GB2526663A - Processing of poultry - Google Patents

Abstract

A method of decontaminating a poultry carcass comprises after a defeathering stage, but before an eviscerating stage, immersing the carcass in water heated in the range of 60 to 90°C for less than 20 seconds. The method may also comprise commercially processing poultry by continuously passing poultry carcasses along a processing line which comprises a scalding stage, a defeathering stage and an evisceration stage. The carcasses are immersed in water heated in the range of 60 to 90ºC between the defeathering and eviscerating stages. The process provides decontamination without the use of expensive ultrasonic equipment or chemical disinfectants. A decontamination station comprises a water tank (20) having a leading end (21) and an outlet trailing end (22). A conveying means (51) conveys poultry through the tank to immerse the poultry in the tanks for less than 20 seconds. The poultry has a longer residence time in the lead out portion of the tank than the lead portion to allow for drainage.

Description

PROCESSING OF POULTRY

This invention relates generally to food processing and preferably to the processing of poultry and poultry products. More specifically, although not exclusively, this invention relates to an improved method for the processing of poultry which reduces the bacterial loading on poultry, and preferably reduces the amount of bacteria remaining on poultry post-processing.

It is known within the food industry to process poultry via inline production processes wherein live poultry, hung by their ankles, are, in sequence, stunned, bled, scalded, defeathered, eviscerated and chilled. Downstream the carcass may be jointed or deboned dependent upon the nature of the final product required (Le. whole birds or poultry joints -legs, thigh, breasts etc.).

Poultry may be contaminated with bacteria, where the contamination is particularly found in the faecal matter of the poultry, and where the faecal matter may exist on the feathers, skin, etc. of the poultry. Numerous recent studies have found that poultry contaminated with bacteria may subsequently lead to human infection. The most prevalent bacteria associated with poultry and having a deleterious effect on human health are Campylobacter, Salmonella, Escherichia coli, Listeria monocytogenes and Staphylococcus. The prior art processing of poultry (as shown diagrammatically in Figure 1) affords plural opportunity for cross contamination of poultry carcasses. For example, the scalding tank may lead to cross contamination, and defeathering can lead to the generation of bacteria-loaded aerosols. As may be expected, many of the problematic bacteria are prevalent in the GI tract of poultry. In the circumstances, evisceration can lead to gut breakage and consequential inter-poultry transmission of bacteria.

The European Food Safety Authority (EFSA) reported in 2006 (in Campylobacter, The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial Resistance and Foodborne Outbreaks in the European Union in 2005, EFSA J 94) that European Union countries have experienced an increase in the number of reported cases of human infection by campylobacter since the early 1990s. Due to concern regarding human infection via contaminated poultry products there is an EU requirement, under Directive 2003/99/EC, that Campylobacter levels must be monitored prior, as well as subsequent to, the slaughter of poultry.

Consequently, a number of alterations to the known method of processing poultry have been proposed in order to reduce the levels of bacterial on poultry and poultry products which are to be sold in store.

US 5484615 describes a post-evisceration process to reduce the levels of microbial bacteria in processed poultry whereby the chilling process entails immersing the poultry carcasses in a disinfectant solution which has a temperature of 0-3°C. There is also described an ultrasonic apparatus which disrupts or destroys the film of water which io adheres to the skin of the carcass and loosens the skin to allow for maximum contact by the disinfectant present in the solution.

US 5939115 describes a post-evisceration process to reduce the quantity of bacterial contamination of poultry carcass skin in which eviscerated poultry carcasses are immersed for between three and ten seconds in a tank of disinfectant solution (La chlorine mixed with water) heated to a pasteurizing temperature of 45-75°C. The apparatus also comprises an ultrasound apparatus to dislodge bacteria adhered to the skin of the eviscerated carcass.

US 5178890 discloses a method for reducing the level of bacterial contamination in processed poultry in which the poultry carcasses are immersed for two to three minutes in a water/acid solution (e.g. lactic acid at 5cm3 per litre of water) heated to 50°C. The process takes place after de-feathering and before evisceration.

However, Council Regulation (EC) 843/2004 on specific hygiene rules for food of animal origin requires that only potable or clean water is used in the EU for the decontamination of poultry skin during commercial food production processing (unless use of an additional substance has been specifically approved) and therefore the addition of chlorine or lactic acid is not suitable for processing poultry in EU countries. Moreoever, the use of acids and disinfectants increases the cost of the process, not just in terms of the supply of chemicals but also in terms of the health and safety and supply considerations, as well as staff training in handling bulk and potentially harmful chemicals.

