Allergen is one of the most frequent causes of allergic reactions and provokes hypersensitivity immune responses:

Type I 

• Immediate hypersensitivity. Involves the antigen binding to IgE immoglobulin antibodies 

Type IV 

• delayed hypersensitivity. Involves T lymphocytes that play a key role in the immune system and are co-responsible for the secretion of cytokines

Food allergy is an immune reaction that occurs in relation to exposure to a given food.

Food allergies are increasing all over the world, and generate research efforts to find a safe and adequate cure.

Certain allergenic products or substances that cause allergies as defined in EU Regulation 1169/2011 as amended in 2015:

1.  Cereals containing gluten, namely: wheat (including spelt and khorasan wheat), rye, barley, oats or their hybridised strains and derived products, except: 

(a) wheat-based glucose syrups, including dextrose;

(b) wheat-based maltodextrins;

(c) barley-based glucose syrups;

(d) cereals used for the manufacture of alcoholic distillates, including ethyl alcohol of agricultural origin.

2.   Crustaceans and products thereof.

3.   Eggs and egg products.

4.  Fish and fishery products except:

(a) fish gelatine used as a carrier for vitamin or carotenoid preparations;

(b) fish gelatine or fish glue used as a fining agent in beer and wine.

5.   Peanuts and products thereof.

6.   Soya and soya products, except:

(a) refined soybean oil and fat and derived products, in so far as the processing they have undergone is not likely to raise the level of allergenicity assessed by the Authority for the basic product from which they are derived.

(b) natural mixed tocopherols (E306), natural D-alpha tocopherol, natural D-alpha tocopherol acetate, natural D-alpha tocopherol succinate from soybean sources;

(c) vegetable oils derived from phytosterols and phytosterol esters based on soya;

(d) vegetable stanol ester produced from soy-based vegetable oil sterols.

7.   Milk and milk-based products (including lactose), except:

(a) whey used for the production of alcoholic distillates, including ethyl alcohol of agricultural origin;

(b) lactic acid.

8. Nuts, namely: almonds (Amygdalus communis L.), hazelnuts (Corylus avellana), walnuts (Juglans regia), cashew nuts (Anacardium occidentale), pecans [Carya illinoinensis (Wangenh.) K.  Koch], Brazil nuts (Bertholletia excelsa), pistachios (Pistacia vera), macadamia nuts or Queensland nuts (Macadamia ternifolia), and their products, except for nuts used for the manufacture of alcoholic distillates, including ethyl alcohol of agricultural origin.

9.   Celery and products thereof

10.  Mustard and products thereof.

11.  Sesame seeds and products thereof.

12.  Sulphur dioxide and sulphites in concentrations higher than 10 mg/kg or 10 mg/litre in terms of total SO2 to be calculated for the products as proposed ready for consumption or as reconstituted according to the manufacturers' instructions.

13.  Lupins and lupin products.

14.  Molluscs and products thereof

Allergens
(Management, labeling, control, and prevention in the food sector)

Description

• Food allergens are components (usually proteins or protein fragments) that can trigger an immune response—often IgE-mediated (immunoglobulin E; immediate-type allergy)—in sensitized individuals, with effects ranging from mild symptoms to potentially fatal anaphylaxis.
• They differ from intolerance (e.g., lactose due to lactase deficiency) and from autoimmune conditions such as celiac disease (gluten), which are not IgE-mediated but demand the same rigor in management.

Regulatory framework (EU, operational summary)

• Regulation (EU) 1169/2011: mandatory labeling and clear emphasis of allergens within the ingredient list; mandatory information also for non-prepacked foods (foodservice, loose sale).
• Annex II (EU list of 14 major allergens):

1. Cereals containing gluten (wheat, rye, barley, oats, spelt, kamut) and their products;

2. Crustaceans; 3) Eggs; 4) Fish; 5) Peanuts; 6) Soybeans; 7) Milk (including lactose); 8) Tree nuts (almonds, hazelnuts, walnuts, cashews, pecans, Brazil nuts, pistachios, macadamia/Queensland nuts);

3. Celery; 10) Mustard; 11) Sesame seeds; 12) Sulphur dioxide and sulphites >10 mg/kg or L as SO₂; 13) Lupin; 14) Molluscs.
   • Specific exemptions exist for some highly refined derivatives (e.g., certain wheat glucose syrups, highly refined soybean oil, fish gelatin as a vitamin carrier), where provided.
   • “Gluten-free”: < 20 mg/kg; “very low gluten”: 20–100 mg/kg.
   • PAL (Precautionary Allergen Labeling) such as “may contain …” should be used only after a documented risk assessment (e.g., VITAL approach with ED01/ED05 reference doses).

Allergy vs intolerance: key distinctions

• IgE-mediated allergy: rapid onset (minutes to hours), urticaria, angioedema, bronchospasm, anaphylaxis; emergency treatment with epinephrine.
• Non-IgE allergies (cell-mediated): delayed onset; gastrointestinal/dermatologic symptoms.
• Intolerances: non-immune mechanisms (e.g., enzyme deficits); often dose-dependent and with higher thresholds.
• Celiac disease: autoimmune reaction to gluten (gliadin peptides); managed via dietary exclusion and strict cross-contact control.

