Beef Carcasses

With beef carcass sides, a typical process involves the progressive removal of portions from the hanging side, with each portion being passed to a separate collection or processing line which involves one or more conveyors and often band, circular or reciprocating saws, and powered knives.

From: HACCP in the Meat Industry , 2000

CARCASS CHILLING AND BONING

H.W. Ockerman , L. Basu , in Encyclopedia of Meat Sciences, 2004

Beef

Beef carcass chilling time can be decreased by an increase in air velocity and decrease in temperature. Recommendations are often that the air velocity should be less than 1 m s−1 and the relative humidity should be greater than 80%. Besides the avoidance of cold shortening, ageing is the main factor influencing beef tenderness. Some reports suggest that beef should be at a high temperature for as short a time as possible, and muscles should enter rigor at 10–15 °C for tenderness to be optimized.

Delayed chilling (tenderay process: 16 °C for 24 h, 2 °C for up to 15 days) can improve beef quality compared to conventional chilling and conditioning for all carcass grades. Since microorganisms grow rapidly at this temperature, ultraviolet lights are used to inhibit growth. If delayed chilled products are also electrically stimulated, a more consistently tender beef product can be achieved. Electrically stimulated, delayed chilled beef carcasses are more tender than non-stimulated carcasses and the sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) band pattern of myofibrils shows a more rapid breakdown of troponin T and troponin I bands than for non-stimulated carcasses. In chilled beef carcasses, the relationship between pH and colour is primarily influenced by the temperature.

It has been reported that very fast chilling (−20 to −35 °C) of beef carcasses immediately after slaughter improves tenderness at 6 days. The advantages of this extreme chilling regime are a significant reduction in chilling loss, a slower rate of pH fall and an increased perception of marbling. It also results in a darker meat colour and an increased drip loss. An increased toughness and shorter sarcomere lengths have also been found with ultra rapid chilling (−30 °C for 30 min with an air velocity of 4 m s−1) of beef carcasses, suggesting an increased risk of cold shortening.

Spray chilling of beef carcasses with an intermittent water mist (1 °C, intermittent for 4–16 h) reduces carcass shrinkage (reduced by 0.08 g per 100 g per hour of spraying), without compromising quality or increasing spoilage losses; however, there should be sufficient time after the end of spray chilling to prevent the carcass from having an undesirable pale colour and a wet surface, which would increase bacterial growth.

Stretching pre-rigor muscles during post-mortem chilling tends to increase the tenderness of the stretched beef muscles and is particularly helpful in conditions that might produce cold shortening. In the 'Tenderstretch' method an S-shaped hook is placed in the obturator foramen, and the carcass is hung from this hook, which causes the pelvic limb to hang in a horizontal position.

Organic acid sprays for both hot cattle carcasses and chilled carcasses result in pathogen reduction. Decontamination processes such as steam vacuuming, pre-evisceration carcass washing and organic acid rinsing, and hot water carcass washing are techniques that could be useful for improving the microbial quality of beef carcasses.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B012464970X002233

Beef

K.S. Ojha , ... D. Troy , in Encyclopedia of Food and Health, 2016

Carcass Grading and Evaluation

Beef carcass evaluation is generally the basis for judging the commercial value of the livestock and is consequently one of the most common quality control tests carried out in the meat industry. Carcass quality attributes include tenderness, cut size, fat cover, marbling, meat, and fat color, whereas composition attributes include salable meat yield and proportions of fat, lean, and bone. Carcass evaluation is a way to describe the quality of livestock in terms of their suitability and commercial value for various end usage including retail cut and processed meat. A number of approaches are available for the prediction of carcass composition and quality, which may also allow the grading of carcass into various categories. For example, in the United States, the beef carcass is evaluated based on the established Standards for Grades of Slaughter Cattle and Standards for Grades of Carcass Beef. According to this, quality grades are determined by marbling and overall maturity. There are eight quality grade designations: Prime, Choice, Select, Standard, Commercial, Utility, Cutter, and Canner. Prime, Choice, Select, and Standard are classified as young beef (maturity levels A and B) and must be <   42 months of age, physiologically. Commercial, Utility, Cutter, and Canner are cow grades from carcasses >   42 months of skeletal maturity. Similarly, In the European Union, adult bovine carcasses are classified according to the EUROP grid system, which is based on visual assessment scores according to the defined standards implemented by the European Community Regulations 1208/81 and 1026/91. The EUROP classification scheme includes carcass conformation scores on a 15-point scale with 5 main classes, E (excellent conformation), U, R, O, and P (poor conformation), and 10 subclasses and five main fatness scores (1 (low fatness), 2, 3, 4, and 5 (excessive fatness)) also with 10 subclasses. Mostly, carcass evaluation is done manually by trained graders using photographic references. Various carcass classification schemes adopted worldwide have been criticized due to the subjective nature of the process with a high degree of inconsistencies in such manual grade assessment. With growing concern of qualitative value of carcass and the possibility to improve the consistency of assessment, instrumented carcass evaluation techniques including ultrasound, x-ray CT, nuclear MRI, total body electrical conductivity, and video image analysis (VIA) are gaining importance in the meat industry.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780123849472000568