Accordingly, it is a non-exclusive object of the invention to provide a method of and apparatus for the decontamination of poultry carcasses which can be used in-line, and preferably at a high rate of throughput, and which effectively reduces the bacterial burden on a carcass. It is a further non-exclusive object of the invention to provide a method and apparatus which does not require sonication or other complex electrical machinery to facilitate the reduction in bacterial burden.

Accordingly, a first aspect of the invention provides a method of decontaminating a poultry carcass, the method comprising after a defeathering stage, but before an eviscerating stage, immersing the carcass in water heated in the range of 60 to 90°C for less than 20 seconds.

A second aspect of the invention provides a poultry processing plant comprising, in-line, a defeathering stage, a decontamination stage and an eviscerating stage, wherein the decontamination stage comprises a tank of water heated to 60 to 90°C and means to immerse a carcass in the water for less than 20 seconds.

It has been surprisingly found that the relatively high temperatures, but relatively low immersion times are beneficial in effectively reducing the bacterial burden on a poultry carcass. The high temperature acts to decrease the bacterial burden whilst the short immersion time ensures that no damage is sustained by the carcass. Advantageously, the short immersion time ensures that the decontamination is able to form part of a conventional in-line processing plant.

Preferably the water is potable water.

The water may be heated to a temperature in the range of 65 or 70°C to 90 or 88°C, for example to a temperature in the range of 76 to 90°C. Preferably, the water is heated from 71, 72, 73, 74, 75, 76, 77, 78, 79°C to one of 87, 86, 85, 84°C. Most preferably, the water is heated from 79 to 83°C.

The immersion time may be less than 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3 seconds, most preferably less than 2.5 seconds. Typically, longer immersion times will be used with lower temperatures.

The apparatus may comprise a tank having an inlet end and an outlet end.

The tank may comprise conveying means, for example conveying means to continuously move carcasses from the inlet or leading end to the outlet or trailing end. Preferably said conveying means may be operable to cause immersion of carcasses in and removal of carcasses from water held within the tank.

In one embodiment said conveying means may comprise a rail section. The rail section preferably having means to receive a hangar from which a carcass is hangable. The conveying means or rail section preferably has a first lead-in portion, a second immersion portion and a third lead-out portion. The lead-out portion is preferably longer than the io lead-in portion. The lead-in portion is preferably shorter than the lead-out portion so that, with a carcass traversing the tank at a constant rate the residence time of the carcass through the lead-out portion will be longer than the residence time in the lead-in portion.

The lead-out portion preferably provides a carcass drip zone within the tank.

In another embodiment, said conveying means may comprise a track, for example a carousel wheel, wherein as a carcass is conveyed over the tank it is dunked or immersed in the water contained within the tank. Thereafter, the carcass may travel over the lead-out portion of the tank, and may drip water into the tank. To minimise the length of the tank it may well be that the immersion zone is towards the inlet or leading end of the tank.

Washer means may be provided within the tank. Said washer means may force or spray water, for example potable water, over the carcass. Preferably washer means are located at or towards the outlet or trailing end. Preferably washer means are located at or within the lead-out portion of the conveying means or rail section. Additionally or alternatively, the or subsequent washer means may be downstream of the tank. The washer means may be arranged to spray water which is below ambient temperature, for example water which is from 2 to 15°C, say 3 to 10°C.

The tank may comprise water heating means. Said water heating means may comprise a steam delivery means. The water heating means may be arranged or may be operable to cause turbulent flow within water held in the tank. In one embodiment the water heating means comprises a sparge pipe, through which steam is delivered or is deliverable to heat the water and, preferably, to cause or induce turbulence within the water held in the tank. The water heating means may comprise primary and secondary heating means. The secondary heating means may comprise an immersion heater. Typically, said secondary heating means is usable for initial heating of the water within the tank, for example during start-up operations.

The steam delivery means is preferably arranged to deliver food grade steam, for s example so-called clean steam' or cpure steam' or other steam which is absent boiler water chemicals and other chemical or physical contaminants and which is dry.

A yet further aspect of the invention provides a decontamination station for poultry processing, the station comprising a tank for holding a body of water, the tank having an io leading end and trailing end and conveying means for conveying poultry from the leading end to the trailing end along, in series, a lead-in portion, an immersion portion to immerse poultry in the water held in the tank for less than 20 seconds and a lead-out portion, wherein, in use, the poultry has a longer residence time in the lead-out portion than the lead-in portion and water heating means capable of heating water within the tank to a is temperature of from 60 to 90°C.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may", "and/o(, "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present.

Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

The invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a schematic flow diagram of a prior art method of processing poultry for food production; Figure 2 is a schematic flow diagram of a method of processing poultry for food production according to an embodiment of the invention; Figure 3 is a side view of a decontamination station according to an embodiment of the invention; Figure 4 is an end view of the decontamination station of Figure 3 showing poultry carcasses within the station; Figure 5 is a graph of data derived from Example 1; and Figure 6 is a plan view of a decontamination station according to a second embodiment of the invention.

