Food allergies affect 1–2 percent of the UK population, in some cases causing severe reactions such as anaphylaxis, according to the UK Food Standards Agency (FSA). Under the UK Food Information Regulation (FIR), food businesses are legally required to provide accurate and understandable allergen information for 14 priority allergens (i.e., celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, mollusks, mustard, peanuts, sesame, soybeans, sulphur dioxide and sulphites, and tree nuts). This includes declaring the presence of allergens as ingredients and warning consumers about potential cross-contact risks.

In support of food allergen safety, FSA commissioned a review to assess the current state of allergen testing methodologies, with the goal of identifying gaps, harmonizing testing protocols, and supporting risk management strategies. The project combined a critical literature review, analysis of proficiency testing data, and consultations with industry stakeholders and experts. The work was conducted by Fera Science Ltd.

The findings of this review were recently presented in an online seminar hosted by LCG Ltd. and by the UK Joint Knowledge Transfer Framework; an initiative which is funded by FSA, Food Standards Scotland (FSS), and other UK Government departments to advance food safety, hygiene, and standards. The seminar can be watched on YouTube.

Current Allergen Testing Methods and Limitations

Per the review, the most widely used method, Enzyme-Linked Immunosorbent Assay (ELISA), detects allergenic proteins using antibodies. Monoclonal antibodies offer specificity, reducing cross-reactivity, while polyclonal antibodies increase detection in processed foods but may yield false positives. Performance varies significantly across ELISA kits, with some failing to specify target proteins or validation matrices. For instance, ovalbumin in eggs becomes undetectable after thermal processing, whereas ovalmucoid remains stable—underscoring the importance of knowing the targeted protein of each kit.

Polymerase Chain Reaction (PCR) is used as a confirmatory method, amplifying DNA to infer allergen presence. While PCR cannot detect proteins directly, it performs well with some processed foods where ELISA may fall short. However, its applicability is limited for allergens lacking distinguishable DNA.

Mass spectrometry (MS) is emerging as a promising technique, offering high specificity by identifying unique peptide sequences. It has demonstrated success in detecting allergens like peanuts and mustard at very low levels. Still, MS methods require further refinement to match ELISA’s sensitivity and broader validation across food types.

Emerging Risks and Innovation Challenges

The rise of alternative proteins presents new challenges for allergen management. Novel sources, including insect proteins and highly processed plant-based ingredients, may introduce allergens to populations with no prior exposure. For example, tropomyosin in cockroaches is structurally similar to crustacean allergens, posing risks to crustacean-allergic consumers. Similarly, processing methods can alter the allergenicity of familiar plant proteins like soya and pea, potentially increasing allergic reactions.

Pea protein, a key ingredient in many alternative products, has shown allergenic potential, though not yet at levels warranting regulatory declaration. Proactive development of testing methods for pea protein is essential before its prevalence increases.

To mitigate risks, innovators—often small enterprises—must be educated on allergenicity and equipped with testing strategies. Historical missteps, such as an instance in which a transgenic soybean contained a Brazil-nut allergen, highlight the importance of thorough risk assessment.

Recommendations and Future Directions

The review calls for:

• Development and funding of rapid, multi-allergen point-of-use tests to reduce cross-contamination risks
• Improvement of multiplex mass spectrometry methods for rapid, confirmatory testing
• Validation of methods across diverse food matrices
• Creation of open-access databases detailing cross-reactivity and kit performance
• Establishment of industry-wide standards for testing thresholds and procedures
• Reliable, independent auditing of global suppliers in the UK supply chain.

As the food industry evolves, robust allergen detection and risk management strategies are critical to safeguarding consumers and supporting innovation.