From Matrix to Protein: The Evolving Approach to Allergen Quantification in Food

Effective allergen management is paramount in food safety programs. It is estimated that approximately 2-5% of adults and 4-10% of children worldwide are affected by food allergies today, highlighting the critical importance of accurate allergen control. Traditionally, allergen residues were quantified using the allergenic matrix (e.g., “ppm peanut,” “ppm milk”). However, global best practices and programs such as VITAL (Voluntary Incidental Trace Allergen Labeling), are driving a significant shift toward reporting results in terms of allergen protein (e.g., “ppm peanut protein”). This shift reflects a deeper understanding of allergenicity and enhances consumer protection. This article explores the rationale behind this change, its advantages, and how food safety professionals, quality, and production managers in the food industry can adapt to this evolving paradigm.

 

The Limitations of Matrix-Based Allergen Quantification

Historically, allergen testing methods have reported results as the concentration of the source material—such as “almond” or “milk”—found in a product. For example, an ELISA test might provide a result in “ppm almond” by comparing the sample’s reaction to that of a known ground-almond standard (i.e. the whole commodity). However, this approach has significant shortcomings:

• Indirect Allergen Assessment: Allergic reactions are triggered by specific proteins. Expressing results as “ppm milk” obscures the actual quantity of allergenic proteins responsible for these reactions. For example, milk's major allergens are casein and whey proteins, and their ratios vary. Therefore “ppm milk” fails to specify these critical protein levels.
• Variable Protein Content: The protein content within a matrix (e.g., almond) can vary substantially due to factors like cultivar, growing conditions, processing (roasting, blanching, defatting), and geographical origin. For instance, roasting can denature proteins, affecting detectability and potentially allergenicity. Almond protein content can fluctuate by 20-30% based on these variables.
• Comparability Challenges: Diverse raw material sources and processing conditions hinder direct comparisons of “ppm almond” results across products and facilities, complicating the establishment of consistent safety thresholds and accurate risk assessments.

 

The Shift to Protein-Based Results and the Role of VITAL

The VITAL program, managed by the Allergen Bureau, is an internationally recognized framework for allergen risk assessment and labelling. A key recommendation of VITAL is shifting from matrix-based to protein-based reporting—an approach that acknowledges that allergenic reactions are initiated by specific proteins rather than the total mass of the allergenic food. By directly measuring allergenic proteins, VITAL ensures a more precise representation of consumer risk.

VITAL provides protein-based action levels, aiding food businesses in making informed decisions about precautionary allergen labelling (PAL). Its reference doses are grounded in clinical data on the protein levels that can trigger allergic responses. While not a regulatory mandate, VITAL is a widely adopted industry best practice thanks to its scientific rigor and alignment with emerging global standards.

In parallel, organizations such as the Codex Alimentarius Commission (Codex) and the European Committee for Standardization (CEN) play pivotal roles in shaping allergen standards. Codex sets international food standards and guidance on allergen labelling; although it does not explicitly mandate protein-based quantification, its endorsed testing methods typically measure immunologically reactive proteins. CEN develops European standards - including analytical methods and protocols - that often focus on protein-based detection, thus influencing regulatory frameworks across EU Member States.

Together with VITAL, these organizations contribute to the growing global consensus that quantifying allergenic proteins—rather than total food matrix mass—is the most accurate way to protect allergic consumers and ensure clear, consistent allergen labelling worldwide.

 

Why “ppm Protein” is More Meaningful for Allergen Quantification?

• Direct Link to Allergenicity: Proteins are the immunologically active components. Expressing results in terms of protein focuses on the fraction that actually causes allergic reactions, ensuring that safety thresholds are directly tied to the risk at hand.
• Consistency Across Formats: The protein content of the allergen can remain consistent - even when the raw commodity form might differ. Whether an ingredient is in powder, paste, or other processed states, focusing on the protein fraction offers a standardized measurement.
• Enhanced Risk Assessment: Setting action levels and risk thresholds based on allergenic protein aligns better with how the body reacts. This alignment leads to more accurate labelling decisions and better consumer protection. Furthermore, it allows for more accurate risk assessments for foods that are highly processed, or that contain many different ingredients.
• Clarity in Communication: When referencing “ppm milk protein” for instance, you eliminate confusion about whether the result refers to whole milk, skim milk, milk powder, or other derivatives. This clarity helps regulatory bodies, production managers, and, ultimately, consumers.

 

Operational and Regulatory Implications

Changes in Testing and Validation

• Method Selection: Laboratories and in-house testing facilities may need to adopt or validate new methods that quantify proteins specifically (e.g., allergen-specific ELISAs)
• Reference Materials: Laboratories will require standard reference materials designed to express allergen content in terms of protein. This includes calibrating test methods against purified protein standards and using proficiency testing providers that create materials expressing the assigned value in parts per million (ppm) of protein. This will definitively lead to a more harmonized consensus regarding the proficiency testing results.
• Training and Competency: Quality teams and lab analysts must be trained to understand the distinction between matrix-based and protein-based results and interpret the latter in the context of regulatory or customer requirements.

Allergen Risk Management and Labeling

• Thresholds and Action Levels: Many global markets are exploring or adopting protein-based thresholds (e.g., mg of allergen protein per kg of food). Food businesses should monitor these regulatory developments and adjust their processes accordingly.
• Allergen Control Programs: Verification steps - such as cleaning validation or production line swabbing - will become more precise when measured against protein-level action points. This could enhance the overall allergen management system.

Communication with Stakeholders

• Cross-Department Collaboration: Production managers and quality managers must work closely to ensure allergen cross-contact is controlled to protein-based levels.
• Consumer Safety and Transparency: Marketing and labelling teams benefit from clearer, science-based explanations of trace allergen statements, building consumer trust.
• Regulator and Customer Expectations: When protein-based reporting becomes the norm, demonstrating compliance will require transparent documentation of detection methods, validation data, and ongoing verification results.

 

Conclusion

The move from “ppm matrix” to “ppm protein” is a major milestone in allergen management - providing greater accuracy, improved risk assessment, and enhanced consumer safety. Driven by programs like VITAL and backed by evolving detection technologies, this shift reflects a deeper scientific understanding of what truly causes allergic reactions. By focusing on protein - the immunologically relevant component - food manufacturers and regulators can establish more reliable thresholds, enable more consistent test methods, and ultimately protect allergic consumers with greater precision.

For food safety professionals, quality managers, and production managers, the transition may require some initial adjustments to testing protocols and documentation. However, the long-term benefits in accuracy, regulatory compliance, and consumer trust make “ppm protein” the clear path forward in allergen risk management.