Referring now to Figure 1, there is shown a schematic flow diagram of a known method 1 of processing poultry for food production.

A modern, automated poultry processing plant will typically process 8000 to 14000 carcasses an hour (we define such a production rate as "commercial processing" and, in this specification, "commercially processing" should be correspondingly construed). In larger automated plants higher throughputs may be used or parallel lines may be utilised.

In smaller automated plants the throughput will be less. In either case, it will be appreciated that the number of carcasses being processed means that cross-contamination is likely to be of concern even where extremely high standards of monitoring and cleanliness are deployed.

The prior art method 1 includes hanging poultry from their hocks and conveying them through the plant. The method comprises successive stages of stunning 2', bleeding 3', scalding 4', defeathering 5', eviscerating 6', chilling 7' and optionally jointing 8' the poultry.

Within this known process cross-contamination of poultry by campylobacter (and other bacteria) is most likely to occur within one or more of the scalding 4, defeathering 5, and eviscerating 6' stages.

During scalding 4', the carcasses are submerged in heated water for a period of time. The scalding process is provided to soften and loosen the feathers for the subsequent defeathering process. A typical scalding process (known as "semiscalding") will involve submerging a carcass in hot water at a temperature of 50 to 55°C for 90 to 240 seconds.

The scalding process reduces the pulling force required to defeather the carcass. It is possible to increase the temperature of the scalding process to 58 to 60°C with a reduced immersion time, for example 30 to 75 seconds, (so called "subscalding") but this leads to, or at least can lead to, the outer layer of skin of the carcass being broken down which may result in rejection of the carcass at the one or more inspection points which are located at stages along the line (not shown).

As will be appreciated, as the temperature increases the likelihood of superficial or deep damage to the carcass (La cooking) is increased. Any damage to the underlying flesh or discoloration of the carcass will likely lead to rejection of the carcass, which is wasteful and hence sub optimal. Hence, semiscalding is the preferred method of scalding carcasses, especially for broiler chickens.

Defeathering is usually conducted with hydraulically or electrically driven rotating drums provided with plural rubber fingers. Alternatively, the carcass can be rotated against stationary (or contra-rotating) rubber fingers. As the drums and carcass rotate relative to one another the rubber fingers frictionally engage the feathers and remove them from the carcass. This process is best undertaken close to the scalding zone so that the temperature of the carcass remains as close to the scalding temperature as possible.

After defeathering the pinfeathers that survive conventional defeathering are removed by a pinning' operation, conventionally undertaken by hand or by dipping in a hot wax (55°C) bath. Typically the carcass receives a second dipping in the wax and the wax is solidified by immersion in cold water. Once the wax has hardened it can be peeled off to remove the pinfeathers. The hot wax method is more usually deployed for ducks and geese rather than for broiler chickens where a manual method is preferred.

During the evisceration stage a venter drills out the cloaca (venting) which allows a clamp to enter the carcass' cavity and grip the visceral package and carefully withdraw it from the cavity. The belly skin of the carcass may also be slit. Upstream or downstream of the eviscerator the neck will be cut, removed and the remaining neck skin trimmed. The edible parts of the viscera (for example the heart, liver, spleen, kidneys, gizzard) will be separated from the inedible parts.

The carcass is then thoroughly washed, both externally and internally using high pressure nozzles and the carcass is then passed to a chilling zone to slow down harmful microbial growth.

Clearly, the removal of the viscera from the carcass' cavity may well be a important stage in the control of bacterial infestation and great care is deployed to ensure that evisceration is carried out so as to minimise contamination, i.e. that the GI tract is not breached, thereby directly exposing the carcass to faecal matter.

That said, it has also been noted (R/sk AnaL, 27(4), pp 831-844 (2007)) that the scalding operation can lead to cross contamination both within flocks and between flocks and that the contamination can be exacerbated during and after defeathering because the action io of the defeathering apparatus on the carcass can lead to the generation of airborne bacteria (typically in aerosols) and/or cross contamination by contact.

Referring now to Figure 2, there is shown, according to one embodiment of the invention, a schematic flow diagram of an improved method 10 of processing poultry for food production, where like references (absent the prime ()) depict like stages which will not be described further herein. The improved method 10 additionally involves a decontamination stage 11 which occurs subsequent to defeathering 5 and prior to eviscerating 6.

Surprisingly, we have found that immersing the defeathered carcass into hot, preferably potable, water for a very short period of time leads to substantial reductions in bacterial infection. We have even more surprisingly found that conducting the decontamination stage pre-evisceration ensures that the carcass maintains a low bacterial loading throughout the downstream process stages.

