Horst.
Application Number | 20090209187 11/981230 |
Document ID | / |
Family ID | 40272521 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090209187 |
Kind Code |
A1 |
Horst; Drew ; et
al. |
August 20, 2009 |
Microwave poultry processing device and method
Abstract
The invention relates to a method for loosening the feathers of
a fowl prior to killing and processing, by exposing the fowl to a
radio frequency source producing a frequency from between
approximately 5 GHz and approximately 40 GHz, with an average power
density from between approximately 10 mW per square centimeter and
approximately 100 mW per square centimeter, for a predetermined
period of time. The invention also relates to a method for killing
bacteria on the fowl prior to killing and processing.
Inventors: |
Horst; Drew; (Lampe, MO)
; Garcia-Rill; Edgar; (Little Rock, AR) |
Correspondence
Address: |
LATHROP & GAGE LLP
1845 S. NATIONAL, P.O. BOX 4288
SPRINGFIELD
MO
65808-4288
US
|
Family ID: |
40272521 |
Appl. No.: |
11/981230 |
Filed: |
October 31, 2007 |
Current U.S.
Class: |
452/86 |
Current CPC
Class: |
A23B 4/01 20130101; A22C
21/0061 20130101 |
Class at
Publication: |
452/86 |
International
Class: |
A22C 21/02 20060101
A22C021/02; A22C 21/00 20060101 A22C021/00 |
Claims
1. A microwave poultry processing device for sterilizing a fowl
comprising: a radio frequency source generating a radio frequency
field; wherein, the fowl is placed in proximity to the radio
frequency field for a predetermined period of time for killing
bacteria present on the fowl.
2. The device of claim 1 further comprising at least one field
guiding structure connected to the radio frequency source to limit
the spatial range of the radio frequency field.
3. The device of claim 1 wherein the radio frequency field has a
frequency between approximately 5 GHz and approximately 40 GHz.
4. The device of claim 1 wherein the radio frequency field has an
average power density between approximately 10 mW per square
centimeter and approximately 100 mW per square centimeter.
5. The device of claim 1 wherein the bacteria present within the
flesh of the fowl are killed.
6. The device of claim 1 wherein the predetermined period of time
is between 3 and 30 seconds.
7. A method for sterilizing a fowl comprising the steps of:
generating a radio frequency field; and exposing a body of the fowl
to the radio frequency field by placing the body adjacent the radio
frequency field for a predetermined period of time.
8. The method of claim 7 wherein the predetermined period of time
is between approximately 2 seconds and approximately 30
seconds.
9. The method of claim 7 wherein the radio frequency field has a
frequency between 5 GHz and approximately 40 GHz.
10. The method of claim 7 wherein the radio frequency field has an
average power density from between approximately 10 mW per square
centimeter and approximately 100 mW per square centimeter
11. The method of claim 7 further comprising directing the radio
frequency along at least one field guiding structure.
12. A method for depiliating a fowl comprising the steps of:
generating a radio frequency field; exposing the fowl to the radio
frequency field to loosen the feathers; and removing the loosened
feathers from the fowl.
13. The method of claim 12 further comprising placing the body of
the fowl adjacent to at least one field guiding structure for a
predetermined period of time.
14. The method of claim 13 wherein the predetermined period of time
is at least 2 seconds.
15. The method of claim 13 wherein the predetermined period of time
is between approximately 2 and approximately 30 seconds.
16. The method of claim 12 wherein the radio frequency field has a
frequency between approximately 5 GHz and approximately 40 GHz.
17. The method of claim 12 wherein the radio frequency field has an
average power density between approximately 10 mW per square
centimeter and approximately 100 mW per square centimeter.
18. The method of claim 12 further comprising directing the radio
frequency along at least one field guiding structure.
19. The method of claim 12 wherein the step of removing the
feathers is achieved by a process selected from the group
consisting of: pulling, plucking, blowing, or suctioning.
20. The method of claim 12 wherein the radio frequency field has an
average power density sufficient to degrade a protein strand
securing a feather quill within a follicle.
21. The method of claim 12 wherein the duration of exposure to the
radio frequency field is sufficient to degrade a protein strand
securing a feather quill within a follicle.
Description
FIELD OF THE INVENTION
[0001] 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 within the follicle prior to
another processing step for removing the feathers.
BACKGROUND OF THE INVENTION
[0002] 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.
[0003] 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 bacteria. Multiple washing steps may also be used to reduce
bacterial contamination during processing by washing the poultry
carcasses after each processing step.
[0004] An example of control techniques for bacterial
contamination, U.S. Pat. No. 6,547,659 to Adachi et al., describes
the use of multiple rinsing steps during processing, and a
sterilizing step where poultry carcasses are 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.
[0005] It is recognized that killing or preventing bacterial
contamination at an early stage of processing is preferred. The
current methods of decontaminating the poultry carcasses are
insufficient in 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 occur later in
the processing process, after processing has opened the bird and
exposed the meat of the poultry to the bacterial contamination.
[0006] The poultry processing device and method described in this
application provide for decontamination from bacteria at a very
early stage in the processing, before the poultry has been killed
or cut open in any way. Further, the microwaves used to
decontaminate the poultry may reach all areas of the carcass
without the limitations of a water-borne treatment, which may not
effectively contact all areas of the carcass. The poultry
processing device described herein is non-invasive and can be
utilized on live poultry without causing pain or damage to the
animal.
[0007] 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 in hot water to scald the poultry
carcass, thereby causing the feather follicles in the skin of the
carcass to dilate or 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 organs with water if the
poultry is still alive. The inventive device and method disclosed
herein loosens feather quills from the associated follicle by
degrading the protein strand which secures the feather in the
follicle. Once the quill is loosened in the follicle, feathers may
be dislodged by force, such as hand or machine plucking, or with
jets of compressed air.
