Salmonella reduction in poultry plants requires a team approach

Representatives from Tyson, George's and Butterball discuss how teams in their facilities evaluate poultry plant processes to reduce Salmonella numbers on broiler and turkey carcasses and parts.

Okeefe T Headshot
iStockphoto.com I iLexx | Poultry processors employ physical, thermal and chemical interventions during processing to remove and/or kill Salmonella cells that are attached to poultry carcasses and parts.
iStockphoto.com I iLexx | Poultry processors employ physical, thermal and chemical interventions during processing to remove and/or kill Salmonella cells that are attached to poultry carcasses and parts.

Poultry complexes have made headway in their efforts to deliver live broilers and turkeys to the plant with lower Salmonella loads, but the percentage of live birds that are Salmonella-positive and the Salmonella load on individual birds can vary greatly from flock to flock. Processing plants must have systems in place to effectively process all of these flocks in a manner that will result in very low incidences of Salmonella on carcasses and parts day in and day out, no matter the incoming Salmonella load.

Bill Potter, vice president technical service and quality, George's Inc., said that if you start with a flock delivered to the plant that is 100 percent Salmonella-positive and you employ a series of interventions, each of which reduces the Salmonella incidence by 50 percent, it would take seven interventions to reduce the Salmonella incidence to less than 1 percent. He told the audience at the Poultry Federation's Salmonella Summit that processors need to use a multi-hurdle approach to get the low percentage of Salmonella-positive carcasses and parts that they are looking for.

Taking a team approach with Salmonella Initiative Program

Karen Washburn, quality assurance manager at Butterball's Carthage, Mo., plant, said that in 2007 her plant became a participant in the United State Department of Agriculture's Salmonella Initiative Program, SIP. She said an SIP team was formed at the plant that included key operators, technicians, supervisors and management. The first step in the process was conducting baseline studies to develop a history, and she said they looked at post-chill carcasses, parts and ground products. "We looked at what was working, where we had vulnerabilities and where we could add interventions," she said.

Potter and Andi Ward, food safety and technical auditor, Tyson Foods, both echoed Washburn's endorsement of teams as being an important part of a successful Salmonella reduction program in the plant. Washburn said that Butterball's other three slaughter facilities now also participate in SIP and that any successes at one plant are shared with the others.

Start with biomapping

Reducing Salmonella numbers on ready-to-cook poultry products starts with understanding your processes and knowing how they impact Salmonella. Biomapping, taking microbial samples of birds or parts before and after each processing step, provides data for evaluating current practices and then later for evaluating changes.

Because incoming Salmonella counts on live birds may already be low, Ward suggested using aerobic plant count (APC) samples when biomapping. APC tests are easy to run and will have higher counts, which allows for better evaluation of interventions added further along in the process.

Salmonella interventions

Interventions to reduce Salmonella loads on poultry carcasses and parts can be physical, chemical or thermal. Brushes used to clean birds prior to entering the scalder and water washes or rinses are examples of physical interventions. Potter said that pre-scald brushes can be a useful tool and that about 70 percent of the U.S. broiler industry is currently using them.

The temperature of scalder water is an example of a thermal intervention for Salmonella reduction. Some companies are also utilizing chemical scalder treatments to help control Salmonella and find them to be effective if the organic load in the chiller is not too high, Potter said.

Chemical interventions

A number of chemical interventions are being employed by broiler and turkey processors in the forms of dips, deluges, rinses and sprays at many different locations in the picking room, evisceration, and in post-chill cutup and deboning processes. Ward said that poultry processors must walk a tightrope balancing compliance issues versus the bottom line. Processors must meet performance standards for Salmonella and Campylobacter, but they must also consider the cost of chemical interventions as well as the impact that these chemicals may have on product quality.

When choosing an antimicrobial intervention, Ward said the impacts on worker safety, efficacy, cost, floor space in the plant, organoleptic impact of the finished product, wastewater and water quality must all be taken into account. She said you also need to consider the ability of the antimicrobial intervention supplier to deliver and consider possible patent infringements and Food Safety and Inspection Service (FSIS) approval. Processors need to look at the concentration level of the chemical used and make sure the level is covered by the patent and approved by FSIS.

Washburn said that Butterball uses chlorine, acidified chlorine, citric acid, calcium hypochlorite, peroxyacetic acid and sodium hydroxide as chemical interventions in evisceration at some or all of its slaughter plants. Some of the differences in chemicals used between plants are the result of incoming water chemistry at the plants, plant preferences, different bird sizes and baseline study results.

Butterball uses interventions in sprays at the rehang table, brush cabinets and inside-outside bird washers, according to Washburn. She said Butterball spent a great deal of time evaluating which interventions work best for the company in its immersion chilling systems. At this time, all of the Butterball plants are using peroxyacetic acid in the chiller system, and the switch to peroxyacetic acid gave Butterball's Salmonella reduction efforts a big boost.

Peroxyacetic acid also plays a role in the chiller sanitation program at two of the company's plants, which now hold water in their chilling systems for up to five days. This program means that chiller water is colder at startup, and this aids in microbial control. Butterball's Mount Olive, N.C., plant processes heavy toms, and the industry's largest immersion chilling system was redesigned to get the carcasses below 40 F, which requires a dwell time of about six hours.

Control cross contamination

Salmonella control isn't just about chemical interventions; doing a good job in sanitary dressing of the carcasses and minimizing cross contamination is important as well. Potter suggested using a team approach to take a fresh look at potential areas of cross contamination. The pickers, picker finger type and design, rehang tables, evisceration equipment sanitation, adjustment and maintenance, hand washing (especially during carcass sorting), and employee equipment hygiene should all be studied.

After the chiller

Potter said that 75 percent to 80 percent of the U.S. broiler industry uses some kind of post-chill antimicrobial intervention as either a dip or spray.

Butterball uses sprays for thighs, breasts, wings, drums and skin, and materials going to ground turkey and mechanically separated turkey (MST) are sprayed as well. Various products are used in the post-chill sprays, and each facility uses bromine, peroxyacetic acid or trisodium phosphate.

Results show reduction in Salmonella

The results of Butterball's efforts to reduce Salmonella numbers both pre-harvest and in the plant have been impressive. The incidence of Salmonella-positive carcasses found in post-chill tests performed by the company at all four of its slaughter plants was reduced by more than 90 percent from 2006 to 2012. Post-chill tests administered by the USDA show a similar decline. Similar significant declines in the incidence of Salmonella positive ground turkey and MST samples in tests conducted by Butterball have been experienced.

Ward presented data that showed how Tyson evaluates its plants and biomaps processes within plants. It was evident from data presented that Tyson has made significant progress in reducing the incidence of Salmonella on post-chill broiler carcasses in the last 5-10 years.

Potter said that the U.S. broiler industry's Salmonella performance is better, but that it is "not there yet, especially on parts and processed products." He said that Salmonella performance standards are becoming more difficult to achieve and that more interventions will likely be needed. He suggested processors be flexible when configuring and designing processing lines and said management should be supportive of budgeted costs for microbiological sampling and testing, as it has to be done. The industry needs to recognize this as a cost of doing business. 

Page 1 of 33
Next Page