Moreover, short immersion times have been found not to damage the carcass, leading to zero rejection rates as a consequence of the treatment and no interruption to throughput of carcasses, especially when commercially processing carcasses. The decontamination stage using water (most preferably potable water) ensures low capital and running costs, and little to no further training or supervision of on-site personnel. The use of potable water is further advantageous because there are no material supply or regulatory issues.

Referring now to Figures 3 and 4, there is shown, according to one embodiment of the invention, a decontamination station 200, in which the decontamination stage 11 described above, and shown in Figure 2, occurs.

The decontamination station 200 includes a tank 20 having an inlet end 21 and an outlet end 22 disposed along a longitudinal axis, a supporting frame 30 intermediate the inlet and outlet ends 21, 22, an immersion tank 40, a conveying system 50, a cooling system 60 and a water heating system 70, The supporting frame 30 includes vertical elongate members 31 attached adjacent their upper ends to longitudinally extending horizontal support members 32, and by latitudinally extending horizontal support members 33.

The immersion tank 40, which is composed of stainless steel, is substantially rectangular in plan with a base 41 and side walls 42 and inlet and outlet end walls 43a, 43b, which extend perpendicularly upwards with respect to the base 41. The immersion tank 40 is preferably thermally insulated on its outer surface by an insulating material (e.g. high is density fibreglass). Additionally or alternatively the immersion tank 40 may be composed of a thermally insulating material. The immersion tank 40 is located substantially within the frame 30 such that inner surfaces of the vertical elongate members 31 are configured to engage with and affix to the outer surface 44 of the side walls 42 of the immersion tank 40, so that the base 41 of the immersion tank 40 does not engage with the ground. In this way the immersion tank 40 is suspended by the frame 30 at a height above the ground and therefore ambient air surrounds the majority of the outer surfaces of the base 41, sides 42 and ends 43a, 43b of the immersion tank 40, thus providing an additional layer of thermal insulation. The immersion tank 40 may be affixed by any suitable means to the vertical elongate members 31, where such means may, for example, include adhesive and/or bracket supports (not shown).

The immersion tank 40 has an internal depth H an internal length L and an internal width W. Those skilled in the art will appreciate that the internal depth H of the tank may be any dimension suited to fully immersing poultry in a fluid contained within the tank, the internal length L of the tank may be any dimension suited to the required processing time of the poultry, whilst the internal width W may be any dimension suited to the size of the poultry.

The internal depth H may, for example, be 1000mm, the internal length L may, for example, be 5000mm, and the internal width W may, for example, be 700mm.

The conveying system 50 includes a conveyor rail 51 operatively connected to a driving means (not shown) and a control console (not shown). The conveyor rail 51 is affixed to and/or suspended from the horizontal support members 32, 33 of the frame 30, whereby the conveyor rail 51 extends longitudinally through the decontamination station 200, s equidistant from the vertical elongate members 31 of the frame 30. The conveying system further includes a conveyor attachment 52 attached at one end to the conveyor rail 51 and at its free end to a hook 53 for engaging the feet of poultry. Additionally or alternatively, the conveyor rail 51 may be affixed to and/or suspended from a master frame (not shown) which operatively connects the decontamination station 200 with the defeathering station (not shown) and/or the evisceration station (not shown).

As shown in side in Figure 3 the conveyor rail 51 is adjacent to the horizontal support members 32, 33 of the frame 30 at the inlet end 21 of the station 200 and at the outlet end 22 of the station 200. Intermediate the inlet and outlet ends 21, 22 of the station 20 the is conveyor rail 71 includes inlet, submersion and outlet portions 54, 55, 56. In the inlet portion 54 the conveyor rail 51 descends from the frame 30 towards the immersion tank 40. In the submersion portion 55 the conveyor rail 71 maintains a constant height relative to the immersion tank 40 and in the outlet portion 56 the conveyor rail 51 ascends back towards the frame 30.

The height of the conveyor rail 51 relative to the tank 40 in the submersion portion 55 is selected to ensure that poultry suspended from the conveyor rail 51 will be entirely submerged within water contained in the tank 40, and is dependent on both the depth of water within the tank 40 and the length of the hook 53.

The length of the submersion portion 55 of the conveyor rail 51 is selected in consideration of the required duration of poultry carcass submersion and the rate at which carcasses are conveyed through the decontamination station 200. For example, for a submersion duration of one second, at a rate of lm/s, the length of the submersion portion 55 of the conveyor rail 51 is 1 m. Additionally or alternatively, the line speed of the conveyor rail 51 may be operatively controlled in order to increase or decrease the duration of submersion of carcasses under the water.

