A common sight at the end of most food and beverage processing lines is an inspection system. Depending on the product being produced, these machines can either be X-ray or metal detection, and in some instances, a combination of both. An X-ray system detects materials like glass, bone, rubber, stone, plastic, and some metals depending on density, while a metal detection system is calibrated to identify all types of metal based on their magnetic and conductive properties.
The strategy behind placing a detection system at the end of a processing line is that once an item is packaged, no new contaminants can be introduced, so inspecting after packaging is a final safeguard before distribution to customers.
However, the number of food and beverage product recalls has increased in recent years, which can be partially attributed to an unreliable supply chain for ingredients—resulting in unfamiliar, alternate suppliers being used when materials are scarce—and an influx of inexperienced workers on the lines due to the ongoing labor crisis. As a result, major retailers like Costco are pushing processors in 2023 to expand their overall detection capabilities further up the line to catch contaminants before the packaging stage.
Adding inspection upstream can provide additional food safety protection to consumers. But the cost of adding machinery, coupled with a possible lack of space to install that equipment, are the main reasons this idea hasn’t previously taken root throughout the industry. Now, with retailers feeling pressure from consumers over recalls, that urgency is being transferred to the processors.
“Many [retail] brands are demanding specific inspection steps be performed prior to product being sent to them by suppliers,” says Marco Azzaretti, director of marketing for Key Technology. “This trend has been growing in conjunction with consumers’ increased attention to the quality and safety of food products, which in turn has made food safety incidents and recalls more common and more costly for brands to absorb, both in terms of operational costs to correct and the impact on the brand’s reputation.”
For manufacturers who worry about the upfront cost of adding inspection to their existing lines, Geri Foley, product manager, X-ray, for Mettler Toledo, offers this perspective: “The average cost of a product inspection product is somewhere between $25,000 to $135,000 depending on the technology. One product recall can be in the millions.”
While the food safety benefits of adding inspection equipment further up the line are numerous, there are also hidden savings over time to a facility that processors might not see immediately.
“The cost of a reject [further upstream] is much lower vs. rejecting finished product or anything further along in the process,” says Eric Garr, regional sales manager for Fortress Technology. “Also, consider that rejecting one larger contaminant upstream, may mitigate a much higher quantity of rejects downstream if that contaminant is broken down into smaller fragments. Further, there would likely be some fragments too small to detect with end-of-line inspection.”
Catching contaminants in the early stages can also save wear and tear on equipment as items are processed down the line. “Larger contaminants, like bigger pieces of metal or stone, if removed at the front end, can protect equipment such as grinders, mixers, and fillers that are located further downstream,” says Lanel Menezes, sales director, USA at Mettler Toledo Product Inspection. “Ultimately, non-conforming product is rejected prior to value being added through packaging.”
Sustainability goals are another benefit of adding inspection upstream. Overall food and packaging waste will be reduced if a contaminant is detected early, rather than at the end when packaged goods would be thrown out. In addition, today’s inspection systems are built with energy savings in mind, so adding this equipment to a line won’t use as much power as in years past. “This is accomplished in a multitude of ways such as deploying energy-efficient X-ray generators, using magnetically driven motors, using LED lights instead of incandescent bulbs, reducing heat dissipation from the machines, and more,” Menezes says.
An inspection system can go almost anywhere along a processing line, but there are certain areas where processors can maximize the detection capabilities of their equipment, depending on the product being produced.
“At every stage throughout the process, inspections can be conducted, starting with raw material receiving,” says Robert Rogers, senior advisor for food safety and regulations at Mettler Toledo. “Liquid products can pass through a metal detector or X-ray pipeline system, and dry goods can pass through metal detection systems. In the batching area, large container product can pass through inspections as they are dismantled into smaller batch materials, like a 50 lb bag of flour, through a throat metal detector as it is being weighed into a batch-level item.”
