While the United States focuses on the “Big Eight” allergens (wheat (gluten), crustacean shellfish, eggs, fish, peanuts, milk, tree nuts and soybeans), Europe has expanded this list to 14 allergens, including those in the U.S. plus the addition of celery, mustard, sesame seeds, sulfur dioxide/sulphites, lupin, and mollusks. Both the U.S. and EU have provided guidance documents for food allergen labelling. Nevertheless, undeclared allergens continue to be a serious problem. This has forced food companies to implement not only Good Manufacturing Practices (GMPs) but also processes to ensure protection from allergen cross-contact during manufacturing. Every attempt must be made to visibly identify allergens and isolate them at every step in the process, from raw ingredients and equipment to other foods housed and/or are processed in the same facility.
With respect to one major allergen, gluten, detection has become even more complex. Gluten is defined as a complex mixture, composed of hundreds of related but distinct proteins, mainly prolamins and glutelins, and can be found in wheat, barley, rye, some oats and their crossbred varieties. It is mainly the prolamins, when digested into peptides, which trigger gluten sensitivity immune reactions, including Celiac Disease. The strongest immune response is to a prolamin fragment, an alpha2-gliadin fragment, referred to as a 33-mer or G-12. This fragment is highly resistant to breakdown by digestive enzymes, making it useful as an analytical marker in food products.