Treating animal carcasses after slaughter is one of the most important steps that can be taken to ensure meat products are safe when they reach the consumer. But preliminary and basic steps – sanitation procedures taken with livestock both before and after slaughter, as well as sanitation standard operating procedures required by US Department of Agriculture (USDA) regulations – are just as important, as are good manufacturing practices (GMPs) that are carried out daily in meat and poultry slaughter and processing facilities.

Sanitation at this stage of meat and poultry processing, from slaughter to fabrication, has been researched and utilized for quite a few years now, said Jeffrey Sindelar, PhD, professor of Meat Science and Animal Biologics Discovery, and Extension Meat Specialist at the University of Wisconsin – Madison (UW).

“Sanitation treatments ‘back up’ in a sense, by beginning while the animal is still alive, then through harvest, evisceration and all the way up to fabrication,” he said.

For most of the industry, it is really the harvest-through-fabrication stages that are critical. Sindelar explained that historically, sanitation has been driven by the Pathogen Reduction Act (PRA), allied with Hazard Analysis Critical Control Point (HACCP) programs and a number of directives from USDA’s Food Safety and Inspection Service (FSIS). This was a massive redo of meat and poultry inspection in the United States, both at the federal level and in states that retained state inspection. Before the PRA and HACCP, and the onset of antimicrobials, efforts were limited mostly to testing. Of course, testing remains an important part of sanitation and dealing with pathogens today.

Birko’s Head and Tongue Wash system allows processors to effectively wash heads and tongues while using less water.(Source: Birko)

“Most commonly, carcass treatments have been done with organic acids, or hot water washes or some types of pasteurization somewhere during the process. But it also can begin with treating the hides of the live animals before slaughter, and that can pose some challenges, because such treatments can be expensive to administer, and don’t always offer a return on time and cost. Nevertheless, the treatments can be very helpful as an intervention on the harvest floor, and during the sanitation process,” he said.

He emphasized that even when using chemical antimicrobial treatments and water washes, the use of traditional sanitation methods at this critical stage, from slaughter through evisceration through fabrication and even beyond, traditional sanitation and hygiene remain critical.

“Also, the USDA requirements outside of HACCP and pathogen reduction – Sanitation Standard Operating Procedures (SSOPs) using GMPs (Good Manufacturing Practices) – remain extremely important at this stage of meat and poultry processing,” Sindelar said.

SSOPs are written procedures a meat or poultry slaughtering or processing establishment develops and implements to prevent direct contamination or adulteration of products, including procedures before and during its operations. Sanitation procedures help plants to meet the USDA regulatory requirements of Part 416 – Sanitation. A new sanitation model for industry was developed in September of this year and is being publicized and encouraged by USDA.

As part of his extension responsibilities at UW, Sindelar works with small and very small slaughterers and processors. “In a way, I’m like an intermediary, helping them find protocols and solutions to problems. I try to help them think outside the box.”

Antimicrobial intervention

In carcass cleaning, there are differences between small and large processors. “Carcasses go to fabrication after antimicrobials in the large industry. In small plants, antimicrobials are used more in trimmings destined for ground beef and other products, for example,” Sindelar said

He emphasized antimicrobials are not the “end-all,” but a tool to get there. And research continues because there are no foolproof interventions. “So, E. coli can be reduced, more than eliminated. It’s important in our industry to understand the risks, how animals are raised and housed. Also, the dangers arising in different geographical regions, the seasons of the year – all these factors affect how antimicrobials and sanitation are carried out. For all these reasons, the harvesting stage is one of the most people-intensive and critical activities that takes place in the meat industry,” he said.

Cleaning animal carcasses after slaughter, as well as treating the carcasses with antimicrobials, play a major part in preparing animal carcasses for conversion into meat and poultry products, whether they would be value-added products or commodity products, said Elis Owens, director of technical services for Birko Corp., based in Henderson, Colo.

Birko’s Elite 360 electrostatic system reduces pathogens on meat and poultry. (Source: Birko)

There are a number of pathogens of concern on animal carcasses after animal slaughter. “On beef carcasses, we’re talking about E. coli O157:H7, E. coli non-O157:H7, Salmonella in poultry and hogs, and Campylobacter in poultry,” Owens said.

There is a great deal of emphasis on using antimicrobial treatments on carcasses, as well as employing hot water washes. But he thinks increased efficiency by slaughterers and processors has become a high priority in the meat and poultry processing industry.

“It is very important for slaughtering and processing companies to try and reduce the amount of water and chemicals they are using in their efforts to increase sustainability. A current trend in the use of antimicrobial carcass treatments or water washes is trying to take steps to reduce the amount of water or chemicals in slaughter and processing plants.

“There is no getting around using water and chemicals in food processing, they are critical for food safety. But there are several areas where resources could be used more efficiently. Less water could be used in carcass washing cabinets, and chemical mixing for antimicrobial treatments could be controlled better,” Owens said. “If chemicals are diluted incorrectly and applied wrong – you could be wasting chemicals if the concentration is too high. Or not achieving proper food safety standards if the concentration is too low.

“By doing this, slaughterers and processors can improve food safety standards and achieve major cost savings,” he said. “Using precision application technologies, you can improve both efficiency and the efficacy of what you’re doing using the same chemicals.”

He outlined some of the antimicrobial agents used to kill or inhibit the growth of microorganisms in food in the industry today, without leaving any residues in final products. They include organic acids like lactic and citric acids.

“There is not a lot of new development or new chemistry here. But there has been a challenge for companies and plants because some export meat products to Japan, for example, who restricts what processors can use. We have interventions approved in Japan,” Owens explained.

The technical services director outlined several antimicrobial products, including Beefxide, a new lactic/citric acid blend to spray on beef carcasses, organ meats, primal cuts, and trim, effective against E. coli and Salmonella. Others include Chicxide, Porkxide and Lambxide for poultry, pork, and lamb.

Owens also talked about a major advance in food safety methodology: electrostatic application technology to deliver antimicrobials to carcasses, trim, and carcass parts.

“The electrostatic application optimizes the chemical application you’re using on the carcass to kill any pathogens that may be there,” he said, explaining how the process works. “An electrostatic charge is applied to the chemical solution, say an organic acid. What happens is the solution spray is attracted to the surface of the meat. So, this results in an improved coverage of the product (meat) surface. At the same time, you are reducing the amount of the antimicrobial solution used. What this means is that large poultry and meat processors can use smaller amounts of chemicals and water.”

Birko’s Elite 360 is an electrostatic system that reduces pathogens on meat and poultry, reduces the amount of chemicals applied and wasted and reduces water usage. “Wastewater treatment costs are lower, it satisfies current best plant practices in hygienic design, and of course, increases food safety,” he said.

But more traditional methods of sanitation are still being used. “Carcass wash cabinets are employed, because it is important to wash carcasses,” Owens noted. “Debris can be on the carcass sides. There is still great interest in washing the animal, and when the hide is removed, washing the carcass surface.”

He said the company has developed a new head and tongue wash which will be used beginning next year.