Hidden food allergens – Testing must start at food source
Food allergies are on the rise across the world in both adults and children. Allergic reactions to consuming specific food proteins can range from mild rashes and hives, to severe anaphylaxis or loss of consciousness. Given that there is no cure for food allergies, avoidance of the allergen is the only way to prevent a reaction.
Although most consumers do not show adverse symptoms to food allergens, health consequences for sensitive individuals can be severe. As a result, the Codex General Standard for the Labelling of Pre-packaged Foods specifies allergenic substances and ingredients that require compulsory declaration when present in processed pre-packaged food products.
International labelling regulations
Countries adhering to international standards are required to observe the minimum of eight allergenic substances, referred to as “major allergens”, but additional allergens are included in the list in some countries. The eight major allergens are milk, egg, fish, crustacean shellfish, tree nuts, wheat, peanuts and soybeans, or a food ingredient that contains protein derived from one of these foods.
For example, Australia and New Zealand regulations also include bee products (bee pollen, propolis, and royal jelly), while the European Union’s additional inclusions are celery, mustard, sesame seeds, and lupin. Japan prioritises the labelling of a further five allergens: wheat, buckwheat, peanut, egg and milk, but recommends the labelling of another twenty foods, including fish and seafood, fruits such as kiwi, peach, orange and banana, chicken, pork and matsutake mushroom.
Hidden allergens
While a risk of potential allergen contamination exists during manufacturing, it could also arise due to the presence of allergens in raw materials.
In the manufacturing of multi-sector bakery products, for instance, rework from pastry lines is intermittently incorporated into lower end bakery products irrespective of the inclusion of allergenic ingredients in the dough. This may result in the presence of hidden allergens in the final baked product – a contravention of local and possibly international allergen labelling legislation.
Edible oils, hydrolysed proteins, lecithin, gelatin, starch, lactose, flavours and incidental additives, i.e. food additives, may be derived from major food allergens.
Edible oils can be derived from major food allergens such as soybeans and peanuts. While the consumption of highly refined oils derived from major food allergens by allergic individuals does not appear to cause allergic reactions, unrefined or cold-pressed oils that contain higher levels of protein residues may cause a reaction.
Lecithin, which is often derived from soybeans, is a common food ingredient. Soy lecithin, which contains residual protein, could possibly prompt an allergic reaction in sensitive individuals.
Similarly, partially hydrolysed protein ingredients can elicit allergic reaction. Protein hydrolysate is often made from soybeans, wheat, peanuts, or milk protein.
Allergen risk management
Also of concern is the contamination of food ingredients at source, for example, wheat contaminated with gluten, as it could produce finished pre-packaged foods containing ingredients not normally used as a typical ingredient.
This explains the reason for precautionary statements now widely used in pre-packaged food labels: “may contain traces of…”
Clearly, food safety administrators should not only focus on scrutinising pre-packaged goods, but should apply allergen risk management in food manufacturing from the primary stage of food processing.
Primary food processing consists of the harvesting and preliminary conversion of plant and animal organisms into food, commencing with agricultural activities such as harvesting, slaughter, cleaning, sorting and grading.
From a secondary food processing standpoint, processors must make sure that HACCP programmes include the analysis of critical control points (CCPs) for allergen contamination and appropriate corrective actions to resolve nonconformity.
Testing methods
It is evident that, in addition to screening for and identifying potential allergy causing animal and plant-derived substances, it is vital for analytical and diagnostic laboratories to detect and quantify traces of contaminant allergens in food products.
Sources: Journal of Allergy Volume 2012
Food and Drug Administration