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Raw material receiving is a logical place to add an inspection system, since that’s where many contaminants can be introduced from the outside. “Inspecting raw product at receiving allows the input to the line to be profiled, which helps optimize downstream processes,” Azzaretti explains. “Along the production line, placing inspection systems and sensors before and after critical transformative steps such as frying, baking, and blanching allows processors to collect valuable data that can be used to control those processes and maximize line performance.” Inspection right before packaging can be another useful area of placement, he adds.
In addition to metal detection and X-ray options, digital sorters can also be used when processing raw ingredients at the front of a line. “Today’s optical sorters are more capable in differentiating with consistent accuracy what is good in-spec product, what are product defects that need to be managed, and what are foreign material contaminants that must be removed from the product stream,” Azzaretti says. “At the same time, these modern inspection systems are designed to be much easier to use and maintain.”
A shorter learning curve to use today’s inspection equipment is a crucial advancement given the ever-dwindling labor pool and the need for new hires to learn as quickly as possible. “Introducing a new piece of equipment into operations will have an impact on your employees and it is important to ensure that the necessary support is given for them to adopt the technology and trust it,” says Menezes. “This means providing the necessary training, ensuring smooth integration, collecting feedback for improvements, and ensuring ease-of-use and serviceability.”
Simplified operation on today’s inspection equipment can include touchscreens and icon-based use, which helps companies “with high turnover, or in some cases not enough individuals in the workforce,” Foley says.
Installation and innovation
Though it’s possible for a manufacturer to adjust its budget to purchase additional inspection systems, it might be more difficult to find room within a facility to place those systems. Many processors have limited footprints in their plants, so custom-engineered equipment can be one path to overcoming those challenges.
“It is important for food processors to engage closely with inspection system suppliers and express their specific requirements, because every line in every plant is unique, even when processing the same product type, and the inspection system should be tailored to each instance to maximize value,” observes Azzaretti.
Combination systems are becoming more popular because they reduce the footprint over multiple standalone systems, Garr notes. “Also, specific to metal detection, something to consider is that the aperture size and resulting metal-free area will dictate the minimum overall length for a system,” he says. “So, ensure that metal detection apertures are as small as possible, fitted for the product that is being inspected.”
Not all product inspection equipment will require additional space, according to Foley. “In many applications, the equipment can be inserted into the existing line space whether using the customer’s existing material handling solution or replacing a section of their existing line with product inspection equipment,” she says.
Calibration and testing of new inspection systems upstream is also a vital step before finalizing installation, especially since inspection will be new to those parts of the line. “Prior to making a purchase decision, it is essential to validate and measure the performance of the system through application tests that replicate the actual product and production conditions in which the equipment will operate,” says Azzaretti.
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Today’s inspection systems feature a variety of innovations, and while not designed specifically for upstream placement, they are helpful for processors to maximize their investment. “First and foremost is the ability to detect varied, ever-tinier contaminants, as well as the capability of defining when contaminants are introduced into the production process,” says Kelvin Binns, food and CPG director for Wipotec-OCS.
“Inspection systems for contaminant detection have become more powerful in terms of what they can detect,” Garr says. “To put it simply, the technology is being doubled up to cover holes and improve performance. Metal detectors operating multiple simultaneous operating frequencies and electromagnetic field orientations are innovations that help improve performance. Similar is true with X-ray inspection where dual-energy detection is allowing detection of less dense contaminants than was possible in the past.”
Connectivity and data collection are also features that can help processors make sense of target inspection areas further up their lines. “The ability to pull live data into plant monitoring software and ERP [enterprise resource planning] systems is becoming more of a prerequisite than ever before,” Garr explains. “This makes sense as having live data to make on the fly operational decisions can be invaluable.”
Menezes adds, “We live in a connected world that demands transparency. Traceability [of ingredients] and connectivity are becoming vital requirements in the marketplace.”
Ultimately, processors will have to weigh their financial and facility footprint options before adding one or more inspection systems upstream to comply with recent retailer demands. Assessing the big picture might help make that decision a bit easier. “Product inspection should play a central role in any manufacturer’s production line upgrades,” Binns says. “Leaving it out of an upgrade budget may leave a food producer out of a retailer’s supplier network.”