AOAC Gluten Quantitative Validation Guidance-Round 1(Nov 2023)

GFA Gluten Quantitative Guidance Document Working Group Comments – Round 1 Resolution of each comment is provided in red text. The following comments were reviewed at the 2023 AOAC Annual Meeting:

Page 2, References: FDA ORA-LAB 5.4.5 (2020) Volume II —Methods, Method Verification and Validation, Document No IV-02 has been updated to (07/12/2023) you may put (2023). I see no difference in the updated chapter referenced other than the newest date of the most current version. Citation date was changed from 2020 to 2023 Page 3, Definitions 3.7 and 3.8: Change LOD to LOQ to stay consistent with page 4 4.3 cross-reactivity section, where cross reactivity is defined as above LOQ. LOD was changed to LOQ under both of these definitions Page 5, Section 4.1: Would like to see statement similar to the Gluten Qualitative document “Gluten has multiple potential sources… and perform validation for each claimed gluten source.” The following was added as the second paragraph under section 4.1 “Gluten has multiple potential sources – wheat, rye, barley, oats and their hybrids and crossbreeds – and multiple regulatory levels. Developers must determine which of these sources and levels their method is intended to detect, and perform matrix studies for each claimed gluten source.” Page 5, Section 4.3: What is the definition of selectivity (Selectivity not in definitions) and occurs ~15 times in the document and might have more than one intended usage. Selectivity is already included as definition 3.33 Page 5, Section 4.3, Breadth: Would like similar paragraphs from Gluten Qualitative document starting “The claimed gluten sources…” and “A method claiming wheat…” (Change qualitative language to more appropriate for quanititative.) Page 5, Section 4.3, Breadth: Delete "extrapolated", since extrapolation is not necessary for results above the LOQ. Page 5, Section 4.3, Breadth: Would like clarification on “calculate the mean recovery and 90% confidence interval for each (claimed) source.” This section has been re-written and now reads “This section of the validation is intended to provide information to end users on the method’s performance with less common varieties of gluten-containing grains, such as einkorn, spelt and emmer. The materials identified in Annex A, Table 1, should be tested at three times the LOQ of the method (as long as that is equal to or below 20 mg/kg, otherwise test at 20 mg/kg) in a rice flour matrix. Test six test portions per test material. The absorbance or optical density (OD) values for all test portions and standards must be reported. The mean gluten concentration for each gluten source must be reported. Mean concentrations below the LOQ