As a result, the scientists behind the report have recommended that all samples should be analysed with at least two kits.
In the test, published in the Journal of AOAC International (2005;88(1):156-160), three commercially available ELISA test kits were given the once over to see their accuracy of testing for peanut protein in various foods.
Neogen Veratox for Peanut, R-Biopharm Ridascreen Fast Peanut, and Tepnel BioKits for Peanut Assay were put to the test on breakfast cereal, cookies, ice cream, and milk chocolate.
"All three commercial test kits successfully identified spiked and peanut-free samples," said Douglas Park and his colleagues at the FDA. "The validation study required 60 analyses on test samples at the target level 5 mcg peanut/g food and 60 analyses at a peanut-free level, which was designed to ensure that the lower 95 per cent confidence limit for the sensitivity and specificity would not be <90 per cent."
"When two test kits are run simultaneously on all samples, the probability becomes 95 percent. It is therefore recommended that all field samples be analysed with at least two of the validated kits."
Virginia based Food Allergy & Anaphylaxis Network (FAAN) estimates that 11 million people in the US - or 1-in-25 Americans - are affected by food allergies, meaning that contact with, or ingestion, of certain foods causes serious, sometimes life-threatening reactions. With no cure for food allergies, avoidance is the only way to prevent a reaction.
The Food Allergen and Consumer Protection Act (FALCPA) bill - which was pushed through Congress last August - will require tighter labeling requirements for all food makers operating in the US market from 1 January 2006.
The legislation will require that food manufacturers identify, "in plain, common language", the presence of any of the eight major food allergens - milk, egg, peanut, tree nut, fish, shellfish, wheat and soy, and was hailed as a victory by the allergy lobby groups.
The new US rules also require that the FDA conducts inspections and issues a report within 18 months to ensure that food manufacturers are complying with practices "to reduce or eliminate cross-contact of a food with any major food allergens that are not intentional ingredients of the food". Eight foods account for 90 per cent of all allergic reactions in the US, namely milk, eggs, peanuts, tree nuts (walnuts, almonds, pistachios), wheat, soy, fish, and shellfish. Symptoms can range from swelling of the lips, or tongue, shortness of breath or a drop in blood pressure and heart failure.
A food allergy occurs when the immune system mistakenly believes that a harmless substance is harmful. In its attempt to protect the body, the immune system creates IgE antibodies specific to that food. The next time the individual eats that food, the immune system releases massive amounts of chemicals and histamines in order to protect the body, thereby triggering allergic symptoms.