The outlet portion 56 further includes, sequentially from the submersion portion 55 to the outlet end 22 of the station 200, a withdrawal zone 57, a drip zone 58 and a cooling zone 59. In the withdrawal zone 57 a conveyed carcass is withdrawn from the water in the immersion tank 40. In the drip zone 58 water and contaminate drips from a conveyed carcass down into the immersion tank 40. In the cooling zone 59 a conveyed carcass is cooled and cleaned by the cooling system 60.

The length of the outlet portion 56 is greater than the length of the inlet portion 54, so that a poultry carcass traversing the station 200 at a constant speed will have a higher residence time in the outlet portion 56 than in the inlet portion 54. By minimizing the residence time of a carcass in the inlet portion 54 the total residence time of a carcass io within the station 200 is also minimized. Therefore, advantageously, the rate at which carcasses may be decontaminated within the station 200 may be maximised.

The cooling system 60, located in the cooling zone 59 at the outlet end 22 of the decontamination station 200, includes a header tank 61 attached to the outlet end wall 43b of the immersion tank 40. A vertical cold water pipe 62, having a connection and free end, is fluidly connected at its connection end to the header tank 61. The cold water pipe 62 is fluidly connected, intermediate its ends, to an intermediate pipe system 63 including narrow bore horizontal pipes 64 extending over the outlet end of the immersion tank 40, with narrow bore vertical pipes 65 extending from their free ends. The vertical pipes 65 are arranged in opposed pairs inboard of the vertical elongate members 31 of the frame and spaced relative to one another by a latitudinal distance similar to the inner width W of the immersion tank 40. A plurality of spray nozzles 66, evenly spaced relative to one another, are located towards the free end of the vertical pipes 65, and on the inner surfaces of the pipes 65 relative to a central axis of the station 200. The vertical pipe pairs 65 are arranged at suitable longitudinal intervals along the cooling zone 59 of the decontamination station 200. Additionally the header tank 61 may be fluidly connected to the immersion tank 40 via a top-up valve (not shown) so that water from the header tank 61 may be used to replenish water lost from the immersion tank 40 due to boiling and/or surface contact with poultry. The water dripping from the carcass and/or waste water from the spray may also automatically flow to a drain should the water level in the tank be at or above a designated level.

The tank 20 is provided with a water heating system 70 including a pressurised steam supply apparatus 71, a supply pipe 72 and an inlet valve 73 and is configured to heat water contained within the immersion tank 40. The steam supply apparatus 71, preferably located above the frame 30, controls pressurised steam supplied by a boiler (not shown) to the inlet end 72a of the supply pipe 72. The outlet end 72b of the supply pipe 72 is connected to the inlet valve 73 which is located adjacent to the outer surface of the inlet end wall 43a of the immersion tank 40 and is fluidly connected to an inlet pipe 74 running through a sealed inlet aperture 75 through the inlet end wall 43a of the immersion tank 40, adjacent to the base 41 of the immersion tank 40. The free end of the inlet pipe 75 is fluidly connected to a sparge pipe 76 which extends adjacent to the inner side of the base 41 of the immersion tank 40 along a major portion of the inner length L of the immersion tank 40. The sparge pipe 76 includes an elongate tube 77 having a plurality of small apertures (not shown) located in its upper surface. The steam introduced into the tank to maintain the temperature may be sufficient to ensure that evaporative losses are balanced.

In use the immersion tank 40 is filled with potable water. The steam supply apparatus 71 is operated by the controller to supply steam from the boiler to the supply pipe 72. The inlet valve 73, opens to allow the pressurised steam to flow through the inlet aperture 75 and into the sparge pipe 76. Pressurised steam exits the sparge pipe 76 through the plurality of small apertures, heating the surrounding water in the immersion tank 40. The inlet valve 73 may be self-controlled, for example, via a thermal feedback mechanism monitoring the temperature of the water in the immersion tank 40. Alternatively, the inlet valve 73 may be operative controlled by the controller (not shown).

Additionally or alternatively, the start-up heating process may use a secondary heat means, for example one or more immersion heaters or secondary steam systems.

Subsequently or consecutively cold water is pumped via a pump (not shown) from the header tank 61 through the cold water pipe 62 and into the intermediate pipe system 63.

The cold water passes through the horizontal pipes 64 and into the vertical pipes 65 and subsequently sprays from the spray nozzles 66 on the vertical pipes 65 before being collected in the immersion tank 40.

