AOAC 133rd Annual Meeting - Final Program

Scientific Sessions | Wednesday

CRM for infant formula and adult nutritionals at the request of industry, to provide a complementary matrix challenge. NIST is currently establishing partnerships with multiple manufacturers to provide additional reference materials that represent the wide variability of infant formula and adult nutritional products. SYMPOSIUM: Latest Developments in Gluten Analysis 10:15 AM – 11:45 AM Grand Ballroom 1 Chairs: Girdhari Sharma, U.S. Food and Drug Administration Carmen Diaz-Amigo, FOCOS Food Consulting Strategically 10:15 AM Validation of an ELISA for Total Gluten Determination Thomas Weiss, Markus Lacorn , R-Biopharm AG, Katharina Scherf, Technical University of Munich The R5 method to quantify gluten led to a strong improvement of the situation for the food industry and celiac patients. However, during the last years some questions arose related to the anal- ysis of oats, which led to the development of AOAC SMPR ® 2017.021. Here we present a method for the quantitative analysis of wheat, rye, and barley gluten in oat and oat products, using a sandwich ELISA based on four different monoclonal antibodies including the R5 antibody. The ELISA detects intact gliadins and related prolamins from rye and barley, high-molecular weight (HMW) glutenin-subunits (GS) from wheat, HMW-secalins from rye and low-molecular-weight (LMW)–GS from wheat. In-house validation of the method showed an LOD of 4 mg/kg gluten and an LOQ of 5 mg/kg gluten. AOAC reference mate- rials (SMPR ® 2017.021) showed recoveries between 86% and 131% for wheat and barley, while rye showed higher recoveries between 137% and 170%. Recoveries studies with incurred oat cookies and porridge revealed values between 55% and 122%. An AOAC collaborative study with 19 laboratories showed recoveries ranging from 99% to 137% for all three grains and good reproducibility. The AOAC granted the status of an Official Method of Analysis ™. 10:35 AM An Update on Gluten Analysis by LC-MS/MS Michelle Colgrave, CSIRO Agriculture and Food Consumers, especially those with allergies and/or intolerances, should have confidence in two critical areas of food safety: foods should be correctly labelled and free from contamina- tion. Coeliac disease is a condition that affects 1-2% of the population, while non-coeliac wheat sensitivity may affect up to a further 10% of the population. There is no current treat- ment for either of these conditions other than strict adherence to a life-long gluten-free diet. The industry standard for gluten measurement involve the use of antibody-based techniques including ELISA. In recent years, LC-MS/MS approaches have

been developed as an alternative method of gluten analysis. This can be advantageous when examining heavily processed food products wherein modifications to the protein sequence and/or structure may affect the antibody-antigen interaction. LC-MS/ MS typically relies on the digestion of proteins to yield peptide markers. Using these peptide markers LC-MS/MS is used to detect the presence/absence of gluten and quantify the levels of gluten across the diverse range of food matrices that exist. More recently, novel approaches employing untargeted LC-MS/ MS have been explored as a means to detect gluten without a priori knowledge of the target proteins. In this presentation, the current status, knowledge gaps and future opportunities will be discussed. 10:55 AM Appropriate Sampling Can Help Improve Decision Making in Gluten-Free Systems Paul Wehling, Medallion Laboratories / General Mills Gluten-free foods sold in the US, Canada, and EU are required by regulations to contain less than 20 mg/kg gluten. For food producers managing a gluten-free supply chain, sampling, and testing at various stages of production is a common practice. When designing such testing systems, various factors need to be decided upon, such as how frequently to sample, lot size, and testing replication. In order to optimize the testing plan, certain characteristics of the manufacturing process need to be known, primarily the inherent variation in the process system, sampling variance, and the analytical variance of the test method. Once these factors are estimated, various sampling schemes can be developed and compared by construction of an operating characteristic (OC) curve for each proposed plan. This presenta- tion will discuss these topics and show examples of appropriate sampling schemes for various theoretical systems and compare proposed plans by analysis of simulated OC curves. 11:15 AM Impact of Extraction Conditions and Food Matrix on Gluten Testing Laura Allred, Gluten Free Certification Organization Antibody-based gluten testing methods with a part-per-million quantitation range have been available for nearly 30 years, with the first AOAC OMA for gluten issued in 1991. These tests have been invaluable for regulators and the gluten-free community, but since their inception the expected recovery values have had a wide range, typically 50-150%. The sample matrix, extraction methods, antibody specificity, and the analyte itself all contrib- ute to the need for this wide recovery allowance. Very few food matrices have been analyzed in the AOAC OMA and PTM methods for gluten, and some common food matrices are not appropriate for use in any of the validated methods, so there is a lot for the end-user to consider when determining which method, if any, is the best fit for their purpose.

24 SEPTEMBER 6–12, 2019 SHERATON DENVER DOWNTOWN HOTEL