Food Safety Inspection of Pet Food Products
 

Product effect occurs when a product has a conductive property which affects the magnetic field generated by the food metal detector. This is typically found in high salt, high moisture product environments. For example, wet cat food will show significantly more product effect due to its high moisture and salt content. This negatively impacts the metal detector’s ability to distinguish between actual non-ferrous metal contaminants and the false signal given by the combination of typical product attributes. In these situations, industrial X-ray inspection equipment will produce significantly better results since product effect is not a factor.

There are several points in the pet food production process that benefit from food safety inspection (metal detectors, X-ray inspection) and checkweighing technology. Here are some examples.

1. Incoming ingredients. Large pet food producers may require that their vendors meet specific HACCP objectives and provide proof of inspection. Even with those methodologies in place, some will also inspect incoming ingredients. Typical incoming inspection consists of drop through and bulk flow metal detectors.
2. After mixing/rendering. Processing equipment such as an industrial blender or mixer will age over time and potentially introduce small particles or shavings of metal into the product being processed. It is important to position inspection equipment after this process equipment to catch any contaminants as early in production as possible, so it doesn’t affect final product quality as well as damage equipment further downstream. The inspection equipment type will depend on the product type and whether its formulation creates a “product effect.” Wet or moist pet food products are more suited toward X-ray equipment, while metal detectors perform well with dry or kibble type pet food products.
3. After filling/packing. The recommended inspection equipment type is dependent on the packaging material or combination of materials that have been selected for this product. Metal components such as aluminum foil trays, metal cans, aluminum foil bags or metalized firm structures are much more suited to X-ray inspection. Flexible materials without a metal component, paperboard folding cartons, bags or pouches work very well with either metal detectors or X-Ray inspection systems. At this stage, checkweighers are frequently used in combination with a metal detector or X-ray inspection system to ensure product weight matches information printed on the product label.
4. After case packing. After case packing is another good inspection point as this is the last stop before the finished products leave the facility. The recommended inspection equipment type is dependent on the packaging material of the individual product. This is typically done via X-ray inspection. In addition to contaminant detection, the X-ray system’s ability to detect missing pieces will help ensure that the specified count has been loaded into the case. In certain situations, especially when X-ray inspection is not included at the end of the line, checkweighers are placed here to ensure that the proper number of packages are contained inside the case.

Metal detection works very well with dry/kibble pet food and treats that do not have a product effect that wet or moist pet foods do. Metal detection equipment provides reliable, cost-effective protection from even the smallest metal contaminants found in pet food production anywhere in a process. If the packaging material contains metal, x-ray inspection would be the right choice. In addition, if there are other contaminant concerns such as stone, high density plastic or glass, X-ray inspection systems will detect these contaminants as well.

Since wet or moist pet foods have a high product effect, X-ray inspection is the best technology to detect contaminants such as metal, glass, stone, and other dense foreign objects.

To ensure pet food processors are not under or overfilling packages, checkweighers are used to verify the correct weight of each package. Accurate weight avoids giving away costly product or from receiving hefty fines from regulatory bodies for underfilling.

For pet food products in cartons, cans, bottles, or pouches, a chain checkweigher offers line speeds up to 700 packages per minute. It is appropriate for both dry and wet environments.

X-ray inspection of packaged and bulk food products is proven to be extremely safe. There is no documented evidence of adverse health effects of X-rays on equipment operators, the food products that travel through the equipment, and ultimately, the pet consuming those products.