Removal of the spinal cord from carcasses

A.V. Fisher , C.R. Helps , in Improving the Safety of Fresh Meat, 2005

15.3 Fate of the spinal cord

Beef carcasses are split down the median plane to yield two half-carcasses or 'sides'. The reasons for doing this are pragmatic and are mainly concerned with subsequent ease of handling of the product: intact carcasses commonly weigh in excess of 300 kg, sometimes considerably more for certain breeds and categories of cattle. Boning and cutting into primal joints is commonly done on a table and this would be practically impossible if the carcass were not split. In addition, the rate of chilling in unsplit carcasses can be so slow in the thickly muscled hind limb region that certain anaerobic bacteria that may be present can multiply and give rise to bone taint ( Nottingham, 1960). The recommendation is that the temperature of the deep leg should be brought down to below 15 °C in 24 hours (James and James, 2002), which is much easier to achieve in a split carcass.

Splitting down the midline is practised because off-centre splitting runs a high risk of cutting into the valuable longissimus thoracis et lumborum muscle that runs down each side of the spinous processes of the vertebral column for much of its length. The means of splitting is, almost universally, by mechanical saw with the result that some of the spinal cord tissue is fragmented and dispersed in the immediate vicinity of the splitting station. There are different types of saw in use in the industry. Saws with reciprocating blades have largely been replaced by bandsaws that, as the name implies, have a toothed band (blade) running between two revolving wheels that are enclosed in the saw chamber. The blade width is greater in the former and the tooth design may also have implications for the amount of spinal cord that is disseminated. Circular saws with a toothed rotating disc are used for splitting cattle carcasses, but they are relatively uncommon.

We have determined the sites of contamination by spinal cord during carcass splitting (Helps et al., 2002). This was done using two cellular markers indicative of cells present in the CNS. The astroglial cell protein S-100β and the astrocyte marker glial fibrillary acidic protein (GFAP) were used to quantify levels of CNS using an enzyme-linked immunosorbent assay (ELISA). In an experimental abattoir, beef carcasses were split using a typical bandsaw and five sites on each of the lateral and medial surfaces of the carcass were swabbed using synthetic sponges (Fig. 15.1). In addition, samples were taken from polyethylene screens measuring 0.6 m wide × 2.5 m high, placed on either side of the operator at an angle of approximately 45° to the rail suspending the carcass, and from hand-held polyethylene screens measuring 0.2 × 0.3 m, positioned either side and just below the saw as it moved down the carcass during splitting. The operator's apron was also swabbed, and the saw wash water that collected in a tray beneath the carcass was sampled. The possibility of spinal cord tissue fragmenting into minute particles that could be aerosolised was investigated by using 4.7 cm open face filters operating at a flow rate of 35 litres per minute. Air flow was maintained during splitting and for one minute following the completion of sawing each carcass and filters were retrieved after the completion of five carcasses. Three samplers were positioned adjacent to the large screens, one above the carcass, one on a hand-held lance that followed the saw blade during splitting and one on the operator's chest. The highest levels of spinal cord contamination were on the hand-held screens and in the tray below the carcass. However, contamination was detected on the carcass, primarily on the medial surface with natural logarithm counts approximately 1.5 times higher than on the lateral surface. Not surprisingly, contamination was higher on the areas that included the vertebral column than on the more ventral regions, a finding also reported by Prendergast et al. (2004) using GFAP as a CNS marker.

Fig. 15.1. Schematic diagram of the five areas swabbed on the medial surface of a split beef carcass.

Following on from the work undertaken in the experimental abattoir, described above, samples were taken from a total of 660 carcasses from 51 abattoirs in eight European countries. Very similar patterns of carcass contamination were seen, with the areas along the cut vertebral surface having more CNS contamination (Fig. 15.2). Figure 15.3 shows the combined results for carcass areas 1 and 3 from the abattoirs in each of the countries visited. The levels of CNS contamination varied substantially, both between abattoirs in the same country and between countries, indicating that the causes were probably specific to the working practice in each abattoir.

