AOACRIGlutenMethods-2017Awards

H albmayr -J ech et al .: J ournal of AOAC I nternational V ol . 98, N o . 1, 2015  111

Martin Hemingway, ALcontrol Laboratories, Rotherham, United Kingdom Rupert Hochegger, Austrian Agency for Health and Food Safety, Vienna, Austria Jennifer Jolly, Covance Laboratories Inc., Battle Creek, MI Prabhakar Kasturi, Pepsico Inc., Barrington, IL Peter Koehler, Deutsche Forschungsanstalt für Lebensmittelchemie, Freising, Germany Christine Poirier and Terry Koerner, Health Canada, Ottawa, Canada Adrian Rogers, Romer Labs UK Ltd, Runcorn, United Kingdom Girdhari Sharma, U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Laurel, MD Robin Sherlock, Food Allergen Control Training Analysis, Tennyson, Australia Carolina Sousa, Universidad de Sevilla, Spain Steve Taylor, Food Allergy Research and Resource Program, University of Nebraska–Lincoln, Lincoln, NE Joanna Topping, LGC Ltd, Teddington, United Kingdom Paul Wehling, General Mills, Inc., Minneapolis, MN Michael Marquard, Medallion Labs, Minneapolis, MN  (1) Morón, B., Bethune, M.T., Comino, I., Manyani, H., Ferragud, M., López, M.C., Cebolla, A., Khosla, C., & Sousa C. (2008) PLoS ONE 3 (5), e2294. http://dx.doi.org/10.1371/journal. pone.0002294  (2) Morón, B., Cebolla, A., Manyani, H., Alvarez-Maqueda, M., Megías, M., Thomas M.C., López, M.C., & Sousa, C. (2008) Am. J. Clin. Nutr. 87 , 405–414  (3) Halbmayr-Jech, E., Hammer, E., Fielder, R., Coutts, J., Rogers, A., & Cornish, M. (2012) J. AOAC Int. 95 , 372–376. http://dx.doi. org/10.5740/jaoacint.SGE_Halbmayr-Jech  (4) Codex Standard for Foods for Special Dietary Use for Persons Intolerant to Gluten-Codex STAN 118–1979 (2008) Codex Alimentarius Commission, Rome, Italy  (5) Wieser, H., Antes, S., & Seilmeier, W. (1998) Cereal Chem. 75 , 644–650. http://dx.doi.org/10.1094/CCHEM.1998.75.5.644  (6) van Eckert, R., Berghofer, E., Ciclitira, P.J., Chirdo, F., Denery- Papini, S., Ellis, H.J., Ferranti, P., Goodwin, P., Immer, U., Mamone, G., Mendez, E., Mothes, T., Novalin, S., Osman, A., Rumbo, M., Stern, M., Thorell, L., Whim, A., &Wieser, H. (2006) J. Cereal Sci . 43 , 331–341. http://dx.doi.org/10.1016/j. jcs.2005.12.009  (7) Koehler, P., Schwalb, T., Immer, U., Lacorn, M., Wehling, P., & Don, C. (2013) Cereal Foods World 58 , 36–40. http://dx.doi. org/10.1094/CFW-58-1-0036  (8) Koehler, P., Schwalb, T., Immer, U., Lacorn, M., Wehling, P., & Don, C. (2013) Cereal Foods World 58 , 154–158. http://dx.doi. org/10.1094/CFW-58-3-0402  (9)  Official Methods of Analysis (2002) Guideline for Collaborative Study Procedures to Validate Characteristics of a Method of Analysis, AOAC INTERNATIONAL, Rockville, MD, Appendix D (10) Abbott, M., Hayward, S., Ross, W., Godefroy, S.B., Ulberth, F., van Hengel, A.J., Roberts, J., Akiyama, H., Popping, B., Yeung, J.M., Wehling, P., Taylor, S.L., Poms, R.E., & Delahaut, P. (2010) J. AOAC Int. 93 , 442–450 (11) Thompson, M. (2000) Analyst 125 , 385–386. http://dx.doi. org/10.1039/b000282h References

Figure 2. Plot of reproducibility SD (S R ) versus the global mean observed gluten concentration for the interlaboratory study.

and strongly increased the viscosity of the extract. Hence, a clear separation of extract aliquots was more difficult with this matrix. This may also explain the higher CV in the homogeneity tests. Due to the complexity of the cake recipe we cannot pinpoint a single reason for low recovery, but a combination of the factors mentioned is most likely. Taking this complexity into account, the method evaluated here largely complies with the guidelines and best practices for allergen ELISA methods (10). With an LOD of 4.3 mg gluten/kg, it fulfills the LOD requirement of ≤10 mg/kg of Codex Alimentarius (4). This collaborative study has shown that the G12 Sandwich ELISA is capable of quantifying gluten in foods with an LOD of 4.3 mg gluten/kg. This method shows good precision and accuracy in the concentration range of most interest (20 mg/kg and above), where it has to be decided whether a sample meets guidelines for gluten content. Some matrix effects, especially with the incurred chocolate cake samples, may lower recovery as compared to spiked samples. Therefore, it may be beneficial to occasionally check recovery by using internal reference samples with known gluten content. According to these results, it is recommended that the method be accepted by AOAC as Official First Action . Conclusions and Recommendation We thank Peter Köhler and Katharina Schiesser for preparing the samples and Paul Wehling and Terry Nelsen for useful discussions on statistics. Furthermore, we thank the following collaborators for their participation in this study: Guenther Augustin, Dr. Schär S.r.l, Postal, Italy Christy Brewe, Romer Labs, Inc., Union, MO Zsuzsanna Bugyi and Sandor Tomoszi, Budapest University of Technology and Economics, Hungary Dean Clarke, National Measurement Institute, Port Melbourne, Australia Peter Cressey, Institute of Environmental Science and Research Ltd, Christchurch, New Zealand Andreas Firzinger, Romer Labs Diagnostic GmbH, Tulln, Austria Janette Gelroth, AIB International, Manhattan, KS Acknowledgments