Meat decontamination

The invention relates to decontaminating meat by locating a body of meat (10) within a chamber (15), providing a volume (25) of decontaminating water (27) sufficient to fill the chamber (15) and immerse the body of meat; supplying the decontaminating water (27) at e.g. 80.degree. C. to the chamber at multiple inlet point (31-34) accompanied by substantial turbulence as it fills the chamber (15) and discharging the decontaminating water from the chamber (15) after the body of meat (10) has been decontaminated (e.g. after ten seconds). The volume of decontaminating water (27) is provided in an elevated vessel (26) connected to the chamber (15) through a supply passage (30) of relatively large flow area. The body of meat (10) is suspended from an overhead conveyor (11) and is conveyed into the chamber (15) through an entry opening and out of the chamber (15) through an exit opening, the body of meat (10) being paused in its movement by the conveyor (11) when it has entered the chamber (15) to enable the decontaminating operation to take place.

This invention relates to a process and apparatus for decontamination of 
meat. 
After a carcass of a slaughtered animal has passed through a number of 
physical processing stages in an abattoir, such as head removal, hide or 
pelt removal, evisceration, and carcass splitting, the carcass is usually 
moved to a chiller or cool room for temporary or medium term storage. 
Although processes and operations are carried out in a manner to minimise 
bacterial contamination, nevertheless the considerable handling and 
processing does result in surface contamination by micro-organisms from 
airborne micro-organisms and from contact with human operators, with other 
carcasses, and with apparatus. Hence, before taking a carcass to the 
storage facility, the carcass is decontaminated. 
In the past, decontamination of carcasses has been carried out by a washing 
operation. For example, the carcass can pass by an installation where 
fixed sprays are located, the carcass being sprayed with a washing 
solution, such as an acetic acid solution, chlorine solution, or solution 
of other disinfectant or anti-microbial agent. Another known system, 
instead of using sprays of a decontaminating solution, uses a flume or 
curtain of falling solution through which the carcass passes so that the 
solution runs down and washes the surface of the carcass. It has also been 
proposed to use nozzles to direct steam at the carcass to contact and 
decontaminate the surface, or to enclose the carcass in a steam cabinet. 
The known decontamination systems can suffer from a number of 
disadvantages. In particular, it can be difficult to design and construct 
installations where the treatment solution or steam contacts substantially 
the entire surface area of the carcass. This can result in significant 
areas of a carcass potentially contaminated with micro-organisms not being 
effectively decontaminated. Also, the use of solutions of anti-microbial 
agents can have particular problems, e.g. an acetic acid solution causes 
corrosion problems with metal components that can be contacted by the 
solution. Chemical tainting of carcasses can also be a potential problem. 
Steam decontamination can cause safety hazards for human operators. 
It is an object of the present invention to provide a process and apparatus 
for decontamination of meat which is effective in operation. 
It is a preferred object of the present invention to provide a process and 
apparatus for decontamination of meat which can alleviate some or all of 
the problems with prior decontamination systems outlined above. 
According to the present invention there is provided a process of 
decontaminating meat including the steps of: 
locating a body of meat within a chamber; 
providing a volume of decontaminating water sufficient to fill the chamber 
to a level sufficient to immerse the body of meat; 
selectively supplying the decontaminating water to the chamber so that the 
decontaminating water rapidly enters the chamber to immerse the meat, 
creating substantial turbulence in the decontaminating water as it fills 
the chamber; and 
discharging the decontaminating water from the chamber after the body of 
meat has been decontaminated. 
By rapidly introducing into the chamber a volume of liquid sufficient to 
totally immerse the body of meat, there is substantial turbulence created 
in the decontaminating water entering the chamber. The turbulence of the 
water and bubbles in the water promotes effective contact between the 
decontaminating water and the surface area of the body of meat so that the 
decontaminating action of the water can be effectively achieved over the 
entire surface area. This action includes the physical removal of 
micro-organisms from the surface and collection in the water. 
