AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

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nutritional products were received in 4 boxes, each containing 6 packs of 4 bottles (96 bottles). 1 From each box, one bottle was randomly selected, as well as two additional bottles among the 4 2 boxes and analysed in duplicate for their fructan contents ( n =6 ). Statistical analysis was performed 3 using the Cochran test according to the ISO 5725-2:1994 norm. The between sample variability 4 was demonstrated to be zero for the three products (data not shown). On this basis, the samples 5 were confirmed to be homogeneous for their fructan contents thus fit for purpose to be included in 6 the collaborative study. 7 The kits of samples were shipped at ambient temperature. The participants were asked to keep 8 the samples at room temperature before undertaking analysis and once opened, to keep them in 9 tightly closed containers for the duration of the study. The liquid products had to be kept at 4 °C 10 once opened. 11 All powdered samples were required to be analysed on a reconstituted basis, using 25 g of 12 material and 200 g of water, with the exception of the Standard Reference Material (SRM 1869) 13 which had to be reconstituted by dissolving 10 g of powder in 90 g of water. The liquid samples 14 were analysed “as is”. For most of the samples, no additional dilution was needed. However, for 15 some samples a dilution factor of 10 had to be applied. A table summarizing the reconstitution rates 16 and dilution factors to be applied was included in the MLT protocol received by the participating 17 laboratories and can be found in Table 1 . 18 A practice sample was also included in the kit. The participating laboratories were asked to 19 analyse the practice sample in duplicate and to record and report any deviation from the method 20 described in the protocol. The final result in g/100 g reconstituted product as well as sample 21 weights, dilutions, peak areas of standards and sample extracts, glucose and fructose concentrations 22 in the sample extracts and blank measurements, were communicated to the study director by filling 23 the reporting template provided with the protocol. Information on the analytical column and 24 instrument type used as well as brand of the graphitized carbon column and use or not of Carrez 25

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