AOAC Gluten Quantitative Validation Guidance-Round 1(Nov 2023)
301 302 303 304 305 306 Table 1. Rotation of gluten sources across claimed matrices for methods claiming to detect wheat, rye and barley. The rotation 307 of single gluten sources would continue for six matrices and greater. 308 309 310 311 312 313 314 315 316 317 318 Table 2. Rotation of gluten sources across claimed matrices for methods claiming to detect wheat, rye, barley and oats. The 319 rotation of single gluten sources would continue for six matrices and greater. 320 Alternatively, a matrix study for a matrix category may be performed by testing each claimed gluten source, per the rotation 321 shown in Table 1 or 2, in at least 5 examples from the category, equally distributed across each available type of processing 322 (Annex C). Test materials under each type of processing must be incurred. As an example, a method wishing to make a claim for 323 the “Cereals (Not Fermented, Hydrolyzed or Fractionated)” category would need to test one matrix from each of the five provided 324 processing categories, and in each instance, gluten would need to be added to the matrix prior to the described processing step. 325 If a method developer was unable to access suitable equipment for preparing incurred test materials in the Pressure/Extruded 326 type of processing, but was able to make incurred test materials for all other types of processing, they could not claim the “Cereals 327 (Not Fermented, Hydrolyzed or Fractionated)” category. However, they could make a limited claim for “Raw, Processed, Baked, 328 Fried and Dehydrated Cereals”. Method developers with the ability to produce fermented, hydrolyzed or fractionated matrix test 329 materials that were incurred with gluten prior to these processes may make individual claims based on the fermentation 330 organism, hydrolyzing agent or fractionation process. Example claims would be “Soy Tempeh fermented with Rhizopus 331 oligosporus ”, “Modified corn starch hydrolyzed with sodium hydroxide”, or “Wheat starch fractioned with water”. 332 Incurred test materials are required for evaluation of precision, LOD/LOQ, and recovery. See Annex B for description of best 333 practices for incurred test material preparation. 334 At least 4 concentrations per matrix/gluten source combination, including a zero/blank, must be included in the study. The 335 “Low” concentration should be less than or equal to two times the stated LOQ of the method, provided this is less than or equal 336 to 20 mg/kg (if not, then the “Low” concentration should be 20 mg/kg). Other concentrations should span the calibration range, 337 e.g., at the middle and upper end of the calibration curve. 340 recovery). Intermediate precision study designs must include multiple test portions, at least two test kit lots, and day/operator 341 as a single confounded factor. 342 Alternatively, a single, statistically valid study may be designed and utilized to provide estimates of precision (repeatability 343 and intermediate precision), LOD/LOQ, recovery, and lot-to-lot variability – see Figures 1-4 at the end of this document for 344 examples of acceptable study designs, but other designs may also be able to give satisfactory data. Designs 1b and 2b (Figures 2 345 and 4) will provide sufficient data for all parameters in the Matrix Study and the Product Consistency and Stability Study (5.2), if 346 Matrix B Wheat Wheat Wheat Wheat Matrix C Barley Barley Barley Matrix D Rye Rye Matrix E Wheat Number of Matrices Claimed 1 2 3 4 5 Matrix A Wheat Barley Rye Oats Wheat Barley Rye Oats Wheat Barley Rye Oats Wheat Barley Rye Oats Wheat Barley Rye Oats Matrix B Wheat Wheat Wheat Wheat Matrix C Barley Barley Barley Matrix D Rye Rye Matrix E Oats 338 339 Individual studies may be designed for each performance parameter (repeatability, intermediate precision, LOD/LOQ and
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