The volume of decontaminating water may be provided in a vessel in an 
elevated position relative to the chamber, the vessel being connected to 
the chamber through a supply passage of relatively large flow area so that 
the, volume of decontaminating water can flow quickly from the vessel into 
the chamber. The body of meat is preferably suspended from an overhead 
conveyor and is conveyed into the chamber through an entry opening and out 
of the chamber through an exit opening by movement of the body of meat 
along the conveyor, the body of meat being paused in its movement by the 
conveyor when it has entered the chamber through the entry opening to 
enable the decontaminating operation to take place and subsequently the 
movement by the conveyor being resumed to move the body of meat out 
through the exit opening. 
It has been found that it is effective to use decontaminating water at a 
temperature of about 80.degree. C. with the body of meat is immersed in 
the heated water for about 10 seconds or more, and these process 
parameters are preferred. 
The present invention also provides an apparatus for decontamination of 
meat including: 
a chamber in which a body of meat is located; 
a supply which holds a volume of decontaminating water at least sufficient 
to fill the chamber to a level sufficient to immerse the body of meat; 
valve means which is selectively operable to connect the supply to the 
chamber so that the decontaminating water rapidly enters the chamber to 
immerse the body of meat, creating substantial turbulence upon entering 
the chamber; and 
a discharge selectively openable to empty the chamber after the body of 
meat has been decontaminated. 
In the preferred embodiment, the chamber includes a cabinet having an entry 
opening and an exit opening through which the body of meat is conveyed 
into and out of the chamber, the entry opening and exit opening having 
respective associated closures which are closed when the decontaminating 
operation is taking place and which are opened respectively to allow the 
body of meat to be conveyed into and to be conveyed out of the cabinet. 
The apparatus preferably further includes an overhead conveyor from which 
the body of meat is suspended, the overhead conveyor being operative to 
convey the body of meat through the entry opening prior to the 
decontaminating operation and to convey the body of meat out through the 
exit opening after completion of the decontaminating operation in the 
cabinet. The conveyor preferably has associated means operative to stop or 
pause the movement of the body of meat within the cabinet to enable the 
decontaminating operation within the cabinet to take place, and to resume 
movement of the body of meat after the decontaminating operation. 
The supply may include an elevated vessel in which there is stored a volume 
of decontaminating water at least sufficient to fill the chamber to a 
level to immerse the body of meat and a supply passage extending from the 
vessel to the chamber, the supply passage having a substantial 
cross-sectional flow area so that the volume of decontaminating water can 
flow quickly from the vessel into the chamber. The supply passage from the 
vessel to the chamber preferably opens into the chamber at a number of 
points within the chamber so as to introduce the water at different 
heights and/or from different directions so as to thereby enhance the 
turbulence created as the water is introduced. 
The discharge may include a discharge located in the floor of the chamber 
so that at the end of the decontaminating operation, the water in the 
chamber can be dumped rapidly out through the bottom of the chamber. 
The apparatus preferably further includes heating means to heat the 
decontaminating water to a predetermined temperature, and a control means 
to control the decontaminating operation including control of the entry 
into and exit from the chamber of the body of meat, the heating of the 
water to the predetermined temperature, the opening of the valve means to 
connect the supply to the chamber, and the opening of the discharge to 
empty the chamber at the end of the decontaminating operation.

The illustrated apparatus shows a body of meat 10 namely a side of beef 
suspended from an overhead conveyor 11. The apparatus has been 
particularly designed and developed for beef carcasses but is useable with 
other species such as ovine carcasses and with other meat portions. 
The apparatus includes a chamber 15 defined by a cabinet 16 having entry 
and exit openings 17, 18 through which the body of meat 10 is conveyed 
into and out of the chamber 15. The entry and exit openings 17, 18 have 
respective associated closures 19, 20 which are closed when the 
decontaminating operation is taking place but which are opened 
respectively to allow the body of meat 10 to enter into and exit from the 
cabinet 15. The body of meat 10 may for example comprise a carcass (which 
expression includes a side of an entire carcass of a slaughtered animal, a 
forequarter, hindquarter, or other portion or body of meat) which can be 
suspended from the overhead conveyor 11 in a conventional manner using 
hook 12 movable along tail 13. The entry and exit openings 17, 18 are 
provided in respective opposite side walls of the cabinet 15 in the path 
of movement of the body of meat 10 determined by the conveyor 11. 