A thermal sensor (not shown) located in and/or adjacent to the water contained in the immersion tank 40 is operatively connected to the controller, such that the controller receives thermal information from the thermal sensor corresponding to a temperature of the water in the immersion tank 40. The controller compares received thermal information against a trigger value, and/or against a trigger range of values, where the trigger value corresponds to a required temperature of the water, and the trigger range of values corresponds to a required range of temperatures of the water. The trigger value and/or trigger range of values may be pre-prograrred into the controller and/or may be manually s set by an operator. If the controller determines that the received thermal information corresponds to the trigger value and/or range of trigger values the conveying system 50 is operated by the controller to move poultry carcasses (suspended by their ankles via hooks 53 from the control rail 51) from the defeathering station (not shown) and through the inlet 21 of the decontamination station 200.

Poultry carcasses conveyed within the inlet portion 54 of the conveyor rail 51 descend into, and are immersed within, the water within the immersion tank 40. The poultry carcasses are conveyed, entirely submerged in the water of the immersion tank 40, within the submersion portion 55 of the conveyor rail 51. In the withdrawal zone 57 of the is conveyor rail 51 the poultry carcasses are withdrawn from the water to a position above the water in the immersion tank 40.

Subsequent to exiting the withdrawal zone 57 of the conveyor rail 51, the poultry carcasses are conveyed into the drip zone 58 where water and detritus (for example fecael matter) drips into the immersion tank 40. The carcasses are subsequently conveyed into the cooling zone 59 of the station 200, where cold water from the spray nozzles 66 is incident upon the poultry carcasses. The cold water spray cools the poultry carcasses prior to their exit from the outlet end 22 of the decontamination station 200.

Additionally or alternatively, the cold water spray may remove additional contaminant from the skins of the carcasses, wherein the contaminant may, for example, constitute faecal or other detritus accumulated on the surface of the water in the immersion tank 40.

The conveyor rail 51 may move the poultry carcasses continuously through the decontamination station 200 at a constant speed. Alternatively, the conveyor rail 51 may move the poultry carcasses at a variable speed. Additionally or alternatively the conveyor rail 51 may pause the movement of the poultry carcasses at one or more times within the station 200. For example, the pausing may occur when a poultry carcass is located within the submersion portion 55 of the conveyor rail 51 and/or when a poultry carcass is located within the cooling zone 59 of the station 200.

Without wishing to be bound by any theory it is believed that the entirely submerged movement of the poultry carcasses within the heated water of the immersion tank 40 provides enhanced decontamination of microbial bacterial through two mechanisms.

Firstly, by exposing the microbial bacteria to a relatively high temperature a significant proportion of the bacteria are killed. Secondly, by moving the entirely submerged carcasses though the water there is abrasion between the water and the skin of the poultry resulting in the dislodging of contaminated matter from the poultry carcasses. The pressurised steam within the water may generate vortices and/or other forms of turbulent flow in the immersion tank 40, thereby enhancing the abrading effect of the water against io the skin of the poultry and hence increasing the percentage of contaminated matter dislodged from the poultry carcasses.

In order to demonstrate the efficacy of the decontamination stage in the processing of poultry a set of Examples were carried out, as follows:

Example 1

A series of defeathered carcasses were sampled and tested for bacteria. Each carcass was immersed in hot potable water heated to 82°C for a period of 1.5s. The carcasses were sprayed with cold potable water and samples were taken for subsequent testing.

The results are shown in Figure 5 and illustrated in tabular form below, as follows: Species Abbreviation Average Kill (%) Total Aerobic Colony Count TACC 91.8 Entorobacteriaceae. Presumptive EBP 93.3 Coagulase Positive Staphylococci CPS 59.9 Presumptive Pseudomonas Species PPS 93.0 E. Coli EC 97.9 Campylobacter Species CS 91.2 Table 1. Results from trial of decontamination The results clearly demonstrate the efficacy of the technique, with all but one of the bacterial species showing a kill rate of above 90%.

In terms of CPS the low kill rate is due to a small sample size. Of all the carcasses tested, only 20% tested positive for CPS pre-treatment. This means that the sample size was small and the error in the sampling measurement was commensurately high.

Clearly, the decontamination stage and process according to the invention is capable of significantly reducing the bacterial loading on a carcass.

Example 2

io In order to test the efficacy of the decontamination stage and process the neck skin of a first set of carcasses (control set) was sampled at two points, 1) post defeathering and 2) post evisceration to determine the bacterial loading at two points of a prior art processing line (La as per Figure 1).

The neck skin of a second set of carcasses (experimental set) was sampled at two points, 1) post defeathering and 2) post evisceration to determine the bacterial loading at two points of a processing line according to the invention (La as per Figure 2). The decontamination stage comprised immersing the carcasses in hot potable water (81°C) for a short time period (2 seconds).

The sample size of the control set and experimental set were identical.

The results are indicated below, as follows: Variable Average Kill (%) Sig. Diff (P<0.05) CS (post defeathering) 99.9 Yes (<0.01) CS (post evisceration) 99.5 Yes (<0.01) Table 2. Results of decontamination as compared to non-decontamination The results show that campylobacter species (CS) were significantly reduced by exposure to the decontamination stage as compared to non-exposure to the decontamination stage (relative 99.9% average kill).