Fig. 15.2. Average Glial fibrillary acidic protein (GFAP) levels from 660 carcasses for areas 1, 2, 3 and 4 + SEM (see Fig. 15.1 for area definition).

Fig. 15.3. GFAP results for 51 abattoirs from eight EU countries. The average GFAP values for areas 1 and 3 were calculated for each abattoir plotted in ranked order (highest on the left). The error bars represent SEM for n = 20 or 30.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781855739550500157

Use of meat quality information in breeding programmes

G. Simm , ... R. Roehe , in Improving the Sensory and Nutritional Quality of Fresh Meat, 2009

Marbling scores

Quartered beef carcasses are commonly visually assessed for marbling or IMF, using a subjective score awarded by trained assessors. Different scoring systems and anatomical assessment sites are used in various countries (e.g. USDA, AUS-MEAT, Ferguson, 2004). As well as predicting IMF content, marbling scores give information about distribution and size of IMF depots, which may affect the attractiveness of meat. Correlations between IMF and marbling score are generally moderate, but vary depending on the system used, amongst other factors. Nevertheless, EBVs for marbling in beef are available in USA and Australia for different breeds.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781845693435500121

Food Spoilage, Preservation and Quality Control

D.Y.C. Fung , in Encyclopedia of Microbiology (Third Edition), 2009

Spoilage of Fresh Meat

Cold stored beef carcasses : A low temperature of 4   °C and prolonged storage favor fungi growth. Spoilage by molds involved include: Thamndium, Mucor, Rhizopus which develop 'whiskers', Cladosporium ('Black' spot), Penicillium (green patches), Sporotricum, and Chrysosporium (white spot). Yeasts involved include Candida lipolytica and C. zayloanoides, torulopsis, and Rhototorula. Ground beef and hamburger are exclusively spoiled by bacteria including Pseudomonas, Acinebacter, Moraxella, Alcaligenes, and Aeromonas. Bacteria isolated from beef, lamb, pork, and fresh sausage include Moraxella, Acinetobacter, Pseudomonas fragi, Pseudomonas fluorescens, Pseudomonas putida, and 'Pseudomonads', which is a group of polarly flagellated Gram-negative rods not easily identified as Pseudomonas.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B978012373944500122X

Robotics and automation in meat processing

G. Purnell , Grimsby Institute of Further &amp; Higher Education (Gifhe) , in Robotics and Automation in the Food Industry, 2013

13.2.6 Splitting

Pork and beef carcasses are generally split into right and left sides to ease handling and increase rates of chilling. Lamb and sheep carcasses are typically left unsplit.

Automatic carcass splitting equipment has been available for many years. Systems are sold by such suppliers as Stork, SFK, Danfotech, Durand, Automeat, etc. These machines have a range of cutting actions and complexities. The basic systems use a simple downwards motion of a circular saw through the space where the carcass should be. A higher level of complexity uses a series of rollers to locally position the spine onto the cutting device.

'Back finning' is sometimes carried out as part of splitting for pork carcasses. This process reduces damage to the eye-muscle during the splitting operation by separating it from the dorsal spine 'fins' before splitting the carcass. An automated system using a relatively complex arrangement of rotary knives, plain blades and active rollers has been developed for this task in the Danish pork industry.

Automation for beef splitting was among the first examples of mechanisation in the slaughterhouse, and many equipment manufacturers now include beef splitting machines in their product range. Whilst this equipment removes the arduous manual process, many users of the equipment are still dissatisfied with its performance in terms of accuracy of splitting down the centre of the spinal column and the hygiene aspects associated with deposition of bone dust and other detritus on edible surfaces of the carcass.

The Fututech system included a module that automatically split a beef carcass into two sides using a guided bandsaw (White, 1994). Later work by Food Science Australia funded by Meat & Livestock Australia (MLA, 2012) used a robot to guide a band saw for carcass splitting. This equipment had a vertebrae sensing system based on ultrasound and this experienced difficulties on some carcasses due to voids caused by the hide puller disrupting the consistent passage of the ultrasonic wave necessary for ultrasound sensing.

