Validation of the BioSystems Gluten Immunoturbidimetric Method for Determination of Gluten in Selected Food and Beverage Matrixes: AOAC Performance Tested Method SM 072503

BACKGROUND: The BioSystems Gluten is an automated quantitative method based on immunoturbidimetry for quantification of the 33-mer peptidic immunotoxic fraction of gluten in food and beverages, crucial for ensuring safety for those with gluten-related disorders like celiac disease (CD). OBJECTIVE: An AOAC Performance Tested MethodSM validation study was performed to evaluate the BioSystems Gluten method for the quantification of gluten from wheat, barley, and rye flours across selected food and beverage commodities, including both non-processed and processed products. METHODS: Validation covered non-processed (rice flour, corn flour, wine, and sausage) and incurred matrixes (cornbread and rice cookies), spiked with wheat, barley, and rye gluten (0-30 mg/kg). Twelve test portions were analyzed for each matrix and contamination level using three different kit lots. The study evaluated linearity, bias, recovery, precision, LOD and LOQ, selectivity, and interferences, evaluated by recovering gluten in a defined gluten-free matrix group, stability studies of the kit components, and method robustness following AOAC Guidelines for Quantitative Gluten Methods. RESULTS: The method met AOAC performance requirements for the quantitative determination of gluten from wheat, barley, and rye across a variety of representative food commodities and spiking levels. The validated working range spans the LOQ (2.5 mg/kg) to 200 mg/kg. The method achieved satisfactory recovery rates within the established acceptance limits, showed no evidence of analytical interferences, and yielded comparable results between the method developer and an independent laboratory, supporting its robustness and reproducibility. CONCLUSION: The validation study conclusively establishes the test kit as an automated, precise, rapid, and user-friendly method for quantifying gluten concentrations in both food and incurred matrixes derived from wheat, barley, and rye flours. HIGHLIGHTS: A novel automated method is presented for gluten quantification based on spectrophotometric analysis in a Biosystems Y15 analyzer with ready-to-use and liquid reagents.