Producers of ready-to-eat meat and poultry are increasingly employing infrared (IR) food-processing technologies to ensure food safety as well as optimising colour, taste and cooking efficiencies.

Using IR for pasteurisation is a relatively new process and was not a consideration for fully cooked meats prior to 2002. However, as the US began to focus on the genetic fingerprint of Listeria monocytogenes and match it with a specific production facility, it became apparent that the meat industry needed a better scientific understanding of how, and where, pathogens attached to ready-to-eat meats.

Once these cross contamination points were discovered, the question became how to solve this and alleviate the risk of food poisoning. IR filled this need better than any chemical or alternative process.

IR pasteurisation equipment is now bolstering efforts to combat the hazards of Listeria and other pathogens. The use of quick IR surface treatment of pre-cooked products can provide a log reduction of three or better. By combining short, medium and long-wave high-response IR emitters, a process can be fine-tuned to maximise product safety while also achieving the required surface finish, including the colour and texture of meats.

Often such equipment is only available "off the shelf," and is not readily adaptable to existing processes. As a result, food processors find that the end product has to adapt to the limitations of the equipment and this can affect the colour, texture, flavour, processing time, throughput and safety.

However, food processors such as poultry concern Butterball are now determined to "bend" the equipment to meet the exacting safety and food quality needs of the product through a new paradigm: cooperative engineering and innovative 3D modelling with the equipment manufacturer to streamline and improve the process.

Butterball recently added IR pasteurisation to the lines at its Jonesboro, Arkansas, and Longmont, Colorado, plants. Both 3D design and equipment customisation were major contributors to the success of this project.

"Although we were primarily interested in the food safety benefits of IR pasteurisation as well as protecting our brand, we also felt there was an opportunity to optimise the equipment in terms of human safety and ease of maintenance," says Steve Valesko, Butterball vice-president of engineering. "We also sought to incorporate automation features that would monitor equipment status and notify the operator if the IR pasteuriser was approaching a need of service."

Trial run

Valesko, a veteran of the industry, says that although he anticipated the need to customise the new IR equipment to Butterball's specifications, the engineering and production groups began the move to the new pasteurisation equipment by trying standard equipment offered by Unitherm Food Systems (Bristow, Oklahoma).

Unitherm is able to "bend" the design of its cooking and chilling equipment to ensure an optimum fit with the advanced features wanted on the production lines of many of the food industry's largest players.

"They are a major supplier of equipment to our industry and we were assured that they would work with us to tailor the new equipment to meet our requirements," Valesko says. "So we felt that test-driving' the standard equipment would both facilitate and expedite that process."

"There is a tremendous need in the food-processing industry to have access to customised equipment," explains David Howard, Unitherm CEO. "For instance, there is certainly a selection of standard IR equipment available but in order to get the results needed for food-preparation safety and other features, it is usually a good idea to engineer the equipment to best fit the customer's needs and provide the highest quality and yield of products.

"That demands a cooperative engineering effort where feedback can be turned into appropriate and beneficial design modifications that meet the needs of the end product," adds Howard.


"We ran the initial equipment for about a month," Valesko says. "And, although it was quite evident that we would need to make alterations to our final IR pasteurisation equipment design, that trial period with the off the shelf' equipment was highly beneficial. It permitted us to see the equipment in action and redesign it with Unitherm to meet the needs of both our process and our products."

The preliminary trials, held at Butterball's Jonesboro plant, entailed full production runs, checking product temperatures and ensuring that the IR pasteurisation performed the proper amount of log reduction of food-borne bacteria.

"Our basic concern was to ensure the wholesomeness of our product," Valesko says, that entailed the necessary protection of our deli products prior to sealing in the bag."

He added that some of Butterball's deli customers, including major supermarket chains, have begun to request IR pasteurisation as an assurance of safety for the meat and poultry products that they slice and sell.

Validation and further improvement

After the trial run, Butterball engineers and process people decided on several upgrades for the IR pasteurising equipment, either to meet their food safety goals or to better integrate with the process.

"What we didn't want was to change the way the equipment operated," Valesko explains. "Yet there were specific alterations that we knew would make the system much better for our operations."

Most of the alterations Butterball requested were aimed at improving human safety and ease of maintenance. They specified a change in the way the equipment hood opens and closes, so that it is more user-friendly. The outside of the trial pasteuriser would get hot, so Butterball stipulated that it be made cool to the touch. The Butterball project team also requested that the belt could be cleaned more easily.

The key to making those changes was the collaborative effort between the equipment design engineers and Butterball's engineers and process managers. Among the most noteworthy tools to facilitate that collaboration was a 3D modelling programme that Unitherm uses so that every nut and bolt of a system can be portrayed, reviewed and approved or further modified.

"The 3D modelling was one of the beautiful parts of this project," Valesko explains. "It allowed us to see exactly what the machine was going to look like. And from highly detailed 3D images we were able to make even further alterations than we would have otherwise, including structural changes to the frame of the machine to where the electrical panel was going to be located, and things like that. If it had been a typical 2D programme, we probably would not have done that."

Valesko added that the 3D illustrations helped Unitherm to cooperate fully in adapting or bending its equipment design to meet Butterball's production and quality requirements.

"We worked very well together on the project," he says. "Now we feel assured that the equipment has been designed to accomplish what we've set out to do."

He says that although Butterball was responsible for the redesign of the IR pasteurisation system, nothing about the final concept is considered proprietary.

"The improvements that we made had to do with food safety and human safety issues. Those are concerns that are shared by the entire industry," Valesko says. "So, for the betterment of the industry, we are willing to share information about our own improvements in those areas."