The apparatus includes a supply 25 including a header vessel 26 in which 
the volume of decontaminating water 27 at least sufficient to fill the 
chamber 15 to a level to immerse the meat is stored. Supply passage 30, 
shown as ducts or pipes, extends from the header vessel 26 to the chamber 
15, opening into the chamber at a number of points 31, 32, 33, 34 to 
introduce the water at different heights and from various directions, 
thereby enhancing the turbulence created as the water is introduced. The 
supply ducts 30 are of substantial cross sectional area so that the volume 
of decontaminating water can flow quickly from the header vessel 26 
through the ducts into the chamber 15 when the valve means 35 is opened. 
The valve means 35 preferably comprise rapidly opening valves which can 
open the supply ducts 30 or supply ports 31-34 into the chamber 15 to 
allow rapid flow therethrough, suitable valves being sliding or hinged or 
pivoted valve plates. 
A discharge 40 is selectively openable to empty the chamber 15. The 
illustrated discharge 40 is located in the floor 41 of the chamber 1 S. In 
the illustrated embodiment, the floor 14 itself is hinged along one edge 
42 and can be dropped away from its normally horizontal position in which 
it closes the bottom of the chamber 15 thereby dumping the water from the 
chamber rapidly out through the bottom, e.g. into a bottom collection tank 
45 located beneath the chamber. The bottom collection tank 45 can Function 
as a storage for decontaminating water, the apparatus also including pump 
means 46 to raise the water from the bottom collection and storage tank 45 
to the header vessel 26. 
If desired the decontaminating water 27 after discharge can be recycled. 
This can include filtering to remove particulate impurities or 
contaminants as well as chemical and/or biological treatment to make the 
recycled water suitable for reuse in a subsequent decontaminating 
operation. 
The decontaminating water 27 may incorporate disinfectant or anti-microbial 
agents such as chemical additives of the kinds used in the past. However 
it has been found that addition of anti-microbial agents need not be 
necessary if the water is heated to a suitable temperature for effecting 
bacteriological decontamination. For example, the water may be heated to a 
temperature of about 80.degree. C. and the chamber 15 containing the body 
of meat 10 filled with water at this temperature. 
The period of time that a body of meat is immersed in decontaminating water 
can also influence the effectiveness of the decontaminating operation. It 
has been found that immersion of a body of meat at 80.degree. C. for about 
ten seconds is effective to achieve acceptable micro-biological 
decontamination of a carcass. 
Heating means 47 are provided to heat the decontaminating water to a 
predetermined temperature. A control means 50 controls the decontaminating 
operation including control of the entry into and exit from the chamber 15 
of the body of meat 10, the heating of the water to the predetermined 
temperature, the opening of the valve means 35 to connect the supply 25 to 
the chamber, and the opening of the discharge 40 to empty the chamber at 
the end of the decontaminating operation. 
In operation of the apparatus, the carcass side 10 carried by the overhead 
conveyor 11 can enter the cabinet 16 through the entry opening 17. The 
conveyor 11 from which the carcass side is suspended can be stopped, or 
other mechanical systems can be used to pause the carcass in the 
decontamination cabinet 16 during treatment. The closure 18 associated 
with the entry opening 17 can be automatically closed, e.g. by sensing the 
passage of a carcass 10 into the chamber 15. The fill, soak and discharge 
cycle can then be automatically implemented. The water temperature, and 
soak time can be programmed and therefore can be variable as desired. As 
mentioned above, typically the carcass side is immersed for about ten 
seconds at 80.degree. C. After the decontaminating water is discharged, 
the closure 20 associated with the exit opening 18 of the cabinet 16 can 
be opened and the decontaminated carcass 10 can be automatically conveyed 
out of the cabinet through the exit opening. 
It will be seen that the process and apparatus according to the present 
invention can effectively decontaminate a body of meat located within the 
chamber. In particular, the rapid dumping of a volume of heated 
decontaminating water sufficient to fill the chamber to immerse the body 
of meat creates substantial turbulence in the chamber. The buffeting of 
the body of meat, the turbulence in the water, including the large 
quantities of air bubbles violently agitating the water, promote contact 
of the decontaminating water with the entire surface area of the body of 
meat, including concavities and crevices. Also, the temperature of the 
water and the immersion time will result in heating of the entire surface 
area, even in tiny air filled crevices where the decontaminating water may 
not have directly contacted, so that micro-organisms on the surface will 
be exposed to the elevated temperature.