It’s the litmus test of whether food safety culture and procedures are truly effective.

It’s a way to stop contaminants from reaching store shelves — and to prevent costly, reputationally damaging recalls. Plus, the data is valuable for making business decisions.

“Lab testing does not make products safe — it tells you what the plant is doing effectively,” said Virginia Deibel, chief scientific officer of Deibel Laboratories, which has 15 labs across the United States. Aside from microbiology and analytical chemistry, the company has a research arm and business unit that offers training and food safety microbiological consulting.

Beyond analyzing samples to test for pathogens and allergens, dedicated testing labs answer questions about the data. They go beyond the numbers. That way, the data can be used to improve processes and mitigate food safety issues. “The whole point of collecting the data is to use it to make business decisions,” Deibel said. “The lab should help you decipher the information so you can take those results back to the food plant and have some sort of an action.”

Lab tests are a critical link in the food processing chain.

And while some of the largest corporations establish their own in-house laboratories, the cost and technical expertise required to do so can be prohibitive for small- and medium-sized businesses. Even companies with labs on site contract with third-party lab testing groups for comparative testing so they can assure that the results they are receiving are accurate. It’s a sort of checks-and-balances way of quality testing the in-house lab.

So regardless of whether you operate your own lab or partner with a service, there are some crucial steps to take when vetting a third-party provider. “You are buying competencies and science,” said Fabien Robert, senior director of Nestle Quality Assurance Center (NQAC). Here’s what to find out before you send samples to a lab for testing.

Location, Location.

When selecting a lab partner, Robert suggested visiting the lab in person so you can actually see the safety and quality protocols that are put in place. “Choosing a lab is as important as choosing a supplier, and we sometimes tend to forget that,” he said, warning against rushed decision-making to “grab a lab” that hasn’t been thoroughly reviewed. “It’s a partner you’ll work with, and the protocols of the lab you select can have an impact on your performance.”

Labs must have an open-door policy that allows for audits and verification, Robert said, “if a lab is not open to visits — no way.”

Another factor related to location is a lab’s capacity to test samples from plants located across the country, if your operation has multiple sites, Deibel said. “Then there is a greater propensity that [they] will have a lab location close enough to the plant that you can use a courier system, and that can save a day in shipping samples,” she said.

The other aspect of location to consider is where your products will be marketed and sold. When discussing testing options with clients, FoodChain ID Testing asks that question first. “We have someone who is experienced at exporting to the European Union (EU) and another who knows all of the requirements for Turkey and the Asian market,” said Diana Yepez-Aviles, marketing manager. “Technical specialists route inquiries depending on the business objective.”

Location can impact which lab tests are necessary, Yepez-Aviles said. “If you want to sell cookies in the EU, you might need a completely different testing package,” she said.

Accreditations and Affiliations.

At the very least, a lab should hold the ISO 17025 certification, Deibel said. Not all labs have this accreditation. “This is the baseline,” she said, noting that in-house laboratories might not be able to invest the time, resources and expertise to achieve the certification.

Beyond ISO 17025, labs with “flexible scope” can develop and offer tests without going back to regulatory bodies for accreditation. “We have the freedom with flexible scope to offer a test and put it out there,” Yepez-Aviles said. “So, from a customer perspective, say that a new test for genetically modified organisms (GMO) is commercialized and they want to test for that, [they] do not have to wait.”

Deibel also suggested asking whether the lab is involved in industry trade groups as a way to understand how connected the lab is to new regulations and best practices. “A lab partner should remain current with industry trade groups and have established relationships with test manufacturers,” she said.

Testing Capabilities.

Are you testing finished products or ingredients? “Some labs only test for certain sample types, so with highly processed samples or multiple ingredients, it is harder to analyze, and some labs do not have the expertise to perform that testing,” Yepez-Aviles said.

You could risk inaccurate test results, she noted, adding, “there can be a lack of consistency in results.”

For example, Yepez-Aviles said some labs might say they can test for whole soybeans — but not for soy oil or soy protein isolate. Or they can provide the test but will not quantify it. “That is when the litigations come,” she said.

Again, testing should be tied to business objectives.

If your goal is to attain a non-GMO product seal and sell into the U.S. market, this can require different tests than selling the same product to Europe.

Testing earlier in the food chain is most effective, Yepez-Aviles said. “If you are testing a final product for soy oil, if you have access to the soybeans where the oil was made, it would be best to test at that point,” she said. “Quantitative GMO analysis of a finished product can sometimes be challenging, for example, if the sample DNA has been degraded due to heat or other processing methods.”

“The whole point of collecting the data is to use it to make business decisions. The lab should help you decipher the information so you can take those results back to the food plant and have some sort of an action.” Virginia Deibel, Chief Scientific Officer, Deibel Laboratories

Companies should also include supplier monitoring and environmental testing in their plan, Deibel said. “That way, you are assessing risk across all areas where it could be present in production.”

One of the benefits of an in-house lab is the ability to have analytical testing competence internally, Robert said. “With an internal lab, you have your product and food experts, and you can combine this knowledge, because the more the lab understands about the production and can be more involved, the better the testing.”

This is why companies that hire an external lab should have internal knowledge to understand the process and capabilities and get results you can use.

But is there such a thing as too much testing?

Robert said food companies should be clear on what to test, why and what to do with the results. “If you are confident that your quality management processes are solid … you can adjust testing needs accordingly.”

The Whole Picture.

Cutting-edge technology is allowing testing to be more granular and can direct us to the root of contamination. The Food and Drug Administration (FDA) and Department of Agriculture (USDA) both use whole genome sequencing (WGS) to identify pathogens isolated from food or environmental samples. Those can be compared to samples provided by patients who are infected with Salmonella or E. coli, for example. Then, links can be made between the food production environment and even back to the field.

Deibel compares WGS to the board game Clue. “The butler killed [someone] in the library with a candlestick … so if someone complains of illness to a regulatory body or a doctor has a patient with a reportable disease, they send that to the CDC with a sample of, say, feces and they will look for Salmonella,” she said. “If they find it, they will do a whole genome sequence on that and a food review from the person or people. They’re looking for common foods, and many times they can narrow it down to food groups.”

From there, scientists can consult a database and begin identifying past reports and samples collected from plant visits, the environment or product samples, Deibel said. “If they find a dairy producer has that same type of Salmonella in their product from the environment, they might be able to link that product that caused the illness.”

It’s fairly new technology, Deibel noted. “It’s complex and expensive, but what it does is open up the whole genome to testing so you can get 100% of the genome as opposed to older technology where you really had, say, 1% of the genome and that was post-field gel electrophysical (PFGE). The whole genome sequencing is a much more powerful tool.”

But, it is one tool. And it has its place.

“It’s the evolution of science,” Robert said. “We believe you use this tool when you have to answer specific questions rather than using it by default in any circumstance. If you have a positive result and you want to understand where the contamination is coming from, it’s a very good tool.”

We see WGS being used more and more in the industry to support food safety and for regulatory purposes, Yepez-Aviles said. “This is a powerful tool for the detection, investigation and control of foodborne pathogens,” she said.

The practice is growing, she added. “Absolutely, we seem to be moving in that direction.”

Yepez-Aviles agreed there is a tendency for larger food companies to invest in their own labs. Still, she noted, the need for an experienced and accredited third-party lab partner is important for assuring consistently accurate results.

The author is a frequent contributor to Quality Assurance & Food Safety magazine.