The results further demonstrate that post evisceration the relative reduction in CS species by carcasses exposed to the decontamination stage, as compared to those not exposed to the decontamination stage was maintained (relative 99.5% kill rate).

This clearly shows that the decontamination stage was capable of effectively reducing campylobacter contamination as compared to non-decontaminated carcasses through the evisceration stage.

Example 3

In order to test the efficacy of the decontamination stage and process the neck skin of a first set of carcasses (control set) was sampled at two points, 1) post defeathering and 2) io post chill to determine the bacterial loading at two points of a prior art processing line (Le.

as per Figure 1).

The neck skin of a second set of carcasses (experimental set) was sampled at two points, 1) post defeathering and 2) post chill to determine the bacterial loading at two points of a processing line according to the invention (La as per Figure 2). The decontamination stage comprised immersing the carcasses in hot potable water (82°C) for a short time period (ito 1.5 seconds).

The sample size of the control set and experimental set were identical.

The results are indicated below, as follows: Variable Average Kill (%) Sig. Diff (PcO.05) CS (post defeathering) 99.9 Yes (<0.01) CS (post chilling) 99.7 Yes (<0.01) Table 3. Results of decontamination as compared to non-decontamination The results show that campylobacter species (CS) were significantly reduced by exposure to the decontamination stage as compared to non-exposure to the decontamination stage (relative 99.9% average kill).

The results further demonstrate that post chilling the relative reduction in CS species by carcasses exposed to the decontamination stage, as compared to those not exposed to the decontamination stage was maintained (relative 99.7% kill rate).

This clearly shows that the decontamination stage was capable of effectively reducing campylobacter contamination as compared to non-decontaminated carcasses through the evisceration stage and into the chill stage.

This is a very important result because it demonstrates that decontamination intervention post defeathering, according to the invention, is capable of ensuring a low bacterial loading throughout the subsequent processing of the carcass and into the chill zone (where bacterial activity will be down regulated due to the effect of the low temperature to which the carcasses are exposed).

The experiments demonstrate that immersion in hot water, say from 60 to 90°C for a period of less than 20 seconds provides an effective way of combating bacterial contamination in poultry processing, without the need for expensive sonication (or other) equipment or the use of dangerous or expensive chemicals.

The method resulted in zero rejection rate of carcasses through exposure to the high temperature. This is important because without the protective layer of feathers there is a risk that exposure of the carcass to such high temperatures might damage the carcass.

Our experiments found no such damage due to the short immersion times.

In both Examples 2 and 3 the neck skin was sampled. It is believed that the neck skin of poultry is the most difficult skin to decontaminate and most prone to bacterial loading.

Hence, our invention successfully demonstrates efficacy against the paradigm case of bacterial contamination.

Example 4

We carried out a series of test runs using the apparatus of Figures 3 and 4, wherein the water in the tank was heated to, and maintained at, 80°C by steam and the immersion time was 1.25 seconds (immersion zone 1 m long, line speed 0.8 mIs).

We found that bacterial loading was as low or lower than in previous experiments.

Thus, we believe that the use of a turbulent pool of heated (preferably potable) water has the capacity to further increase the effectiveness of the decontamination stage because it disrupts the lamina of water proximate the carcass and further helps to remove adherent bacteria and other matter.

The decontamination stage need not be used on an in-line, automated operation. It can also be deployed in a semi-automated or manual poultry processing operation.

The method and apparatus is particularly useful with chickens, for example broiler chickens, but may also be deployed with other poultry (ducks, geese, turkeys and so on).

io The conveying means need not be as shown in Figures 3 and 4. Reference is made to Figure 6, which shows a decontamination zone 11 comprising a tank 40' and a conveyor 50'. The conveyor 50 comprises a plurality of hooks (not shown) on a carousel wheel 51'.

Carcasses C may be suspended from the hooks in the traditional manner.

The carousel wheel 51' is arranged to rotate in the direction of arrow A, thereby moving carcasses C from a loading point 52' to an unloading point 53' and over the tank 40'.

As before, the tank 40' has a leading end 41' and a trailing end 42' and is (nominally) separated into a lead-in portion I', an immersion or submersion portion II' and a lead-out portion Ill'.

There may be provided one or more carcass washers 60' in the lead out portion Ill'.

As a carcass C enters the submersion portion II' it is automatically dunked into the hot potable water contained in the tank 40' for a time period according to the invention, e.g. less than 20 seconds. The water may be heated to 70 to 83°C and the submersion time may be less than 3 seconds, for example 82°C for 1 to 2 seconds. Submerging the carcass C by plunging or dunking is likely to disrupt any surface lamina of water on the skin of the carcass.

