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Improved Techniques of Slaughtering and Meat Processing
2002-06-01

Abstract

Training course on the slaughtering of cattle, pigs and poultry, and processing of their meat
The general improvement in the living standards in the Asian and Pacific region during the last few decades, coupled with the rapid development of the food industry, has meant a change in consumption patterns. Asian people are eating more meat. For example in Taiwan, annual per capita meat consumption has increased by 45% over the last 20 years. A similar trend is seen in other countries in Asia. Some of this meat is being sold fresh, but a great deal is being processed into cured or cooked meat products.

This week-long training course emphasized the practical aspects of operating a slaughtering and processing plant. It also discussed new technology and practical skills for processing livestock and poultry meat. The training course provided an excellent forum for the exchange of experiences, knowledge and new ideas that could benefit the livestock industry and consumers in Asian and Pacific countries.

A strong message from the training course was the need to address common regional concerns facing the livestock industry. These include the impact of WTO, and the safety and quality of animal products and by-products. Animal welfare is another important issue. Consumers are concerned that meat production does not involve unnecessary suffering to animals from inhumane methods of handling and slaughtering.

A number of important points were emphasized in the Training Course.

Hygiene in Slaughtering and Cutting-up of Carcasses

Customers expect that the meat they buy has been obtained from healthy animals, and slaughtered under conditions which ensure elimination of diseased materials and freedom from contamination and adulteration. All slaughterhouses must implement a hygiene management system, regardless of the scale of their operations. In fact, such a system must be in place even before production begins. Any microbiological or chemical contamination might be a health threat, either immediately or in the long term.

Good manufacturing practices need to be established. Standard sanitation procedures should be written down, displayed on notice boards, and implemented as part of the plant hygiene management program. The building design and equipment setup, cleaning and maintenance, water management, employees' training in plant operations, and meat product management, should all conform to government regulations.

Quality Management in Meat Processing: The Haccp System

HACCP, or Hazard Analysis Critical Control Point, is a proactive process control system. It is designed to prevent the occurrence of problems by assuring that controls are applied at any point in a food production system where hazardous or critical situations could occur. The HACCP system was developed by the Pillsbury Company as part of its research into food for the United States' space program. It was made public in 1971 during the National Conference on Food Protection. Since then, many countries around the world have adopted it.

The HACCP, as a preventive system to correct problems before they affect the safety of the food products people actually consume, covers seven principles, namely:

  • Hazard analysis and assessment;
  • Determination of critical control points (CCPs);
  • Establishing critical limits for CCPs;
  • Monitoring critical limits;
  • Correcting deviations from critical limits;
  • Establishing an effective record-keeping system; and
  • Verifying that the HACCP program is working correctly.

Detecting Food Pathogens by Dna Probes and PCR Primers

Rapid methods for the detection of food pathogen such as Salmonella spp., Escherichia coli and Staphylococcus aureus are very important. They allow us to trace the source of contamination in outbreaks of food-borne illness more quickly than in the past, so the outbreak can quickly be halted.

DNA methods are among the most promising techniques. They include the use of DNA probes, PCR primers and possibly in the future, DNA chips. The success of DNA methods, however, relies on specific DNA or oligonucleotide probes and PCR primers, which have to be developed separately for each target organism.

The training course described several approaches for the development and use of DNA probes and PCR primers. A number are now available which can detect various pathogenic species of bacteria. Even more useful would be a system which can detect a number of different pathogenic organisms at the same time. A number of multiplex PCR systems have been reported, but the range of target organisms they can detect is limited.

Recently, under various whole genome projects, the genome sequences of several food-related microorganisms or food pathogens have been described. This is a promising basis for the development of improved DNA probes and PCR primers for pathogenic bacteria.

Development of Products from Deboned Meat

The restructuring concept involves transforming the secondary parts of the carcass into high-value products which sell at a reasonable price, and have eating characteristics similar to those of the solid muscle steak and chops. In the 1970s, Urschel Lab announced their success in making restructured real steak with low-cost secondary carcass parts. A universal comminuting machine, the comitrol of which had been used to slice and flake vegetables, was used. The cost of obtaining the flaked and formed product was about 50% of that for the solid muscle product. At much the same time, meat scientists at the University of Nebraska were developing a flaked and formed pork steak. Today, fast-food chains are offering a wide variety of restructured red meat, poultry, and seafood products throughout the world. The most successful products are McDonald's Chicken McNuggets and Pork McRibs.

