Selecting the Right Test for Raw Materials, Cleaning, and Finished Products is Key

For my generation—growing up in the United States in the ’60s and ’70s—most of us didn’t know anyone allergic to any food, and now it seems like food allergens afflict people all around us. “We do believe that food allergies are growing in prevalence,” says Steve Taylor, co-founder and co-director of the Food Allergy Resource and Research Program (FARRP) at the University of Nebraska-Lincoln.

“Some might be due to increased awareness, so more people pursue the belief that they might be allergic to some food.” Also, news stories about people getting sick from allergens in foods might make the situation seem even worse. Nonetheless, Taylor believes that the food industry is doing a pretty good job of ensuring that people don’t eat things that give them an allergic reaction. That success depends on extensive technology and using it in the most effective ways.

The growing number of people with food allergies is part of the problem, and the intensity of the reactions are troublesome. “The reactions are growing in severity too,” says Taylor.

How a person reacts depends on the individual and the allergen. “Individuals have variable levels of sensitivities to foods,” Taylor says. With peanuts, as little as 1/800th of a peanut can make some people react, and others might need to eat ten peanuts to notice. Once a person passes the threshold, the reaction can be just as severe— regardless of the level of sensitivity. For people with very low levels of sensitivity, the danger is worse because it takes so little—say, a speck of peanut dust— to set off a reaction in them. That means that the food industry must give those people every opportunity to avoid something that makes them sick, and the culprit can come from unexpected places. As Richard Brouillette, food safety director at New Orleans-based Commercial Food Sanitation, an Intralox company, says, “I am allergic to fish and once had an allergic reaction eating a grilled cheese sandwich at a restaurant.” He adds, “I suspect preparation surfaces or utensils were not properly cleaned between the time the fish and my grilled cheese were cooked.”

Strategic Steps

"At Commercial Food Sanitation,” says Brouillette, “we take a structured approach to allergen changeover validation, which can be summarized in three steps.” The first step is verifying the process in a food-processing plant to determine what equipment could come in contact with an allergen. “Once we are certain that all the equipment has been identified,” Brouillette explains, “we are ready to perform a post-cleaning inspection.” In the second step, he says that they “visually verify the equipment for cleanliness before taking any swabs or sampling products for allergen testing.” Once everything is visually clean, the company moves to analytical testing.

For the third step, Brouillette says, “We will test a sample of the allergen to make sure the validation method can detect the allergen.” They also test “the product containing the allergen to confirm that it can be detected in the finished product.” They “identify and sample parts of the process to confirm the effectiveness of the cleaning method to remove the allergen.” As this shows, a very methodical approach is required to ensure consumer safety.

Enforcing Allergen Safety

In the mid-1990s, Martin J. Hahn, a partner at Hogan Lovells in Washington, DC, got involved with the legal issues behind food allergens, and he helps clients comply with the Food Allergen Labeling and Consumer Protection Act and allergen controls noted in the U.S. Food and Drug Administration’s Food Safety Modernization Act (FSMA). When asked about the most complicated regulatory challenges related to allergens in foods, he says, “Most of them come from recalls due to undeclared allergens.” In the food business, an undeclared allergen is present in a product but not listed on the label. Hahn adds, “That’s an issue that the food industry has been struggling with for probably two decades, and we still see lots of it.”

Undeclared allergens get into foods in various ways. It could just be a mistake, where the allergen wasn’t supposed to be in the product. Also, the allergen could be known to be in the food but mistakenly left off the label. In some cases, the wrong label goes on a product, so the listed ingredients don’t match what’s really in the food. Cross-contamination in a supply chain or manufacturing operation can also introduce an undeclared allergen.

FSMA requires a food safety company to put preventive controls in its safety plan to reduce the odds of an undeclared allergen getting into a food product. “Companies will need to identify the controls that they have in place when necessary to control food allergens— from the supply chain and in the manufacturing process as well,” Hahn explains. This might involve looking for places where allergens can be inadvertently introduced into the supply chain or ensuring that allergens don’t end up where they shouldn’t be in manufacturing. “FSMA is intended to force companies to come up with a program that will—hopefully—be more successful and create a better match between formulas and labels and what’s in the food,” Hahn says.

