Food Allergen Testing

The National Institutes of Health estimates that 6–7 million people in the United States suffer from food allergies. Eight foods or food groups—milk, eggs, peanuts, tree nuts, fish, crustacean shellfish, soybeans, and wheat—are responsible for an almost 90% of all food allergies on a worldwide basis according to the Food and Drug Administration’s “Guidance Document for Food Investigators.”

The allergens in these foods are naturally occurring proteins. The symptoms experienced by food-allergic individuals range from hives and mild gastrointestinal upsets to life-threatening anaphylactic shock. This means that food processors must be careful in informing food allergic consumers about the presence of food allergens in their products.

Potential problems can occur if a food allergen is present in a food product and it is not labeled. Section 403, Title 21, of the Federal Food, Drug, and Cosmetic Act requires food labels to bear a complete listing of all the ingredients in a food. However, because of a narrow exemption from the ingredient labeling requirements, several allergic-type incidents have occurred. According to FDA, the only exemption to labeling requirements is found in section 403(i)(2) of the Act; it provides that spices, flavors, and certain colors used in food may be declared collectively without naming each. In some instances, these ingredients contain sub-components that are allergens. Therefore, FDA strongly encourages the declaration of any allergenic ingredient contained in a spice, flavor, or color.

FDA has increased its efforts over the past three years to address the management of food allergens in food processing plants. The agency has actively sought industry cooperation in making significant strides to improve food allergen identification on the food label.

Currently, according to FDA, many of the suggested changes to the food label have been voluntarily adopted by the food industry. FDA is currently considering whether it is necessary to clarify its regulations to ensure that manufacturers fully understand the circumstances in which allergenic food ingredients must be declared and to ensure that sensitive individuals are protected by appropriate labeling.

Although food manufacturers label the ingredients in their products in accordance with these existing regulatory requirements, the Food Allergy Issues Alliance, a private group composed of industry, trade group, and consumer representatives, has formulated guidelines for the labeling of foods that contain known allergens. The guidelines recommend the use of terms commonly understood by consumers (i.e., “plain English”) for major food allergens within, or in immediate proximity to, the ingredient declaration, to provide clear communication with the food-allergic consumer.

The major food allergens referred to by the guidelines can cause serious allergic reactions in some individuals and account for more than 90% of all food allergies. The major food allergens are peanuts, soybeans, milk, eggs, fish, shellfish, tree nuts (almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts), and wheat. The guidelines state that it is important to disclose all allergenic ingredients regardless of the source. They also give procedures for the use of “Supplemental Allergen Statements,” commonly known as “may contain” labels. These labels are used when there is a chance that foods that do not contain a known allergen as an ingredient may inadvertently come into contact with an allergen during processing. A prominent example would be a processing line that makes a product containing peanuts and then switches over to make another product.

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Information on these initiatives is available at FDA’s Web site on allergens, www.cfsan.fda.gov/dms/wh-alrgy.html.

FDA’s current stance on allergen labeling is that manufacturers should first adhere to good manufacturing practices (GMPs), which are essential for effective reduction of adverse reactions. However, the agency has stated that precautionary labeling with statements such as “may contain (insert name of allergenic ingredient)” may be used.

According to FDA, the most difficult aspect surrounding food allergens involves GMPs. The agency’s staff Compliance Policy Guide, “Sec. 555.250 Statement of Policy for Labeling and Preventing Cross-Contact of Common Food Allergens,” provides extensive information on the regulatory issue, with a focus on good manufacturing and Hazard Analysis Critical Control Points programs for food allergens. It can be found online at www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg555-250.htm#3.

Important updates on the topic of allergens will be presented during a symposium entitled, “Allergenicity of Food Ingredients,” at this year’s IFT Annual Meeting & Food Expo® in Chicago, Ill., on July 12–16. The symposium, sponsored by IFT’s Toxicology & Safety Evaluation Div. and moderated by S.L. Hefle and S.L. Taylor of the University of Nebraska, Lincoln, will be held on Sunday morning, July 12. A. Munoz-Furlong of the Food Allergy & Anaphylaxis Network, will discuss consumer concerns about allergenic food ingredients. K.J. Falci of FDA will give an update on the regulatory issues surrounding food allergens. S. Hefle will speak on the allergenicity of ingredients derived from known allergenic sources. S. Taylor will talk about clinical approaches to evaluate the allergenicity of ingredients. And D.J. Sjrypec will address industry approaches to ingredients derived from allergenic sources.

More information on food allergens can be obtained from the Food Allergy Network, 10400 Eaton Pl., #107, Fairfax, VA 22030 (phone 703-691-3179). The network is a nonprofit organization established to increase public awareness about food allergies and anaphylaxis. Its Web site, www.foodallergy.org, includes information on product recalls and research summaries.

