AOAC Gluten Qualitative Validation Guidance-FINAL (July 2023)

Gluten Public Comments (Responses)

Per WG discussion at the 2023 AOAC Midyear Meeting, this section will not be modified, but the CODEX footnote regarding oats will be added to the document along with the Gluten definition. ------------------------------------------------------------------------------------------------------------------------------------------ Definitions 3.2 and 3.28, “Biological Replicates” These 2 terms here, “Biological” vs “Technical” replicates are confusing, non-specific and apt to cause confusion and misunderstanding. You can use other, more specific terms to describe the procedures. This definition is inadequate. If you must use, I would suggest that the first sentence here is not a definition really. It should be: “Replication whereby multiple test portions are extracted and analyzed separately as individual, independent trials.” Rationale: AOAC should be using terms that utilize the recent advances in statistical sampling theory. The best resource for terms are the AAFCO Good Samples and Good Test Portions guidance documents. The terms “biological replicate” and “technical replicate” and the associated concepts are not used in the contemporary literature. Per WG discussion at the 2023 AOAC Midyear Meeting, these terms were deleted, and will be replaced with explanations when needed. “Biological replicate” has been replaced throughout with “test portion”. ------------------------------------------------------------------------------------------------------------------------------------------ Definition 3.5 (now 3.4) "Original Text in section 3.5: An analyte concentration, expre ssed in mg/kg of gluten (or μg per surface area), that demonstrates a Probability of Detection (POD) of at least 0.95. This may be claimed as one level that achieves a POD of 0.95 across all validated matrices, or individually per matrix. The claimed detection capability must be verified empirically during method validation. Proposed New Text: “An analyte concentration, expressed in mg/kg of gluten (or μg per surface area ), that demonstrates a Probability of Detection (POD) of at least 0.95. This may be claimed as one level that achieves a POD of 0.95 across all validated matrices, or individually per matrix. The claimed detection capability must be verified empirically during method validation. In the case that multiple gluten sources are claimed, a CDC shall be declared for each source.” Justification: Antibodies are unlikely to have equal response across gluten sources. CDC’s should be selected to best represent kit performance for each gluten source." Per WG discussion at the 2023 AOAC Midyear Meeting , definition was amended to read “An analyte concentration, expressed in mg/kg of gluten (or µ g per surface area), that demonstrates a Probability of Detection (POD) of at least 0.95. This may be claimed as one level that achieves a POD of 0.95 across all validated matrices, or individually per matrix and/or gluten source. The claimed detection capability must be verified empirically during method validation.” The final sentence that reads “In the case that multiple gluten sources are claimed, a CDC shall be declared for each source.” was added under 4.1.4, Data Analysis and Reporting for Matrix/POD Studies”. ------------------------------------------------------------------------------------------------------------------------------------------ Definition 3.7 (now 3.6)