IE84453B1 - A cattle slaughtering and meat tenderising process - Google Patents

Description

A cattle slaughtering and meat tenderising process Introduction The present invention relates to a cattle slaughtering and meat tenderising and conditioning process.

As has long been known, one of the factors which influences the tenderness of meat and hence its organoleptic properties, is the degree of stretch of the muscle of the meat. The muscle structure or sarcomere consists of a length of muscle filament which contracts on the muscle being tightened and expands on the muscle being relaxed. It is known that the whole slaughtering process, indeed the simple transfer of an animal from its own home environment to another, causes stress, which stress causes the animal muscles to tighten and thus the sarcomere length to be reduced. Animals which are inspected immediately after stunning have been known to have contracted muscles and indeed this is generally the case. Subsequently, when the animal is slaughtered, rigor mortis sets in and the carcass has all these tightly knit and hard muscles which are contracted. It has been proposed, such as disclosed in US Patent Specification No. 2001/0034201 (Bell et al), to tenderise meat by stretching prior to the onset of rigor mortis. This is carried out by separating the vertebrae and allowing the carcase to hang and stretch under gravity. Various methods have been proposed such as electrical stimulation , to assist in relaxing the muscles of the slaughtered animal.

It is known to process carcasses, after slaughtering, by retaining the carcasses in a cooled environment at temperatures of the order of 4 to 6°C with a relatively high humidity of the order of 98%, such as, for example, disclosed in UK Patent Specification No. 2356792 (Agri—Dev Limited). In this patent specification, there is described a system in which the carcass is maintained at a relatively low temperature initially. A somewhat similar arrangement for cattle, rather than pigs, is described in US Patent Specification No. 2315285 (Dennington).

The present invention is also directed towards this and also directed towards providing a post mortem handling process of the carcass that will facilitate the stretching of the muscles.

Statements of Invention According to the invention, there is provided a cattle slaughtering and meat tenderising and conditioning process comprising carrying out the steps of:- receiving the cattle in a separate Iairage station; carrying out an ante-mortem veterinary examination for pathogens and indicator organisms; sending the cattie to a slaughtering station; stunning the animal; suspending the animal by one hind leg on an electrically earthed overhead transfer rail along which the carcass is sent to various stations where the further steps are carried out; ensuring the animal is stunned and relaxed and then slaughtering the animal by bleeding it within sixty seconds of stunning; collecting the blood; attaching the other hind leg to the rail; transferring the hide to a hide removing station; removing the hide; removing the head; removing the intestines in evisceration stages, first removing red offal fit for human consumption and then green offal, unfit for human consumption; brisket sawing the carcass into two carcass sides; within a preset time from carrying out the step of stunning the animal and after brisket sawing, dropping the head of the flank of the carcase side away from the knuckle hip suspending the carcase side on the rail; stretching the carcase side by drawing the shank to an angle of between 160° and 145° from the vertical; transferring the carcase side to a chill chamber and maintaining the carcass for at least 8 hours at a temperature greater than 10°C and at a relative humidity in excess of 90% in a first conditioning stage; reducing the temperature to between 4 and 6°C and at a relative humidity greater than 85% within 2 to 5 hours thereafter in a second conditioning stage; and in a third and final conditioning stage, reducing the temperature to between 0°C and 2°C at a relative humidity greater than 75% for a further four to eight days after completion of the second conditioning stage.

This greatly increases the tenderness of the resultant meat as the stretching of the muscles is achieved at a relatively high temperature prior to rigor mortis setting in..

Preferably, the carcass sides are hung in the chill room with a space between each carcass side and air is circulated around the carcass side at a speed of between 0.2 and .5 m/sec.

Preferably, the shank is drawn down to an angle of approximately 150° by attaching a connector between the shank and between the third and fourth ribs of the sternum. After the first conditioning stage, this stretching may be removed.

Further, the process includes, on suspending the side of beef on the rail, the upper part of the hindquarter flank is detached from the topside and the rump cups to hang vertically.

In one embodiment of the invention, the second conditioning stage is carried out for approximately 3 hours.

Ideally, the shank is maintained in the drawn down state until after the end of the first conditioning stage when rigor mortis has set in.

