While the meat and poultry industry remains in a continuous improvement mode to further advance product safety, product recalls still occur due to foreign-material contamination. Fortunately, various in-plant detection technologies are available to help find unseen metal, bones and other foreign contaminants on-line.

Eagle Product Inspection's FA3/C provides inline fat measurement/contaminant detection for packaged meat in cardboard boxes, plastic crates and vac-pack frozen blocks.

Industry must find contaminants as quickly and early in the process as possible before contaminated products work their way down the line and possibly damage more equipment and contaminate more product.

Each year product recalls are issued due to foreign-material contamination. On April 4, the Food Safety and Inspection Service (FSIS) announced Tyson Foods Inc.’s Sedalia, Mo., plant was recalling approximately 75,320 lbs. of frozen, fully cooked chicken nugget products that may have been contaminated with plastic. Tyson received consumer complaints that small plastic pieces were found in their products, which prompted the recall. The contamination was traced to a product scraper inside of a blending machine.

One year earlier, AdvancePierre Foods, Enid, Okla., recalled approximately 1,200 lbs. of fried chicken breasts that may have contained small metal pieces after receiving two consumer complaints. The problem occurred after a small metal hand tool fell into a grinder, which was discovered by the company’s metal detectors. No reports of injuries were received.

Detection solutions

FSIS defines foreign material as non-animal objects, such as metal, plastic, rubber, glass, wood, steel or lead shot. The main foreign detection technologies used to detect such contaminants include metal detection, x-ray detection, visible/infrared (IR)/hyperspectral imaging systems (camera/laser-based) and mechanical, explains Richard Hebel, product manager, Fat Analysis, Eagle Product Inspection, Tampa, Fla.

Of those foreign-matter detection technologies available, metal detectors, imaging systems and x-ray inspection appear to perform the best, Hebel says. “Metal detectors are the cost-effective solution for metallic foreign material, which is also their limitation,” he adds. “Imaging systems provide detection of foreign material on exposed surfaces of meat. The most enhanced of the three technologies is x-ray inspection, which allows foreign-body detection capable of inspecting for metallic and non-metallic contaminants and presents an adequate density difference to the meat before rejecting the substandard product.”

Eagle’s customers are concerned about any harmful physical contaminant that could get into the meat or poultry during the production and packaging processes plus contaminants that existed previously in the product and were undetected in the processing stage. This includes ferrous material, such as calcified bone that can remain unidentified in products without thorough inspection.

Plastics present a serious challenge since they are undetectable with metal detectors, and their densities tend to be very similar to meat, making detection by x-ray challenging. If the meat is size-reduced, this tends to size-reduce [and multiply] the plastic, which can then entrap the plastic within the meat where it is more difficult to detect.

In some situations, using an air knife to separate loose, light materials, such plastic film or ear-plugs from meat portions may be helpful, he says. Another strategy is to use metal-detector-and/or x-ray- detectable specific personal protective equipment (safety glasses, gloves, aprons, ear-plugs, etc.) in conjunction with metal-detector or x-ray inspection systems, so they can be easily identified if misplaced within the product.

Eagle recently launched its MDX (Material Discrimination X-ray) technology, which is commonly used in airport security systems. It is an advancement over typical x-ray inspection as this inspection technology uses two, instead of one, x-ray energies, he says. MDX has since evolved to DEXA (dual-energy x-ray absorptiometry), which led to the DEXA-based x-ray systems used by meat processors for inline fat measurement. As this technology has advanced, so have the additional features and benefits of x-ray, which now include check weighing, count components and packaging defect inspection.

Eagle also offers its TraceServer, which provides a server that runs in a customer’s PC and collects inspection data and images from Eagle x-ray systems. In conjunction with bar code and lot inputs, TraceServer allows documentation of product security including foreign-material events.

Effective foreign material detection systems provide a high level of precision vigilance, alerting workers to foreign material, Hebel says. This leverages worker headcount and makes them more aware of the types and severity of foreign-material incidents enabling them to preemptively address sources of foreign material. Most product inspection technologies are also strictly password-controlled with different levels of access and authorization according to the level of management and control needed.

Various solutions

“Every contaminant and product has different properties so you need to understand the goal of each detection project to apply the technology correctly,” says Erik Brainard, president and CEO of Anritsu Industrial Solutions USA Inc., Elk Grove Village, Ill., subsidiary of Japan-based Anritsu Industrial Solutions Co. Ltd. Anritsu offers HD, UltraHD and DualX X-Ray Inspection Systems, Checkweighers, Dual Wave Metal Detection, Combination Checkweigher and Metal Detector Systems, Reject Devices and QuiCCA QA Data Collection Software.

Anritsu’s new DualX (Dual Energy) measures two different energy levels of x-rays.

“While metal is detected by a metal detector, x-ray machinery can detect metal at more accurate levels as well as glass, stones, rubber, PVC and Teflon plastics, ceramics, cement and other contaminants based on density,” he adds. “Wood and insects, regrettably, are not yet detectable.”

Anritsu’s new DualX (Dual Energy) technology measures two different energy levels of x-rays, which greatly enhances detection of lower-density contaminants including bones and stones, Brainard says.

Initial and operational costs are important aspects for the processor to evaluate in relation to the importance of assuring product quality and consumer protection. “Metal detection is the entry point for somebody to check for metal; that’s going to be the lower price point,” Brainard says. “There are two categories of x-ray technology – entry-level and high-level x-ray technology. Unlike metal detection, entry level x-ray can look inside packaged products that have foil or metallic properties to do a decent job in detecting metal. But to take detection beyond traditional size-metal detection and accurately detect wire, small metal pieces and lower density contaminants, you need to focus on higher-resolution imaging systems. If you want to go further for bone or stone detection, dual-energy technology is the highest level of inspection.”