Allergen Test Kits Available
Manufacturers may test final products for the presence of allergens in products not intended to contain allergens. Manufacturers will need to determine what method of analysis is used, the sensitivity of that method, and whether the testing is routine or periodic.

Several commercial enzyme-linked immunosorbent assay (ELISA) kits and other assays for food allergens are commercially available. FDA is currently evaluating some of these kits and is also cooperating with kit manufacturers to conduct international collaborative studies to evaluate the performance of some of the ELISA-based methods.

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• Tepnel BioSystems’ BioKits Peanut Assay Kit is said to be the first allergen test to be granted “Performance Tested Method” status by AOAC International’s Research Institute (AOAC-RI). The company says that the test is suitable for a wide variety of raw materials and processed foods and uses enzyme immunoassay to detect minute levels of peanut (< 0.1 ppm) even in highly complex food matrices. The assay was evaluated for testing a variety of food matrices (cereals, confectionery, baked goods, ice cream, etc.), precision, detection limits, false positive/negative rates, robustness, cross-reactivity, stability, and lot-to-lot consistency. For more information, contact Tepnel BioSystems, One Newtech Square, Deeside Industrial Park, Deeside, Flintshire. CH5 2NT, UK (phone 01244 280202; fax 01244 288402; www.tepnel.com).

• Neogen Corp. offers several ELISA tests for the detection of allergens in food products. The Veratox tests for egg allergen, milk allergen, and peanut allergen are said to require only a minimal amount of training to use, and provide fully quantitative results. The Alert screening tests for egg, milk, and peanut allergens provide qualitative results in about 30 min. The Alert test for sulfites is said to offer a simple, reliable, and inexpensive method for routine monitoring for sulfite residues in seafood throughout production and distribution. For more information, contact Neogen Corp., 620 Lasher Pl., Lansing, MI 48912 (phone 800-234-5333).

• The Food Allergy Research & Resource Program was established in 1995 at the University of Nebraska-Lincoln’s Food Processing Center to assist the food industry with issues associated with food allergens. The group is developing assays to detect allergenic food residues that might contaminate other foods. Currently, the research is focused on ELISAs that detect residues of allergenic foods rather than food allergens and are useful for detecting allergenic food residues arising from such food industry practices as using shared processing equipment or using rework. Assays currently available include peanut, egg, casein, almond, and whey in selected foods. The group is also testing assays for soy, clam, hazelnut, walnut/pecan, and cashew. For more information, contact The Food Allergy Research & Resource Program, 143 Industry Complex, Lincoln, NE 68583 (phone 402-472-4484; www.farrp.unl.edu).

• Elisa Technologies, Inc. offers an assay based on highly specific antibodies to an allergic protein purified from peanuts (Conarachin-A). The assay, developed in collaboration between the UK Institute of Food Research and Cortecs Diagnostics, Ltd., is marketed as the Elisa-TekJ Peanut Protein Test Kit. It uses the principle of enhanced enzyme immunoassay (EIA) and is a sensitive and specific test designed to detect very low (ppm) levels of peanut content in raw and cooked foodstuffs. The assay is a noncompetitive, sandwich-type EIA.

Besides the peanut assay, the company offers kits for the determination of specific food proteins and ingredients, including wheat, soy, milk, and egg proteins. Gluten, soy, casein, and whey protein kits may be used to qualitatively detect the respective proteins, or, using a microplate reader and the included standards and controls, the assays will provide quantitative results. The gluten kit has AOAC Official First Action status and is used to identify gluten-free foods. It can detect gluten down to 50 ppm in 5 min. For more information, contact Elisa Technologies, Inc., 4581-L NW 6th St., Gainesville, FL 32609 (phone 352-337-3929).

• Genetic ID has developed a series of new PCR-based allergen tests for food manufacturers, distributors, and retailers. The company claims that these tests are capable of detecting the presence of as little as one or two allergen marker molecules within the DNA found in the food sample. The company’s Quick-Check Allergen Test Series is available for detection of peanuts, soy, wheat, and seafood, including shellfish. The seafood series is of particular interest, since few other service providers have the capability of detecting all classes of seafood, including freshwater and saltwater fish, clams, oysters, muscles, shrimp, and lobster. In addition, the tests are capable of specifically determining the presence of any of the seafood classes listed. Tests are also under development for tree nuts. For more information, contact Genetic ID, Inc., P.O. Box 1810, Fairfield, IA 52556-9030 (phone 641-472.9979; 877-366-0790; fax 641.472.9198).

by JAMES GIESE
Internet Editor