In the process according to the invention, the humidity in the first, second and third stages is maintained at greater than 95%, 90% and 80% respectively and air is circulated round the carcass sides at speeds between 0.3 and 1.0 m/sec. petaile(_i_Description of t_he Invention The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a plan layout of a typical slaughterhouse according to the present invention; Fig. 2 is an enlarged view of portion of Fig. 1 as shown by the interrupted lines in Fig. 1, Fig. 3 is a front view of half of a carcass side suspended on a rail.

Before describing the process according to the invention, in detail, for ease of understanding, each of the main operations and where it takes place, namely, the stations have been identified by the circled numerals 1 through to 22 which are laid out in Table 1.

Table 1 Listing of Operations and Stations Station No.

-J>~CA)l\)—l 12 13 14 16 17 18 19 21 22 Lairage intake and fill chute Stun, shackle, stick and stimulate Front feet, nose bits and wizzen First and second leg Flanking Roses — clip back hides; remove tags and attach to animal, remove horns Hide puller and controls Hide puller and bung Front stumps off, tongues out, heads off and stimulate Cut brisket, eviscerate and pluck Carcass saw and spinal cord removal Inspection Spare station Hind—quarter trim Fore-quarter trim Scales Clean and final trim Final inspection Hip hang Feed chills Red Offal trim Green offal trim and divert Most of the apparatus used in accordance with the present invention is conventional except for the stimulation apparatus which is in turn a conventional DC generator. It is easier to describe the present invention by way of describing its operation, rather than attempting to describe the apparatus and then to describe its operation. The slaughterhouse is essentially a conventional slaughterhouse with overhead transfer rail. Generally, all the apparatus used is essentially conventional. The stations listed above described the operations.

Accordingly, as mentioned above, it is easier to describe any different pieces of apparatus as the process is described. In lairage, at intake, the animals are delivered through a cattle race 30 after all the necessary checks on passports, hygiene and animal welfare have been made. All anti—morlant veterinary examinations for pathogens and indicator organisms are carried out prior to entry into the cattle race 30.

Then the animal is delivered through the cattle race 30 to a stun box 31 where the cattle is stunned in conventional manner in station 2. Further, in station 2, one of the anima|’s legs is shackled and the animal is hung on a suitable rail when the animal, which is now stunned and relaxed, is bled which must begin within 60 seconds of stunning. The blood from the animal is then allowed drain into a bloodbath 32 from which it is removed in due course. Then the other hind leg of the animal is connected to the rail, as illustrated in Fig. 2. The rail which is identified by the reference numeral 41 is earthed. The animal is identified by the reference numeral 35 and its hind legs by the reference numeral 38.

Electrical stimulation can be carried out in accordance with our co~pending patent application filed on even date hereof. This operation may be carried out within twenty minutes of stunning. Then, in station 3, the front feet, nose bits and wizzen are removed and in station 4, portion of the first and second legs, namely, a strip of skin, is removed approximately half an inch wide. In station 5, flanking is carried out where portion of the hide is cut back from the carcass. Then, in station 6, further preparation of the carcass takes place such as horn cropping, etc.

In stations 7 and 8, hide pulling is carried out in conventional manner. Then, in station 9, head removal, including removal of tongues, etc. is carried out. In station 10, evisceration takes place with red offal removal. This is a very critical operation. In station 11, the carcass is split by a saw and the spinal cord is removed. There are now essentially two sides. Station 12 is an inspection station, while station 13 is shown as a spare station. Then, in stations 14 and 15, the hind and fore quarters are trimmed and in station 16, the carcass is weighed. in station 17, there is clean and final trim, while in station 18, there is a final inspection. In station 19, the carcass is now changed from its previous suspension so that a meat hook is lodged in the lip of the uschium bone.

Since the carcass is no longer suspended from the hind leg, the hind leg will drop downwards at an angle of between 60 to 90° from the vertical. By hanging in this way, the weight of the carcass acts to stretch the topside, silverside, rump, striploin and fore limb muscles so that a greater stretch is achieved. This stretching of the muscles will increase the sarcomere length and the now stretched muscle yields meat which is softer and more susceptible to shearing and hence more tender.

The stretching effect can be further enhanced by detaching the upper part of the hind quarter flank from the topside and top rump cups as this allows the detached portion to hang vertically downwards.

