Foreign Body Detection In Food Inspection — Aiming For Zero

By Melissa Lind, contributing writer

Today’s technology offers a wide range of choices when it comes to detection of foreign objects in food production. Choosing the right system depends largely on the product, packaging and processing systems, but the key is knowing what type of foreign body is most likely to enter a given food product

Foreign body contamination is the main reason for product rejection and the source of many recalls. This poses a public safety threat but also threatens your bottom line as you may lose consumer confidence and customer loyalty. Technology for foreign body detection in the food supply continues to evolve and there are a number of choices. The best place to begin is identifying the most-likely culprit.

The probable type of foreign body contamination will depend largely upon the type of food being processed. Using Hazard Analysis and Critical Control Points (HACCP) will help you identify the main areas of problem, in part based on your product and line specifics. Knowing the main type of contaminant you are looking for identifies the type of technology that you will need.

• Wet food often has conglomerations which may respond well to X-ray systems
• Repackaged food may lead to foreign object contamination which may be identifiable with more simple optical methods
• Dry foods may have metal contaminants which may respond to X-ray but may require metal detection
• Liquids may require scanning electron microscopy (SEM) or energy dispersive spectroscopy (EDS) to determine a specific type of globule contaminant

The second most-common issue in foreign body contamination is processing line equipment, which may benefit from in-process systems to prevent contamination. Pneumatic and gravity filling equipment tends to face less process-caused contamination, but may see more outside sources of contaminants.

Machines, such as milling and grinding equipment, will likely face contamination from moving metal parts that may be removable with magnets placed at various stages, while liquid products will require filtration at various points in the line. Identifying areas of weakness can help put prevention mechanisms in place to avoid contaminants slipping through detection processes.

Establishing a baseline is important. Regulations may require certain mechanisms, but there are often no limits established. For example, HACCP may require metal detection, but regulations may not specify how much contamination is acceptable. In addition, “acceptable” regulatory contamination limits may vary widely from food to food — if established at all. If a baseline is not established, detection systems have little relevance as a means to judge success. Baselines may vary from product to product and will need to be established by your company for each type of food that you process.

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While it may seem advantageous to rely heavily on automated prevention and detection systems, don’t fall into the trap of discounting manual detection. Humans may not be able to identify the same types and sizes of contaminants that technology “sees,” but there is value in manual detection. Be aware that manual detection is subject to employee training and fatigue can factor into its effectiveness, but the additional time taken to simply look at the product far outweighs any disadvantages. It is not a standalone system by any means, but it cannot be eliminated.

Aiming For Zero
No matter how many preventative measures you take or how many detection systems you implement, there will be some slip through. Accepting this unpleasant fact is a part of food production, but food manufacturers should aim for zero defects — but at an absolute minimum, need to meet baseline requirements.

Proactively identifying and measuring problems being detected will improve processes. Once the normal is established, any bumps or sudden changes in quantity or type of contamination will allow you to establish a timeline and trace back to the source of contaminants. Issues such as lack of maintenance, recent configuration, sourcing changes, or new personnel can be identified and correctly addressed.