In-plant management (Allergen Management Plan)

• Mapping of allergens at site, line, recipe level and of personnel/material flows; risk assessment ingredient → process → product integrated into HACCP/GMP (first mention: HACCP = hazard analysis and critical control points; GMP = good manufacturing practices).
• Sourcing: supplier qualification, specifications with explicit allergen declaration, and control of derivatives (e.g., caseinates, whey proteins, soy lecithin, soy/wheat HVP, tahini).
• Design & segregation: dedicated storage, closed bins, color coding, dedicated tools, physical barriers where feasible.
• Production sequencing: schedule allergen-free first, with-allergen later; confine rework to the same allergen family.
• Sanitation & validation: validated cleaning procedures; verification via rapid protein or ELISA swabs; periodic re-validation and whenever changes occur.
• Training: staff awareness on identification, handling, hand/garment hygiene, and cross-contact prevention; control of PPE and flows.
• Documentation: integrated HACCP, CAPA, lot traceability, non-conformance handling and recall readiness.

Analytical methods (pros and cons)

• ELISA: allergen-specific proteins; excellent for cleaning verification; watch for matrix effects and denatured proteins.
• PCR: detects allergen DNA (useful for species ID); does not directly measure allergenic proteins.
• LC–MS/MS: targeted peptide markers; high specificity and multi-allergen capability; requires robust validation.
• Lateral flow (rapid tests): in-line screening; confirm with quantitative methods.
• Critical aspects: LOD/LOQ (limits), sample homogeneity, matrix effects, recovery, and reference materials.

Labeling

• Emphasize allergens within the ingredient list (bold, small caps, or color) consistently.
• Use ingredient names that clearly identify the allergen (e.g., “milk” rather than only “caseinate”).
• Apply PAL (“may contain …”) only if residual risk remains after all reasonable controls; define action levels (e.g., VITAL) and retain evidence.
• For foodservice and loose sale, ensure accessible information (allergen register, labels, digital menus).

Foodservice and retail

• Dedicated/prepared areas, separate utensils/tongs, glove changes between tasks, and fryer oil management (do not share oils to avoid transfer of gluten/fish/milk, etc.).
• “Free-from” preparations on freshly cleaned and sanitized surfaces; use covers and closed containers.
• Ongoing front-of-house training to capture customer information and communicate accurately with the kitchen.

Practical examples of “indicator” ingredients

• Milk: milk powder, whey, caseinates, lactose, clarified butter (ghee), dairy flavors.
• Egg: albumen/yolk, lecithovitellin, albumin, lysozyme (also as preservative).
• Soy: flour/tofu/tempeh, lecithin (E322), hydrolyzed vegetable protein (HVP), flavors.
• Gluten: semolina/flour, malt extract, breadcrumbs, thickened sauces.
• Tree nuts: pastes/creams/pralines, nut flours, gianduja, minimally refined nut oils.
• Sesame: tahini, bread/snack toppings.
• Sulphites: dried fruit, wine, vinegars, vegetable preserves.
• Fish: isinglass/fish gelatin (exempt in some uses), fermented fish sauces.

Consumer communication and health

• Allergic consumers must always read labels and ask in restaurants; carry their emergency plan and, if prescribed, an epinephrine auto-injector.
• “Free-from” products require rigorous cross-contact control and periodic analytical verification.
• Processing (cooking, fermentation) does not guarantee allergen inactivation; in some cases heat may increase allergenicity (e.g., roasted peanut).

Quality and specifications (typical contract topics)

• Absolute allergen disclosure for all ingredients and processing aids; analytical limits/targets for critical allergens.
• Validated cleaning plans and verification testing (rapid ELISA/total protein).
• Release criteria: approved label, claim coherence checks (e.g., “gluten-free”), production records and test results attached.
• Traceability for ingredients/packaging; tested withdrawal/recall plan.

Sustainability and supply chain

• Reduce waste by avoiding scrappage from mislabeling or accidental contamination (design for allergen control).
• Training lowers errors and recalls; optimized cleaning procedures and media cut BOD/COD (biochemical/chemical oxygen demand) in effluents.
• Efficient water/energy use and recyclable mono-material packaging support ESG goals.

Conclusion

Allergen management is a cross-functional process spanning formulation, procurement, production, sanitation, analysis, and labeling. A structured plan (HACCP extended to allergens), correct PAL usage, continuous training, and transparent consumer communication significantly reduce clinical risk and industrial risk (recalls and reputational damage).

Mini-glossary

• IgE — Immunoglobulin E; antibodies involved in immediate-type allergic reactions.
• PAL — Precautionary Allergen Labeling; statements like “may contain …,” used only after a documented risk assessment.
• VITAL — Voluntary Incidental Trace Allergen Labelling; scheme using ED01/ED05 (exposure doses eliciting reactions in 1%/5% of allergic population) to set action levels.
• ED01/ED05 — Reference doses for risk management (1%/5% of sensitive consumers); support PAL decision-making.
• HACCP/GMP — Hazard Analysis and Critical Control Points / Good Manufacturing Practices; food-safety systems that must explicitly cover allergen risks.
• LOD/LOQ — Limit of detection/limit of quantification; key analytical performance parameters.
• LC–MS/MS — Liquid chromatography–tandem mass spectrometry; targeted peptide method for multi-allergen detection.
• BOD/COD — Biochemical/Chemical Oxygen Demand; indicators of organic load in wastewater—important when optimizing cleaning systems.
• QUID — Quantitative Ingredient Declaration; percentage declaration of certain ingredients on labels.