Referring to Fig. 3, a carcass and strictly speaking, a side of beef or a carcass side, identified by the reference numerals 35, is suspended at 36 by the uschium bone on a transfer rail 41. The hind leg 38 is then attached by a suitable chain or rope 39 which is then attached by a further hook 40 between the third and fourth ribs of the brisket (sternum). The rope 39 is used to pull the shank 38 at an angle of 150° from the vertical. This angle can vary from between 145° to 160°.

After the carcass has been stretched by the use of the chain or rope 39, the carcass side 35 is placed into the chill room which has been preheated to greater than 10°C.

The chill room is set up at approximately 10°C with a relative humidity exceeding 90%.

The stretched carcass is kept in this pre-heated environment for at least eight hours, after which rigor mortis will have set in. The rope 39 may then be removed or alternatively it may be left on the carcass. This provides a first conditioning stage as it allows rigor mortis to gradually set in with the muscles hyper-stretched. Then, in a second conditioning stage, the temperature in the chill room is reduced to approximately 5°C and a relative humidity of the order of at least 85%. This takes place approximately three hours from the onset of stage 2. This final stage will then carry on for a period of up to 16 or 20 hours. Finally, the temperature is further reduced to approximately 1°C with a relative humidity exceeding 75% for the duration.

This can be anytime from between the end of the second stage up to the fifth, sixth or seventh day post slaughter. Then, the carcass is removed for deboning.

During the three stages of conditioning, the carcasses are suspended so as not to touch each other and the air speed around the carcasses is generally controlled within 0.3 to 1.0 mm per second.

In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

The invention is not limited to the embodiment hereinbefore described, but may be varied in both construction and detail within the scope of the appended claims.

Claims (4)

1.CLAIMS 1. A cattle slaughtering and meat tenderising and conditioning process comprising carrying out the steps of:— 35 receiving the cattle in a separate lairage station; carrying out an ante-mortem veterinary examination for pathogens and indicator organisms; sending the cattle to a slaughtering station; stunning the animal; suspending the animal by one hind leg on an electrically earthed overhead transfer rail along which the carcass is sent to various stations where the further steps are carried out; ensuring the animal is stunned and relaxed and then slaughtering the animal by bleeding it within sixty seconds of stunning; collecting the blood; attaching the other hind leg to the rail; transferring the hide to a hide removing station; removing the hide; removing the head; removing the intestines in evisceration stages, first removing red offal fit for human consumption and then green offal, unfit for human consumption; brisket sawing the carcass into two carcass sides; 35 within a preset time from carrying out the step of stunning the animal and after brisket sawing, dropping the head of the flank of the carcase side away from the knuckle hip suspending the carcase side on the rail; stretching the carcase side by drawing the shank to an angle of between 160° and 145° from the vertical; transferring the carcase side to a chill chamber and maintaining the carcass for at least 8 hours at a temperature greater than 10°C and at a relative humidity in excess of 90% in a first conditioning stage; reducing the temperature to between 4 and 6°C and at a relative humidity greater than 85% within 2 to 5 hours thereafter in a second conditioning stage; and in a third and final conditioning stage, reducing the temperature to between 0°C and 2°C at a relative humidity greater than 75% for a further four to eight days after completion of the second conditioning stage.

2. A process as claimed in claim 1, in which:- the carcass sides are hung in the chill room with a space between each carcass side; and air is circulated around the carcass side at a speed of between 0.2 and 1.5 m/sec.

3. A process as claimed in claim 1 or 2, in which the shank is drawn down to an angle of approximately 150° by attaching a connector between the shank and between the third and fourth ribs of the sternum.

4. A process as claimed in claim 3, in which, after the first conditioning stage, the stretching is removed. 10. -11. A process as claimed in any preceding claim, in which, on suspending the side of beef on the rail, the upper part of the hindquarter flank is detached from the topside and the rump cups to hang vertically. A process as claimed in any preceding claim, in which the second conditioning stage is carried out within 3 hours. A process as claimed in any preceding claim, in which the shank is maintained in the drawn down state until after the end of the first conditioning stage when rigor mortis has set in. A process as claimed in any preceding claim, in which the humidity in the first, second and third stages is maintained at greater than 95%, 90% and 80% respectively and air is circulated round the carcass sides at speeds between 0.3 and 1.0 m/sec. A process substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. Meat slaughtered, tenderised and conditioned in accordance with the process as claimed in any preceding claim.