Most splitting equipment producers claim an increased accuracy of automatic carcass opening and splitting over human-based splitting operations. However, the experience of some users is that there is still deviation from the precise centre line of the carcass. This can cause problems for carcass inspection and subsequent automated systems using the spine as a reference or datum position.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B978184569801050013X

Automated grading of beef carcasses

P. Allen , in Improving the Sensory and Nutritional Quality of Fresh Meat, 2009

20.3.1 European Union (EU) beef carcass classification scheme

The EU beef carcass classification scheme requires that carcasses are classified for conformation and external fat cover (Commission Regulation (EEC) No. 219/93, O.J. No. L196, 5.8.93, p18). For conformation, there are five classes denoted by the letters E, U, R, O and P, with E having the best conformation; hence it is often referred to as the EUROP scheme. Countries have the option of using an additional S class for carcasses with very superior conformation, mainly double muscled animals. Fat classes are denoted 1, 2, 3, 4 and 5, with 1 having the least external fat cover. Both conformation and fat classes may be subdivided into three subclasses. Several countries use this so-called 15-point scale while others subdivide only the most common classes. The classes each have descriptions and photographic standards. Classifiers may be employed by the state, by an independent grading organisation or by the processor. They are highly trained and must be regularly monitored by the responsible national organisation and retrained if necessary. Standards throughout the EU are maintained by an expert panel who visit each country on a regular basis to check that the grading is in line with the EU standards. The classification scheme is used by the EU to define a standard carcass for price reporting and to specify the quality of carcasses eligible for market intervention purposes. It is used by the industry for quality-based payments to producers and in buying specifications for carcass trading.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781845693435500200

Chemical decontamination strategies for meat

G.R. Acuff , in Improving the Safety of Fresh Meat, 2005

Publisher Summary

Contamination of a beef carcass with pathogenic bacteria of enteric origin most likely occurs during the slaughter process and the location and extent of contamination is extremely variable. Chemical decontamination treatments, therefore, must be applied to all surfaces of the carcass with the assumption that pathogens are universally present. While the objective of carcass decontamination may be to eliminate presence of these pathogens, the entire bacterial population is also reduced in the process. Investigations into the chemical decontamination of beef carcass surfaces have resulted in significant numbers of published accounts in referred technical journals over the last 30 years. Initial research into the decontamination of beef carcasses had as a primary goal the reduction of total bacterial numbers, resulting in a possible increase in shelf-life. If chemical decontamination procedures are to be used as a pathogen control step in a Hazard Analysis and Critical Control Point (HACCP) system, validation of control will be required. Since introduction of pathogenic bacteria into the processing environment for testing or validation of decontamination procedures is not advised, most challenge testing is performed under laboratory conditions. However, it is extremely difficult to define experimental conditions in a laboratory setting to accurately represent the conditions that actually exist on a carcass surface during typical commercial slaughter operations. Any attempt to determine an optimal carcass treatment method based on reductions reported in the scientific literature should be approached with caution and validation of chemical decontamination procedures under actual in-plant conditions will be ultimately necessary. This chapter reviews some of the more commonly used chemical decontamination agents, briefly discusses combined treatments and possible development of pathogen resistance, and suggests future trends.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781855739550500170

CUTTING AND BONING | Hot Boning of Meat

S.J. James , C. James , in Encyclopedia of Meat Sciences (Second Edition), 2014

Conclusion

Hot boning of beef, pork, lamb, horse, and poultry carcasses offers a variety of benefits to the processor such as increased boning yield and savings in refrigeration capacity and energy usage compared with conventional cold-boning operations. In addition manufacturers of further-processed products have realized the improved functionality of hot-boned muscles especially in the production of ground beef and pork items.

Common problems with early hot-boned meat systems usually included reduced tenderness, distortion of muscle shape, and darker lean color. However, the use of ES or muscle restraining and aging systems greatly reduces, or eliminates, many of these problems. Prerigor boning and chilling systems are applicable to the meat industry and provide a safe and high-quality product.

Although a number of countries, such as New Zealand and Australia, have embraced the benefits of hot boning, the lack of understanding of, and information about, hot processing, the operational changes required to make hot-boning systems work in current operations, and fear of reduced shelf-life has limited the uptake of hot-boning in other countries, especially in Europe and the Americas.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B978012384731700235X

The storage and preservation of meat: I Temperature control

R.A. Lawrie , in Lawrie's Meat Science (Seventh Edition), 2006

(b) Mode of application

The scientific literature on electrical stimulation indicates that the electrode system, the type of current (voltage, frequency of pulse and duration), the pathways (via nerve or direct) and the time post-mortem have varied considerably between investigators. Bendall (1980) comprehensively reviewed the position. Most appear to have applied the current via the thoracic region of the carcass and to have used the Achilles tendon for return to earth. Although low voltages (<   100   V) are intrinsically safer in operation, they are less consistent in effect than voltages of 500–1000   V or more (Bouton et al., 1980a; Bendall, 1980). High voltages are effective in accelerating post-mortem glycolysis when applied for 1.5–2   min, whereas longer times (~4   min) are required with voltages of the order of 100   V.

