Foreign Object Detection Challenges in Meat Processing

Processing meat products presents product quality and safety challenges to food processors. First and foremost is to avoid the possibility of biological contamination through diligent sanitary processes that include harsh and frequent cleaning procedures with wide temperature swings. Food processors must also ensure the right processes and equipment are in place to avoid unwanted foreign objects entering their process at any stage, including when supplier ingredients are added.

Sentinel contaminants

Detection of such physical contaminants can be difficult with metal detection technology because meat products have high product effect that can mimic a foreign object, often necessitating a compromise in sensitivity to avoid false rejections. With temperature, salt content and product size changing during processing, product effect can vary, too, making consistent foreign object detection difficult.

Some examples of challenging meat applications are:

  • Spiced and salted processed products
  • Deli-style layered slices
  • Sausages
  • Moist or bloody whole muscle cuts
  • Ready to eat meals containing meat

Fortunately, new metal detection technology can help overcome these meat inspection challenges.

Flexibility to compensate for high product effect

Sentinel Multiscan Metal Detector

Multiscan metal detection scans use five user-adjustable frequencies at a time, increasing the probability of detection and improving overall sensitivity. When multiscan is coupled with a design to survive thermal shock, harsh chemicals, and software to adapt to constant product changes, food processors can achieve a new level of food safety previously unattainable in meat applications. This new technology is available exclusively in the Thermo Scientific Sentinel Multiscan Metal Detector.

A common approach to reducing product effect and thereby improving detection performance is to utilize low-frequency, low-energy excitation. The Sentinel Multiscan Metal Detector makes this easy because frequencies can be selected from 50 to 900 kHz at the push of a button. When a difficult product is encountered, a technician can set up a low frequency schedule better suited to a highly conductive product and optimize performance. Since this technique is not always required, the flexibility to be able to run any frequency on any product is a plus with multiscan. The Sentinel Multiscan Metal Detector typically exceeds the performance of single frequency metal detectors by 10-30%. Because the frequencies are completely adjustable, the Sentinel Multiscan Metal Detector is more flexible and can cover a wider range of applications.

Software to learn variability and adapt to changes

Autolearn Software for the Sentinel Multiscan Metal Detector

The auto learn routine in the Sentinel Multiscan Metal Detector adjusts to the change in product signal. It accepts multiple products at various temperatures both clean and with the target contaminants. To optimize set up, the data from this product then automatically sets all the operating parameters. By teaching the metal detector in this way it is possible to quickly arrive at a set up that could otherwise take a skilled technician many hours or even days to complete. 

Once in production, it is a fast process to review recent reject data to see if it is necessary to adjust a parameter to eliminate false rejects. To handle phase changes over time, the Sentinel Multiscan Metal Detector includes a phase tracking capability. Tracking works by automatically adjusting the product phase in real-time as the meat is inspected. Information from uncontaminated meat is fed back using a proprietary algorithm, maintaining performance as the ratio of conductive and magnetic product signals change. The result of this smart, adaptive software is that user intervention is eliminated and throughput is maximized. This is true even in difficult variable product effect meat applications.

Designed to survive thermal shock and harsh chemicals

Sentinel Multiscan Metal Detector offers a unique HD (Heavy Duty) option

Washdown requirements in the meat industry can be very demanding. The USDA calls for sanitation standards that can include high-temperature and pressure spray-down and use of caustic cleaners. Many metal detectors today are built to the IP69K rating (80˚C water at up to 1450 PSI), but this alone does not provide long-term defense from water intrusion into the metal detector case. The Sentinel Multiscan Metal Detector offers a unique HD (Heavy Duty) option for the meat industry to maximize uptime in harsh environments. It was tested and survived up to 10,000 thermal shocks with no degradation in performance.

The HD design enhancements are:

  • Soft epoxy fill and liner resistant to separation from the metal case
  • Complete fill with epoxy eliminating space where water could be trapped
  • Welded aperture flanges to reinforce the liner seams

How to detect non-metallic contaminants

Foreign objects such as bones, stones, plastics and even glass will pass through a metal detector undetected because the contaminants are not metallic. X-ray inspection is therefore the only possible option for foreign object detection. X-ray inspection works by detecting differences in density and thickness within the product. It can find many common conductive AND non-conductive contaminants. Sensitivity, however, requires a detailed product test because some contaminants like bones and plastic can be challenging due to their low density. Metal detection performance with X-ray may also exceed that of a metal detector. Many times the inspection equipment must be IP69K rated. Fortunately, the Thermo Scientific Xpert series of X-ray systems is available to meet the need for X-ray inspection in a meat application.

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