Allergens.
A milligram of peanut protein — a crumb a fraction of a millimetre across — is enough to trigger a reaction in the most sensitive people.
A food allergy is the immune system mistaking a food protein for a threat. Reactions range from itching and hives to anaphylaxis, a whole-body reaction that can close the airway and kill within minutes; it is treated with adrenaline and emergency care. Unlike microbes, allergens are not destroyed by cooking in any reliable way, and the amounts that matter are tiny: for the most sensitive people, a fraction of a milligram of protein.
Laws therefore require the main allergens to be declared: nine in the United States (milk, egg, fish, crustacean shellfish, tree nuts, peanuts, wheat, soy and, since 2023, sesame), fourteen in the European Union (adding celery, mustard, lupin, molluscs, sulphites and cereals with gluten), eight groups in China's labelling standard. In a kitchen, cross-contact — a shared spoon, board, fryer oil or surface — carries them into food that does not contain them. The workshop weighs a crumb.
Below: the protein in a crumb of the food you choose against the reference dose that protects most allergic people (VITAL 3.0), and how many times over it is — for crumbs from a thousandth of a gram upward.
- Explain what a food allergy is.
- Name the major allergens in the US, EU and China.
- Prevent cross-contact in a kitchen.
- Appreciate how small a dangerous amount is.
Crumbs matter
A single milligram of peanut — a crumb barely visible — carries about 1.3 times the reference dose of peanut protein; a drop of milk (0.05 g) about 8 times. That is why "just pick it off" is never safe for an allergic guest, and why a spoon that touched peanut sauce, oil that fried prawns, or a board that held bread can carry enough to cause a reaction.
In practice. Ask every guest about allergies, and take the answer seriously. Know every ingredient in every dish, including those inside sauces, stocks and spice mixes (fish sauce, nut oils, sesame paste, soy in many products). Prepare the allergen-free food first, with clean boards, utensils and hands, keep it covered and apart, and do not use shared frying oil. Read labels every time; recipes change. And know the signs of anaphylaxis — swelling of the lips or tongue, difficulty breathing, collapse — and call emergency services at once.
Choose one dish you cook often and list every ingredient, then every ingredient inside those (stock cube, sauce, spice blend). Mark which of the major allergens appear. Most cooks find one they had not known was there.
Terms
- Food allergy
- An immune reaction to a food protein.
- Anaphylaxis
- A severe, whole-body allergic reaction that can be fatal.
- Cross-contact
- An allergen transferred into a food that does not contain it.
- Reference dose
- An amount of allergen protein expected to provoke a reaction in only a small share of allergic people.
Sources
- Allergen Bureau (Australia and New Zealand), VITAL 3.0 reference doses (2019), based on the ED01 eliciting doses of W. M. Houben et al.: peanut, milk and egg 0.2 mg protein; hazelnut and sesame 0.1 mg; soy 0.5 mg; wheat 0.7 mg; cashew 0.05 mg; fish 1.3 mg; shrimp 25 mg.
- U.S. Food Allergen Labeling and Consumer Protection Act of 2004 and the FASTER Act of 2021: milk, egg, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame.
- Regulation (EU) No 1169/2011, Annex II: fourteen allergens to be emphasised on labels — cereals containing gluten, crustaceans, eggs, fish, peanuts, soybeans, milk, tree nuts, celery, mustard, sesame, sulphites, lupin and molluscs. China: GB 7718 lists eight groups of allergenic ingredients for declaration.
- USDA FoodData Central, SR Legacy (April 2018), public domain.