Because of differences in their intrinsic electrical resistance, intact carcasses will allow more current flow for the application of a given voltage. Thus, for example, a peak voltage of 680   V, between electrodes 200 cm apart, gave a peak current of 5.2 amps with intact beef carcasses (wherein conductivity is high because of the relatively large cross-sectional area and the presence of the wet gut contents), 3.3 amps with dressed carcasses and only 2.4 amps with dressed sides ( Bendall, 1980). The latter tend to jerk outwards since there are no contralateral intracostal or l. dorsi muscles to oppose movement (Bendall, 1978a).

In respect of other aspects of the current, optimum pulse rate appears to be between 15–25 pps (higher frequencies tend to be relatively ineffective since they fall within the latency period of the muscles concerned), and the optimum pulse width is about 20–40   ms (shorter widths may fail to activate all the muscle fibres).

The response of beef carcasses to electrical stimulation falls off quickly after about 50   min post-mortem (Bendall et al., 1976) and that of lamb carcasses even sooner. It is thus desirable to apply the current within about 30   min of slaughter.* Since isolated muscles, on the other hand, will respond as well at 3   h post-mortem as at 20   min (Bendall, 1977) it appears that in electrical stimulation of the carcass or side the musculature is usually activated via the nervous pathways. If the applied voltage is sufficiently high, direct stimulation of the muscles can occur at a later time (Chrystall et al., 1980) when decay of the nervous pathways has made low voltages ineffective. Such observations are useful insofar as electrical stimulation may not be feasible in certain abattoirs until after carcass dressing (Hagyard and Hand, 1976–77).

The importance of a still-functioning nervous system in making low voltages effective was re-emphasized by Swedish (Rudérhus, 1980) and Australian (Morton and Newbold, 1982) work. By placing one electrode in the nerve centre of the muzzle (and earthing via the Achilles tendon) during the first 10   min post-mortem, a typical acceleration of post-mortem glysolysis was achieved by applying various stimulation procedures lasting for 1   min and having a peak voltage of 80   V. A current of 14pps, applied either in 1   s pulses or continuously, was effective. Although the peak voltage was 80   V, the duration of each peak was only 5   ms, and the actual voltage very low, being thus relatively safe in operation. Australian regulations now require that the peak voltage should be 45   V. With such a system, in order to ensure that at least 95 per cent of the stimulated carcasses have a minimum standard tenderness (not more than 8   kg shear force), stimulation must be applied within 4   min of slaughter and the high resistance of the upper leg and shoulder must be bypassed by earthing via the anus or leg (Powell et al., 1983).

Another low voltage procedure is to push a plastic rod (with an electrode at its tip) down the spinal cord immediately after bleeding. The current used with this device is pulsed at 25 pps for 2   min, the peak voltage being 140   V (Bendall, 1980). Such procedures have obvious economic advantages, but not all abattoirs would be in the position to stimulate carcasses so early post-mortem.

Although the duration of the current required to achieve anaesthesia in the electrical stunning of calves and sheep (1–3   s) is much less than that involved in postmortem electrical stimulation (ca. 2–4   min) there is evidence that electrical stunning may also accelerate post-mortem glycolysis (Lambooy, 1981). The very fast cooling which electrical stimulation permits immediately post-mortem, especially with the relatively small portions of meat now produced by hot-deboning, not only avoids 'cold-shortening' but also greatly reduces microbial problems from residual blood. In such changed circumstances, electrical stunning could be used both to kill the animal and to accelerate post-mortem glycolysis in its musculature. There would be no need to have a period for anaesthesia and bleeding, and abattoir operations could be even more efficient. Indeed Geesink et al. (2001) demonstrated that post-mortem electrical stimulation of beef carcasses could be omitted, without sacrificing tenderness, when animals are electrically stunned or immobilized with a relatively low electrical input (75   V, 20   s). On the other hand, prolongation of the current for 80   s can be associated with tougher beef, partly because of sarcomere shortening in such circumstances.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781845691592500073