Food allergen scanner: see allergens highlighted in the ingredient list
A food allergen scanner reads a product’s ingredient list and highlights declared allergens so they are visible at a glance instead of buried in a paragraph. FoodCheckr highlights allergens inline in the full ingredient list and can scan the printed label directly when a product is not in the database.
What "highlighted inline" means and why it matters
Most allergen tools give you a summary: a row of icons, or a list saying "contains: milk, soy". That is useful, but it loses information.
FoodCheckr highlights allergens inside the ingredient list, in place. In the app's own screenshots you can see _lait_, _orge_ and _soja_ marked within a French ingredient list, and the soy emulsifier picked out inside émulsifiant (lécithine de _soja_).
The difference matters. A summary tells you soy is present. Inline highlighting tells you soy is present as lecithin, inside the emulsifier, which is the information you need if you tolerate soy lecithin but not soy protein, a distinction that affects a lot of people.
The declarable allergens
In the EU and UK, 14 allergens must be emphasised in the ingredient list:
Cereals containing gluten · Crustaceans · Eggs · Fish · Peanuts · Soybeans · Milk · Nuts (tree nuts) · Celery · Mustard · Sesame · Sulphur dioxide and sulphites above 10 mg/kg · Lupin · Molluscs
In the United States the "big nine" are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame.
The lists differ, which matters more than people expect when buying imported food. Celery, mustard, lupin and sulphites are declarable in the EU but not in the US. An American product legally sold with undeclared celery can be a real problem for someone who reacts to it.
Precautionary allergen labelling, such as "may contain traces of nuts" or "produced in a facility that also handles milk", is largely voluntary in most jurisdictions. Its absence does not prove absence of cross-contamination, and its presence does not quantify risk. No scanner can resolve this, because the underlying information does not exist in a machine-readable form. Read the pack.
Insect ingredients and shellfish allergy
This connection is under-appreciated, so let me state it plainly.
Insect proteins are structurally related to those in crustaceans and dust mites, principally through tropomyosin and arginine kinase. EU authorisations for house cricket (Acheta domesticus) and lesser mealworm (Alphitobius diaperinus) carry a specific warning that people allergic to crustaceans, molluscs and dust mites may react.
If you have a shellfish allergy, insect-derived ingredients belong on your watch list, and this is one place where FoodCheckr's insect detection does double duty, because it was built to catch those ingredients.
The limits, stated plainly
A scanner is a second pair of eyes, not a medical device.
- It reads what is declared. It cannot detect contamination.
- Camera text recognition can miss text through glare, creasing or blur.
- Product databases can lag behind reformulations.
- Advisory "may contain" labelling is inconsistent and not reliably captured.
For a severe or anaphylactic allergy: read the physical label yourself, carry prescribed medication, and contact manufacturers when a product matters enough. Use the scanner to catch what tired eyes miss, which is a valuable job, just not the whole one.
How to check this in FoodCheckr- Open FoodCheckr and scan the product barcode.
- Scroll to the ingredient list. Declared allergens are highlighted inline.
- If the product is missing, switch to ingredient scan and photograph the label.
- Tap Analyze with AI for a written summary of the allergens present.
- Always confirm "may contain" statements on the pack itself, because advisory labelling is inconsistent and often not captured in databases.
Frequently asked
Can an allergen scanner be trusted for a severe allergy?
Treat it as a second check, never the only one. It reads declared ingredients accurately and quickly, but it cannot detect cross-contamination, cannot resolve inconsistent "may contain" labelling, and camera recognition can miss text on a creased or glossy pack. For anaphylactic allergies, read the physical label and carry prescribed medication.
How label scanning works and where it failsWhich allergens have to be declared on a label?
The EU and UK require 14: gluten cereals, crustaceans, eggs, fish, peanuts, soybeans, milk, tree nuts, celery, mustard, sesame, sulphites, lupin and molluscs. The US big nine omits celery, mustard, lupin and sulphites, which is a real gap when buying imported products.
Read the label-reading guideAre insect ingredients a risk for shellfish allergy?
Potentially yes. Insect proteins are structurally related to crustacean and dust-mite proteins, and EU novel-food authorisations for house cricket and lesser mealworm carry an explicit warning to that effect. If you react to shellfish, treat insect-derived ingredients as a watch item.
See where insect ingredients appearDoes it flag gluten?
Cereals containing gluten are among the declarable allergens and appear highlighted in the ingredient list. For coeliac disease specifically, certified gluten-free marks remain the stronger signal because they cover contamination thresholds that ingredient lists do not.
How to read a food label