[0008] The processing device and method described herein provide
for the loosening of feathers by exposure of the chicken carcass to
radio frequency electromagnetic radiation, without the problems
caused by the existing methods of loosening feathers.
BRIEF DESCRIPTION OF THE DRAWING
[0009] The invention is illustrated using the following figures
along with the detailed description of the invention.
[0010] FIG. 1 is a perspective view of an embodiment of the
inventive device.
[0011] FIG. 2 is a cross sectional view taken along line 2-2 of
FIG. 1; and
[0012] FIG. 3 is a cross section view, according to an embodiment,
of a roller belt assembly for conveyance of the poultry.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The microwave poultry processing device and method described
herein relates to a new device and method for reducing and killing
bacteria in poultry during processing. The device further relates
to an improved method and process for depilliating poultry
carcasses.
[0014] Referring generally now to FIG. 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 present on and
within the flesh of 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
parameters of the power generation, exposure time, and the like
discussed below. In one embodiment, field guiding structure 101 is
either coated with an easily cleaned surface or provided with a
shield that can be removed for cleaning.
[0015] Integrated with the field guiding structure 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 structure 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.
[0016] A radio frequency coupling trough 107, through which RF
(radio frequency) signals can be coupled into field guiding
structure 101, may use antennas, apertures, probes, wires, or other
methods commonly practiced in the art of microwave RF design for
concentrating an RF signal or RF field, and reducing power
requirements. 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 are
mounted through apertures in one or more parallel guiding plates.
These troughs 107 are connected to a source 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) within the field guiding
structure 101 prior 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 in 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 structure
101 to prevent electrical arcing which would result in undesired
heating of the conveying system 113.
[0017] 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
incapacitator 100. A frequency range of from between 5 (gigahertz)
GHz to 40 GHz can operatively kill bacteria on the fowl and loosen
the feathers of the fowl, depending on power density. In at least
one embodiment, the RF frequency is approximately 16 GHz, which is
typical of Ku band microwave applications. The peak power rating is
in the range of 10 kilowatts (kW) to 100 kW. In one embodiment, the
optimum peak power rating is 60 kW, with an average power in the
range of 20 W to 200 W, preferably 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%.
[0018] Magnetron tubes consistent with the above specifications are
commercially available and are manufactured, for example, by CPI
Wireless Solutions of Beverly, Mass. An exposure energy density of
between 150 milliwatts (mW) seconds per square centimeter and 350
mW seconds per square centimeter is sufficient to substantially
reduce common bacteria present on the animals 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 eradicate common
bacteria from the animal carcass in approximately 2 to 10
seconds.
[0019] 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 centimeter and
approximately 100 mW per square centimeter, produced and
concentrated within 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 within field guiding structure 101 for a period
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 within 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, or multiple
magnetrons can be used in series to provide RF exposure at multiple
points along field guiding structure 101.
[0020] In another embodiment, as shown in FIG. 3, the same method
or process of exposing the animal's body to RF is used while the
animals are standing or resting on a surface, such as a conveyor
115, with the RF signals transmitted generally downward towards the
head or from the side towards the body and head. Conveyor 115 may
be a roller belt assembly or other conveyor system well known in
the art. The device described herein is also useful for aiding in
the depilliating of poultry during processing. There are two basic
types of feather: vaned feathers which cover the exterior of the
body, and down feathers which are underneath the vaned feathers.
The pennaceous feathers are vaned feathers. Also called contour
feathers, pennaceous feathers are distributed over the whole body.
Some of them are modified into remiges, the flight feathers of the
wing, and rectrices, the flight feathers of the tail. A typical
vaned feather features a main shaft, called the rachis. Fused to
the rachis are a series of branches, or barbs; the barbs themselves
are also branched and form the barbules. These barbules have minute
hooks called barbicels for cross-attachment. Down feathers are
fluffy because they lack barbicels, so the barbules float free of
each other, allowing the down to trap much air and provide
excellent thermal insulation. At the base of the feather, the
rachis expands to form the hollow tubular calamus, or quill, which
inserts into a follicle in the bird's skin.
[0021] The device aids in the poultry-depilliating process by
causing the follicles in the skin of the poultry to dilate or
otherwise open, thus loosening the attachment between the feathers
and the flesh. Further, one or more strands or protein connect the
quill and the follicle. Exposure of the carcass to RF, as described
herein, causes the protein strand(s) to degrade. Sufficient RF
exposure will actually liquify the protein which allows the feather
to easily be removed from the follicle. Once the feathers have been
loosened in 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 carcass is
processed according to any of the well-known methods of removing
feathers such as by hand, by machine plucking, by exposure to jets
of compressed air, or by suctioning, among others.
[0022] Methods of removing feathers known in the art will be less
efficient and take more time to remove the same amount of feathers
from a carcass than that which 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 depilliating process will make the
complete carcass processing method more efficient, less wasteful,
and increase the quality of the final product. Further, this method
saves substantial money. Feathers removed from carcasses are used
for any number of purposes, from bedding and clothing to animal
food additives, insulation or other durable consumer goods.
Currently, feathers removed during the slaughter process are
typically wet from the traditional scalding method. The wet
feathers are heavy and difficult to move. Further, wet feathers
have a foul odor and may become mildewed or moldy if not dried in a
reasonable amount of time. The instant method allows dry feathers
to be transported and processed, saving in transportation and
processing costs.
[0023] The inventive process utilizes 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 in approximately 2 to 10
seconds.
[0024] 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 spirit or scope
of the invention. The present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *