Food Engineering

Best Practices for Allergen Control

March 1, 2002
Food manufacturers improve allergen control strategies as recalls rise.

Food product recalls for unlabeled allergens have steadily risen during the past decade, averaging 90 per year during the late '90s and reaching 121 in fiscal 2000. "I'm not sure, but there may be several reasons for the rise in allergen recalls," says Dr. Kenneth J. Falci, director of the Office of Scientific Analysis & Support at FDA's Center for Food Safety & Applied Nutrition. "It may be because both FDA and food companies are looking harder for allergens, because allergic consumers are becoming more aware of the allergens in foods, and because of improved allergen-detection methods. But the actual number of food products containing undeclared allergens is probably higher than the number of recalls."

SSOPs can render equipment surfaces “visually clean” but there’s currently no method of immediately detecting allergen residues on clean surfaces. ELISA tests can validate the effectiveness of SSOPs. (Source: FARRP, University of Nebraska)

Severe reactions

Food allergies are abnormally heightened responses of the immune system to naturally occurring proteins which are resistant to heat, digestion, proteolysis and acid. More than 90 percent of food allergies are caused by proteins in the "Big Eight" food groups: peanuts, tree nuts, milk, eggs, soybeans, finfish, shellfish and wheat. Between 2 and 2-1/2 percent of the U.S. population, or six to seven million Americans, are sensitive to food allergens. Sensitivity probably varies with the individual, but the threshold dose required to cause a reaction is very low. Symptoms range from gastrointestinal (nausea, vomiting, diarrhea), cutaneous (hives, eczema, dermatitis) and respiratory (asthma) to the most severe reaction -- anaphylactic shock, which affects several organs including the heart and can cause death in 10 to 15 minutes.

Recent research suggests that 29,000 hospital emergency-room cases and 150-200 deaths per year are caused by inadvertent consumption of foods containing allergens. "I would argue that every one of these deaths, and every one of these severe reactions, is a preventable situation," said Dr. Steve L. Taylor, head of the food science department at the University of Nebraska and co-director of the university's Food Allergy Research & Resource Program (FAARP), during a videotaped webcast sponsored by the Institute of Food Technologists (IFT) last October.

Some companies have decidedly improved their allergen-control methods, Taylor told Food Engineering. Typically, these are larger manufacturers who have assigned the high priority and devoted the resources needed to improve allergen control.

Dr. Thomas D. Trautman, senior principal scientist/toxicology at General Mills, outlined GM initiatives to control food allergens on the IFT webcast. "The greatest need we have right now is to make people more aware of this important issue," said Trautman. "Products with unlabeled allergens are not only dangerous but are misbranded and therefore illegal according to the Food, Drug & Cosmetic Act."

Veratox ELISA tests developed jointly by FARRP and Neogen Corp. are currently available for detecting casein (milk), albumen (egg) and several proteins in peanuts. (Source: Neogen Corp.)

Best practices

Food scientists and toxicologists at major food manufacturing firms concur on "best practices" that should be implemented at each stage of production to prevent undeclared allergens from getting into finished food products. Basic allergen-control strategy adopted by General Mills, said Trautman: "Dedicate, Separate, Label." Dr. Daniel J. Skrypec, director of worldwide toxicology at Kraft Foods, cites a similar strategy: "Separation, Sortation, Scheduling and Labeling."

R&D/Product Development: In formulating new products or reformulating existing products, it might be possible to eliminate allergenic ingredients, "especially small amounts which have little or no functionality," Skrypec advises. If an allergen can't be eliminated, said Trautman, perhaps it can be added toward the end of the process. He cited an example at General Mills where, instead of adding nuts to the dough early in a cereal process, the nuts were added during the enrobing stage at the end of the line to minimize that portion of the line which had to be allergen-cleaned.

Engineering & System Design: Dedicated production lines are the preferred strategy at General Mills, said Trautman. For large-volume production runs, this obviates the possibility of mixing products containing allergens with those that don't. Where more frequent changeovers are required, however, it's sometimes possible to dedicate certain portions of a line. "For example, enrobers or packaging machines that are hard to clean can be moved in and out as modules" to create "a semi-dedicated line." Many food plants weren't designed with allergen control in mind, Trautman continued. Common problems include conveyor crossover points, where product on the upper conveyor can drop into the conveyor below. This can be prevented by covering the conveyors. "Hang-ups," where product residues can collect to be swept-up in a later production run, might be contained for cleaning by isolating or sealing-off allergen-addition points on the production line. Maintenance tools are potential sources of cross contact. Ecolab (St. Paul, Minn.) suggests color-coding tools to specific plant areas or production lines.

Raw materials and ingredients: Trautman advised requiring full ingredient lists from suppliers, especially where allergens might be sub-components of flavors or processing aids, and developing a thorough understanding of raw material sources. "Does our walnut supplier, for example, also handle almonds?" Vendor certification programs and periodic vendor audits can help assure that allergens are properly identified in raw materials and ingredients, adds Skyrpec.

Production scheduling "is a key strategy and a powerful tool" in allergen control, says Dr. George E. Dunaif, director of toxicology and analytical services at Campbell Soup Co. Best practices can include longer production runs with minimal changeovers for high-volume products. Where changeovers are necessary, products containing allergens can be scheduled last in a production cycle to minimize the possibility of cross contact as well as line areas requiring cleanup. For example, "if you're producing two types of bread, one containing nuts and the other nut-free, run the nut-free first," he advises, preferably toward the end of a shift just before a major cleanup. Dunaif also recommends introducing an allergenic ingredient as late as possible into the process. "Functionality and food science will often dictate when an ingredient has to be added, but the later it can be added the better." Flexible manufacturing, which typically involves shorter production runs of different products with frequent changeovers, opens possibilities for more mistakes "but I believe a balance can be struck," says Dunaif. "If you must make more changeovers, you must be more vigilant."

Rework should be segregated and identified in dedicated containers or controlled storage areas to prevent cross contact and/or addition to the wrong batch. Skrypec and Dunaif cite the same rule: "Like-to-like." Rework totes and containers should be color-coded or labeled to identify their contents, then tracked and "signed-off" to document their use. General Mills plants, said Trautman, will often discard rework after a long product run "because we believe that storing allergen-containing rework for later use is an accident waiting to happen."

A researcher at the Food Allergy Research & Resource Program (FARRP) at the University of Nebraska adds cleaning solution to a COP (clean out of place) tank. The tank, heated by steam injection, has water jets to maintain turbid water movement during the cleaning cycle. (Source: FARRP, University of Nebraska)
Labeling and packaging require tight controls to assure that the right product goes into the right package -- that the ingredient listing matches the product. Mistakes can occur, for example, when a product is reformulated but the package is unchanged, or when a mixed load of cartons is received from a supplier. Discard older, out-of-date packaging, Dunaif advises -- "use it or lose it." Where overwraps are used, he adds, both containers and overwraps should be code-dated so product identification information isn't lost when the overwrap is discarded. Implement a tracking system and conduct mock recalls to understand where products go should an actual recall ever be required, he advises.

Sanitation starts with GMPs (good manufacturing practices and SSOPs (standard sanitary operating procedures), but there is no way of determining if a cleaned equipment surface is free of allergen residues, so "visually clean" is the industry standard. ELISA (enzyme-linked immunosorbent assay) tests jointly developed by FARRP and Neogen Corp., however, can be used to validate the effectiveness of a cleaning program. According to Tim Hendra, diagnostic sales manager at Neogen Corp., the assays detect specific proteins (casein in milk, albumen in egg, several in peanuts) which trigger antibodies to them, causing a color change relating to the amount of allergen in the sample. A simplified screening format (Alert) triggers a positive/negative allergen response sensitive to 5 ppm, while the standard format (Veratox) allows full quantification of the allergen down to 1 ppm, both in just 30 minutes. In a study conducted by Ecolab to determine the effectiveness of two detergents in removing milk protein from a stainless-steel mix tank in an ice cream plant, ELISA testing at FARRP detected no protein residues after the detergents had been correctly applied.

ELISA tests developed by FARRP are commercially available from Neogen for detecting peanut, egg and milk proteins, said Taylor. "We have in-house methods for whey and almond, are nearing completion of a test for walnut, and are working on a number of other ELISA tests as well," he added. Of these, the highest demand is for soybean. "We're making some progress," Taylor reported, "but animals don't want to make antibodies to soybeans, probably because they have so much soy protein in their diet that they don't feel it's foreign."

A 'HACCP-like' approach: Allergens should be evaluated as part of a hazard analysis, and a "HACCP-like approach" can be taken to prevent undeclared allergens, says Skrypec. Process areas identified as high risk might then be considered critical control points. "Putting the right product in the right package is often considered a critical control point," he adds.

Training: All sources contacted by Food Engineering emphasized the importance of employee training. "One of the most sensible things food companies have done is to develop cross-functional allergy teams which can address a number of issues," says Taylor. Adds Skrypec: "I can't say enough about allergen awareness and training at all levels of the corporate structure."