AOAC GFA Stakeholder Program Meeting Book (March 15, 2023)

4.2.2 Matrix Study An independent laboratory, approved by AOAC or the appropriate agency, will perform a matrix / POD study for each gluten source in at least one incurred matrix per claimed matrix category, or in at least one matrix per every five individual matrices claimed Since we (absolutely justified) put a lot of emphasis on the necessity to test incurred matrices, at least one incurred matrix tested by the independent laboratory for PTM and at least one incurred matrix tested in the collab study should also be prepared by an independent entity (according to a recipe provided by the method developer). Note Section 4 states that “ Ideally, test materials for the independent laboratory and collaborative studies should be prepared by an external entity independent from the method developer. In situations where an independent entity is unavailable, method developers may produce and distribute test materials if detailed information is provided on procedures used to prevent bias (preparation, coding, etc .)”