Reducing Errors

No matter what governments require, some mistakes will happen; however, companies need to be as vigilant as possible. “Good companies learn from their mistakes,” Hahn says. “When a wrong label gets applied to a product, for example, they will put a control in place.” Some food manufacturers, for instance, use an optical scanner to check the label on every product to increase the odds of getting it right.

In other cases, food companies use commercially available assays to test for allergens. Maybe a manufacturing line needs to be cleaned and tested for some allergen. Taylor and his colleagues recently tested some commercially available enzyme-linked immunosorbent assays (ELISAs) that are supposed to test for milk residues. “The key thing that we looked at was the specificity of those assay methods,” Taylor explains. “What do they really detect?”

These tests look for milk proteins, which include caseins and whey. There are several casein proteins and two main whey proteins—alpha-lactalbumin and beta-lactoglobulin—in milk. Some assays claim to detect the total milk protein, meaning the caseins and whey proteins. Others might claim to detect just beta-lactoglobulin. Taylor’s team determined what an assay really detected.

“None are good at detecting alpha-lactalbumin,” Taylor says. “So even if an assay calls itself a total milk method, it doesn’t detect this one.” So a food producer needs to select the right assay—the one that fits the task at hand—and be sure that it does what it claims to do.

Although it’s difficult to completely test an assay, Taylor suggests at least using a positive control to be sure that the assay works. With assays that use test strips, too much of the analyte being detected can overload the test, which looks like there was nothing there. “Different strips overload at different levels,” Taylor says. Some might overload at 1,000 parts per million, others take 10,000 to 25,000 parts per million to become overloaded. The user needs to know when a strip overloads in order to get a real result from a positive control. If a strip assay’s literature doesn’t say when it overloads, ask the manufacturer.

Quantitatively Clean

To ensure that a food production line is cleaned of potential allergens, tests must be used, such as those made by Hygiena in Camarillo, California. Lauren Roady, Hygiena’s marketing manager, says that her company provides “tools to ensure that cleaning procedures effectively remove allergenic contaminants from the environment for the prevention of cross-contamination from uncleaned surfaces during food manufacturing.”

Part of FSMA, Roady explains, requires food producers to “verify and validate that their procedures, such as sanitation, are effective at mitigating and preventing risks, such as allergenic contaminants.” She adds, “The basic tools in a food safety manager’s tool set for accomplishing this verification are adenosine triphosphate, ATP, sanitation monitoring test kits, rapid color-changing protein residues tests, and ELISA-based test kits for specific allergens.”

Roady explains that Hygiena’s SuperSnap is an ATP surface test that when used in combination with the company’s “EnSURE monitoring system can detect extremely low levels of ATP on surfaces in 15 seconds.”

According to Barbara Hirst, a consultant for food safety and quality at UK-based Reading Scientific Services Ltd. (RSSL), “The key message here is to choose the right sampling strategy based on a thorough risk assessment, and then choose the right allergen to test for.” She adds, “This is especially important in a cleaning validation where a target allergen is usually selected and then a lab is selected with the appropriate expertise in this area that can advise on which test to use.” Although she points out that an ELISA is the “method of choice for many allergens if a suitable ELISA test is available,” she adds that “it needs to be undertaken by a laboratory with appropriate expertise.” For example, Hirst says that ELISAs “need to be used carefully, as they are subject to cross-reactivity and matrix interference, which can result in both false-negative and false-positive results if not used correctly.” Hirst and her colleagues can help a food producer select and use the right tests—from ELISA to rapid testing and more—for anything from raw materials and cleaning to finished products. As she says, RSSL provides “a range of training and consultancy services for the food manufacturing and catering industry.”

To ensure food safety in terms of allergens, producers often must rely on other companies and experts to use the right procedures and testing. Otherwise, grilled cheese triggers a fish allergy!

Lab scientists must work carefully to ensure that undeclared allergens do not end up in foods.Image courtesy of RSSL

Kits that test for adenosine triphosphate (ATP) can reveal allergens on surfaces.Image courtesy of Commercial Food Sanitation