The primary rationale for restructuring meat is to transform relatively low-value carcass parts into products that have an increased market value. The restructuring processes also makes it possible to create a wide range of products. In addition to the fabrication of steaks and chops, restructured meats can be formed into dice, sticks and nuggets of any shape or size. Not only is restructured meat cheaper, but its cooked yield and nutritive value can both be predicted more accurately

One problem associated with restructured meats is oxidation, which turns meat rancid. However, this may be remedied by the use of nitrite, phosphates and other metal chelators, ascorbate and antioxidants, or by smoking. There may also be color problems. Variation in the color of restructured meats occurs unpredictably, with splotches of green and brown among the red-brown color desired. There may also be an excessive amount of connective tissue (probably the major economic concern to the producer of chunked and formed products), while retailers may be reluctant to sell restructured meats. Most flaked, chunked and formed products are retailed as frozen products.

Development of Intermediate Moisture Meat Products

Intermediate moisture meats (IMM) are among the oldest preserved foods of human beings. One of the oldest methods of meat preservation is to reduce the water content to a level at which the growth of microorganisms is prevented or greatly reduced. Many of the preserved meats made around the world are sun-dried, or heated in an oven to achieve the necessary reduction in water content. Others are made by mixing into the meat ingredients which reduce water activity, such as salt or sugar with other humectants.

One of the principles of making IMM is to depress water activity by incorporating water-soluble substances. The water activity level at which microbial activity is effectively inhibited is affected by a number of other factors, including the nature of the solute, the pH, the presence of chemical inhibitors and the nature of the microbial flora.

Utilization of by-Products

Traditional markets for edible meat by-products have gradually been disappearing, because of health concerns and the low economic return. Instead, meat processors have been developing non-food uses for these products, using them in pet food, pharmaceuticals, cosmetics and animal feed. The available literature indicates that by-products (including the blood, the bone, the organs, the fat or lard, the skin, the feet, and the contents of the abdomen and intestines) are 66% of the live weight of cattle, 52% of the liveweight of pigs, and 68% of the live weight of lambs. More than half these animal by-products are not suitable for normal human food, because of their unsuitable physical or chemical characteristics.

A valuable source of potential revenue would be gained if the meat industry could increase its utilization of meat by-products. The cost of live animals often exceeds the selling price of their carcass. It is the value of the by-products which must pay for the expense of slaughter, and generate the profit of the slaughtering operation. It has been suggested that 7-12% of the income from slaughter results from the sale of by-products. In addition to the economic benefits, the efficient utilization of meat products means that there is less water and air pollution from slaughterhouses.

Today, many new techniques are available for more efficient processing and utilization of by-products. This is important, because competition from imports is increasing. The Asian meat industry must increase its efficiency and reduce its costs if it is to remain viable.

Conclusion

A common problem in the region's meat industry is the lack of well-trained staff to perform the varied activities at slaughterhouses and processing plants. There is also a scarcity of good-quality slaughterhouses and cold storage facilities. Those that exist in a particular country are not evenly distributed, so that some livestock-producing areas have none at all.

To enhance global competitiveness, the region's animal industry should work with governments and the private sector to develop policy reforms related to importation, trade and pricing of inputs. Support in terms of technology and infrastructure should also be provided to the livestock and poultry sector.

Despite the problems besetting the livestock and poultry industries, it is apparent that these industries can be globally competitive given the right environment and support. Investment into animal breeding, feedlot technology, and processing livestock into high-value meat products will greatly enhance productivity and efficiency. Investment into processing must include the construction of modern abattoirs and cold storage facilities, and the use of refrigerated delivery vans. Marketing improvement is also an urgent task. Such investment will complete the integration of Asian livestock production with the meat processing industry.

International FFTC Training Course on the Slaughtering and Processing of Livestock: Focus on Cattle, Swine and Poultry

Held at the Taiwan Livestock Research Institute, Hsin-Hua, October 22-26

Co-sponsors: Council of Agriculture, Executive Yuan

Taiwan Livestock Research Institute

No. of countries participating: 6 (Korea, Malaysia, Philippines,

Taiwan ROC, Thailand, Vietnam)

Six lecturers; Five laboratory advisors/assistants; Eleven trainees:

Index of Images

  • Figure 1 Inspecting Meat before It Is Processed

    Figure 1 Inspecting Meat before It Is Processed

  • Figure 2 Processing Deboned Meat into Sausages

    Figure 2 Processing Deboned Meat into Sausages