Allergen Detection Methods - The Compendium of Food Allergen Methodologies

On this page:

• Background
• Evaluation Guidelines
• List of Food Allergen Methodologies
• Allergen Methods Committee

Background

With the emergence of several allergen detection methodologies, there was a need to adopt a consistent approach to evaluate/validate these methods, if they are to be used in enforcement/compliance activities. The reporting of results for the presence of allergen markers in investigated food commodities is dictated by risk assessment needs. According to Health Canada 's existing procedures, these results are to be quantitative and are to be expressed in concentration of proteins (i.e. µg of protein per gram of commodity). Considering these prerequisites, it is important to qualify the calibrators or standard solutions used in these protein-based methodologies in terms of their "protein content". Despite the inconsistencies that may be encountered with protein determination methods, the Allergen Methods Committee (AMC) has has agreed to estimate the protein content of standards or calibrators using a standardized protein assay: the Bicinchoninic Acid Assay (BCA test) with Bovine Serum Albumin (BSA) as a reference. Although subject to discussion, considering the variation in nature and behaviour of soluble allergen proteins in comparison to BSA, it was agreed to use a common reference for reporting purposes. These reference parameters are reported along with the assay results, if used as part of an investigation.

Another challenge faced in the development of the Compendium of Methodologies is to achieve an evaluation process that meets the requirements of various methodology users, without necessarily imposing a threshold value to be fulfilled by methods. It remains to users to decide on the suitability of existing / evaluated methods, according to their own needs. Nonetheless, it was important to establish a homogeneous protocol of evaluation where possible, by designating one or several reference materials which can be utilized in fortification experiments (naturally-incurred or artificial fortification) for the food matrices of interest. The AMC has defined a reference material as a "material that is representative of the allergenic food commodity, that is well characterized and that can be produced/supplied with reproducible characteristics".

Evaluation Guidelines

The AMC has set general criteria for the introduction of allergen analytical methods into the compendium. The general principles behind this set of criteria are:

• The Compendium of Methodologies aims at reporting the performance of methods that were evaluated according to an agreed-upon experimental protocol. Inclusion in the compendium does not imply endorsement or approval of specific methods.
• The evaluation protocol will be designed and implemented in total collaboration with the method developer, whether a test kit manufacturer or a private, university or government laboratory, and will be tailored according to the specificities of each allergen studied and the corresponding reference materials developed.
• Two levels of evaluation will be targeted:
  1. an entry level, where a method is experimentally evaluated by a single AMC-affiliated laboratory (designated labs from HC & CFIA) and that of the method developer, and
  2. a full evaluation level, where results are generated by at least three AMC-affiliated laboratories and that of the method developer/author.
• A designated reference material should be defined for the method to be evaluated and must be of some validity of use for more than the targeted test kit, allowing therefore an evaluation of the performance of several comparable test kits/methods.
• Levels of fortification and matrices to be targeted will be defined according to the claims of the method author: typically, 3 levels of fortification will be evaluated, a blank, 2xLOQ(limit of quantification) and 5xLOQ.
• The number of replicates has been defined so that the evaluation / validation process does not impact negatively on activities of the participating laboratories, whose primary mission is to deliver on compliance activities rather than to be involved in laborious evaluation of methodologies.
• The report of performance on evaluated methods will be posted on a web-based version of the allergen Compendium of Methodologies which will make available more data on existing methodologies and allow users from the analytical community to choose methods according to their needs.
• The generated data will be shared in agreement with all involved parties, including the method developer/author and will enable a better understanding of data provided by a third party using one of these evaluated methods.
• Federal laboratories are free to use whatever testing methodologies they consider appropriate to fulfill the requirements of their allergen testing. Such information will not be posted on the web-based application, as it is subject to change and may be regarded as an endorsement of a particular method.
• The Compendium of Methodologies will also incorporate reports of performance on allergen methods that were evaluated / validated under the auspices of other institutions such as the AOAC International, or following protocols established by other sister organisations, once approved by the AMC. The appropriate approval requests will be sought from various parties involved (test developers, laboratories involved in validation), prior to making the data available in the compendium.

Allergen Methods Committee

Health Canada and CFIA recognized the need for a forum of open discussion among food laboratories involved in allergen testing and jointly established the Allergen Methods Committee (AMC). The AMC aims at providing direction and better coordination in the development, delivery and advancement of allergen testing and allergen research programs

Among the AMC's objectives:

• To provide scientific advice to the CFIA Programs with respect to methodology and delivery of allergen testing
• To coordinate research activities between government agencies involved in allergen research and method development
• To provide Health Canada's Food Allergen Research Program with pertinent information on priority setting and allergen research needs

The AMC is currently assisting in the coordination of inter-laboratory evaluation of both commercially available and in-house allergen detection methods. The aim is to develop and publish a compendium of evaluated allergen methodologies, which may be used for testing by industry and government laboratories. The AMC has therefore taken the responsibility of developing formalized guidelines and performance criteria for allergen methods as well as the development of designated reference materials and standards that will be used as a common ground for method evaluation and implementation in Health Canada and CFIA laboratories. The AMC contributes in international efforts of method harmonization/standardization as well the development and characterization of allergen reference materials.