AOAC RI ERP E-Book - DS DF

OMAMAN-38 B: Collaborative Study Protocol Expert Review Panel Use Only September, 2017

the Sugar-Pak ® column, a significant component in hydrolysed fructan, inulinotriose, is not measured as dietary fiber because it elutes at the same point as disaccharides.

Based on the HPLC chromatographic traces supplied by collaborating laboratories along with their results, it was evident that in some laboratories the HPLC systems were not being run optimally, as evidenced by a significant upward slant of the baseline of the chromatogram during a run. This indicates that the column is partially blocked and operating pressure is likely above the recommended level. Backwashing of the column over 24-48 h prior to its continued use will re-optimise the column performance. Collaborator Comments No negative comments were received concerning the method, but one collaborator did notice an allergic reaction to the PAA/AMG powder mixture. Therefore the protocol now includes an option where a non-allergic analyst can suspend the enzyme powder mixture in ammonium sulphate solution to produce a stabilized liquid form that reduces the risk to a susceptible analyst. One collaborator did not have access to the deionising pre-columns, so they deionised the samples according to the formats in AOAC Method 2001.03 (9). The same collaborator did not have a water bath that had orbital motion and was thus was advised to position the incubation containers at an approximately 45 o slant, parallel relative to the direction of shaking, to ensure that the sample did not settle to the bottom of the container during incubation. One collaborator asked for further advice on where to distinguish between SDFS and disaccharides on the HPLC pattern.

Acknowledgements The Study Director wishes to acknowledge and thank the following collaborators for all their efforts in completing this study: Nancy Ames, Agriculture and Agri-Food Canada/Agriculture et Agroalimentaires Canada, University of Manitoba – Winnipeg, Manitoba, Canada. Jodi Cox & Vincent McKie, Megazyme, Bray, County Wicklow, Ireland Delphine Curti & Sean Austin, Nestle, Food Science and Technology Carbohydrates, Nestlé Research Centre, Lausanne, Switzerland. Saskia Iilians and Monique Steegmans, CRDS Tienen, Central Department Research, Development and Services, Tienen, Belgium. Yulai Jin & Michelle Johnson, Kellogg Company, Battle Creek, MI, U.S.A. AOAC Research Institute ERP Use Only

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