Although the conveyor 50 has been described as comprising a carousel wheel, it need not. Carousel wheels are convenient because they efficiently use space, for example, the loading point 52' and unloading point 53' need not be diametrically opposed (as shown) but may be at any other angle. Alternatively, the conveyor may comprise a simple track rather than a carousel wheel.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, 5. the carcasses could take a tortuous path through the decontamination stage, which may further increase turbulence; * a wash zone may be provided before the decontamination stage, spraying the carcass with water, preferably potable water; * the tank can be any suitable shape; * various conveying means may be deployed; * the water may be heated by any suitable means; * water agitators may be provided within the tank; * ultrasonic agitators may be provided within the tank.

is It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

Claims (21)

1. CLAIMS1. A method of decontaminating a poultry carcass, the method comprising after a defeathering stage, but before an eviscerating stage, immersing the carcass in water heated in the range of 60 to 9000 for less than 20 seconds.
2. 2. A method of commercially processing poultry, the method comprising continuously passing poultry carcasses along a processing line which complises a scalding stage, a defeathering stage and a evisceration stage and after the defeathering io stage but before the eviscerating stage, immersing a carcass in water heated in the range of 60 to 90°C for less than 20 seconds.
3. 3. A method according to Claim 1 or 2, comprising immersing the carcass in the water for less than 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3 seconds, most preferably less than 2.5 seconds.
4. 4. A method according to any of Claims 1, 2 or 3, comprising immersing the carcass in water heated to 65 or 70°C to 90 or 88°C.
5. 5. A method according to any preceding Claim, comprising immersing the carcass in water heated to 75 to 85°C for a period of less than 2.5 seconds.
6. 6. A method according to any proceeding Claim, comprising immersing the carcass in water heated from 79 to 83°C for a period of less than 2 seconds, preferably immersing the carcass in water heated from 80 to 82°C for a period of 2 seconds or less, e.g. 1.5 seconds or less.
7. 7. A method according to any preceding Claim, comprising agitating the water in which the carcass is immersed.
8. 8. A poultry processing plant comprising, in-line, a defeathering stage, a decontamination stage and an eviscerating stage, wherein the decontamination stage comprises a tank of water heated to 60 to 90°C and means to immerse a carcass in the water for less than 20 seconds.
9. 9. A processing plant according to Claim 8, wherein the decontamination stage comprises water heating means arranged to heat the water to 65 or 70°C to 90 or 88°C, and preferablytoheatthewatertofrom 71, 72, 73, 74, 75, 76, 77, 78, 79°C to one of 87, 86, 85, 84°C, most preferably, to heat the water to 79 to 83°C.
10. 10. A processing plant according to Claim 8 or 9, wherein the tank has a leading end and a trailing end.
11. l1.A processing plant according to any of Claims 8, 9 or 10, wherein the decontamination stage comprises conveying means to continuously move carcasses from the or a leading end to the or a trailing end of the tank.
12. 12. A processing plant according to Claim 11, wherein said conveying means is operable to cause immersion of carcasses in and removal of carcasses from water held within the tank.
13. 13. A processing plant according to Claim 11 or 12, wherein said conveying means is operable to cause immersion of carcasses in the water for a period of less than 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3 seconds, most preferably less than 2.5 seconds.
14. 14.A processing plant according to any of Claims 11, 12, 13, wherein the conveying means includes a lead-in portion, an immersion portion and a lead-out portion.
15. 15. A processing plant according to Claim 14, wherein the lead-out portion is longer than the lead-in portion.
16. 16. A processing plant according to Claim 15, wherein the lead out portion comprises a carcass drip zone.
17. 17. A processing plant according to Claim 14 or 15, wherein the lead-out portion comprises a carcass wash zone.
18. 18. A processing plant according to any of Claims 8 to 17, wherein a downstream portion of the tank comprises a carcass washer.
19. 19. A processing plant according to Claim 18, wherein the carcass washer comprises means to spray the carcass with water, preferably potable water, and most preferably potable water which is cooled to below 15°C.
20. 20. A processing plant according to any of Claims 8 to 19, wherein the tank comprises water agitation means.
21. 21. A decontamination station for poultry processing, the station comprising a tank for holding a body of water, the tank having a leading end and outlet trailing end and conveying means for conveying poultry from the leading end to the trailing end along, in series, a lead-in portion, an immersion portion to immerse poultry in the is water held in the tank for less than 20 seconds and a lead-out portion, wherein, in use, the poultry has a longer residence time in the lead out portion than the lead in portion and water heating means capable of heating water within the tank to a temperature of from 60 to 90°C.