If the goal is to protect equipment from incoming metal, processors often put a metal detector on the front end of the production line to protect the grinder or mixer from large metal contaminants, he adds. If the goal is bone detection, processors should install the x-ray system early in the process and use different technologies including dual-energy.

“Anritsu supplies dual-wave metal detection, which is in essence two metal detectors in one maximizing detection of ferrous and stainless metal independently,” Brainard says.

Anritsu’s meat and poultry customers are primarily concerned with metal and bone contamination. “Many of our consumer manufacturer customers are pushing back on their suppliers [in their detection efforts] so suppliers are trying to detect stainless metal pieces smaller than 0.8 mm,” Brainard says. “On the poultry side, finding bone is a big deal. We want to remove the choker bone [wish bone] and fan bone; using Dual-Energy technology or a Pipeline x-ray detection system is recommended.”

Dual-Energy, Anritsu’s newest form of detection technology, is utilized in different ways. It improves protection against low-density contaminants – and it’s starting to detect other contaminants. Some manufacturers are also using Dual-Energy detection for fat/lean analysis.

“If you want to find smaller contaminants, you have to go to the higher-imaging systems,” Brainard says. “You want a clear picture with clear data for analysis so go with the technology that gives you the clearest picture and ultimately the better detection with the higher operational efficiencies in terms of false positive versus your detection specification.”

Processors want the smallest footprint they can get, he adds. “X-ray can be [used for] contaminant protection, checking weight or for missing items. There is a lot that can be done in a smaller footprint that adds quality and provides processors with peace of mind. Since x-ray inspection can combine multiple capabilities within one system, it provides additional value in eliminating maintenance of additional pieces of equipment,” he continues.

Many plants are switching from metal detection to x-ray detection because higher-end x-rays will find smaller pieces of metal and provide other quality control benefits offering increased protection, Brainard says.

Metal detection

Industrial metal detector systems are sophisticated pieces of equipment, relays Geri Foley, Metal Detection sales manager, Mettler Toledo (MT) Product Inspection, Columbus, Ohio.

“A system typically consists of a detector, an operator interface and an automatic reject system. X-ray systems can detect both metal and non-metallic contaminants, as can machine vision inspection systems,” Foley adds.

MT’s meat and poultry customers typically look for the best sensitivity on stainless-steel contamination, specifically injector tips.

Mettler Toledo's Safeline Power Phase Pro Select metal detector are suited to applications where a "product effect" is encountered, such as moisture in meat or poultry..

Mettler Toledo’s Safeline Power Phase Pro Select metal detector utilizes variable frequency technology to provide the flexibility that enables vastly different products to be inspected in a single machine. These detectors are suited to applications where a “product effect” is encountered, such as the presence of moisture in meat or poultry. Its Opti-Select technology automatically chooses the ideal operating parameter from eight primary frequencies with more than 800 custom frequencies to choose from to ensure the highest levels of sensitivity are always achieved, Foley says.

The Global Food Safety Initiative has changed how its meat and poultry industry customers view metal detectors, Foley relays. The metal detector has become a critical control point in the process, which requires a shut down if there is a metal incident.

“[Detecting and preventing] metal contamination requires good recordkeeping, for which many customers are utilizing our PRODX software to help manage their metal-detection program,” Foley says. “ProdX acquires and stores data, then makes it quickly available for system analysis and improvement – and for FDA inspections if necessary.”

Robert Rogers, senior advisor for Food Safety and Regulation, Mettler Toledo Product Inspection, says the key is to determine the contamination source and to ensure corrective action is taken. “Once a source is determined, proper corrective action can be implemented, including increasing training of personnel and increasing awareness of upstream operations,” he adds.

Toronto, Ontario-based Fortress Technology offers its Stealth line of metal detectors.


Fortress Technology, Toronto, Ontario, offers its Stealth and Phantom lines of metal detectors, among other products. “Our metal detectors help our customers the most by detecting stainless-steel contaminants, in particular,” says Kelly Sharpe, marketing manager.

In April 2014, the company launched its FM software for Fortress metal detectors. Developed to be compatible with all previously manufactured Fortress detectors and can be field installed on its Phantom and Stealth models, the FM software analyzes the detection signal and uses an algorithm to calculate the signal strength based on a function of time and amplitude. This can significantly improve performance in certain applications, including large bags, by at least 40 percent, the company states.

“As far as offering protection on a critical control point, metal detection is probably the least expensive investment processors can make in their entire plant,” Sharpe says. “It’s such an integral part of food safety and their HACCP plans.”

Effective metal detection impacts the attentiveness and accountability of workers up and down the line. “Any type of detection should be making people more accountable for their actions,” she says.

Looking forward

People must understand they need to first determine what they’re trying to accomplish when planning to install any detection technology in order to get the most value from the technology, Brainard says.

“What are you trying to accomplish – advance the quality of your product or protect products by being proactive? Is that the best place for it?” he asks. “Work with your vendors and make sure you’re applying and utilizing the technology correctly.”

Customers want better sensitivity, reliability and ease of use.

“We always listen to our customers’ needs and incorporate these requirements into all of our metal-detection equipment,” Foley says. “Their input led to Power Phase Pro Select being designed specifically for product effect applications to achieve better sensitivities and to our one-pass auto setup feature.”

Government regulations, which will become tighter and tighter, will drive the detection technology evolution in the future, Sharpe predicts. “We may see increasingly comprehensive foreign-material detection and reduced total cost of ownership of the detection systems as a trend in the future,” Hebel says.

“The former addresses the desire of meat processors to reduce food-safety risks and improve the quality profile of their product; the latter addresses the practical financial picture facing processors of technology moving from limited, cost-restricted, critical-risk applications to accepted, routine implementation across all of their lines,” he concludes.