Determination of Gliadin as a Measure of Gluten in Food by R5 Sandwich ELISA RIDASCREEN® Gliadin Matrix Extension: Collaborative Study 2012.01.

BACKGROUND: According to Codex Alimentarius, food products containing less than 20 mg/kg gluten can be labeled as "gluten-free." Since 2002, the R5 antibody method allowed determination of gluten levels and led to a huge improvement of products available to celiac disease (CD) patients. METHOD: The R5-containing test kit RIDASCREEN® Gliadin in combination with the cocktail solution was endorsed as Codex Type 1 Method in 2006 based on a collaborative study with corn-based bread, rice-based dough, wheat starches, rice, and corn flour. In 2012, the method was approved as First Action Official MethodSM2012.01 with an "in foods" claim. For Final Action in 2016, the matrix claim was reduced to rice- and corn-based matrixes. OBJECTIVE: Therefore, R-Biopharm decided to start a collaborative study to demonstrate the wide applicability of Official Method 2012.01 for the quantitative analysis of gliadin in soy, starches, pseudo cereals, legumes, spices, juice, nut nougat crème, cream cheese, pesto, meat, vegetarian meat alternative, cookies, dessert, cake, fish, bread, candies, and potatoes. Materials for incurring were the MoniQA wheat flour and the PWG gliadin preparation. RESULTS: Gliadin levels ranged from 3.4 up to 27.4 mg gliadin per kg. The results of the collaborative study with 14 participating laboratories showed recoveries ranging from 80 to 130%. Relative reproducibility standard deviations for contaminated samples were between 9.8 and 27.7%. CONCLUSIONS: The collaborative study results confirmed that the method is accurate and suitable to measure gliadin in important gluten-free food matrixes. HIGHLIGHTS: The title and applicability statement of Official Method 2012.01 were changed as proposed.

Validation of the RIDASCREEN® Peanut for Determination of Peanut Protein in Cookies, Milk Chocolate, Ice Cream, Trail Mix, Puffed Rice Cereals, and Granola Bar: AOAC Performance Tested MethodSM 112102.

BACKGROUND: Regulations in many countries worldwide prescribe that peanut must be listed on food labels as a cause of food allergies. Re-evaluated voluntary incidental trace allergen labelling (VITAL) values for peanut revealed the eliciting dose (ED01) value-at which 99% of all peanut-allergic individuals will not react-is 0.2 mg peanut protein. OBJECTIVE: Validation of a sandwich ELISA based on monoclonal antibodies to detect peanut proteins. METHODS: Non-processed and processed samples are extracted by an easy procedure at 60°C within 10 min. The measurement range is between 0.75 and 6 mg/kg peanut using a national institute of standards and technology (NIST) reference material as calibrator. RESULTS: The system shows no cross-reactivity against 91 different food commodities. The LOD was 0.15 mg/kg for food matrixes such as cookies, milk chocolate, ice cream, trail mix, puffed rice cereal, and granola bar. LOQ was verified at a level of 0.75 mg/kg. Recovery studies with incurred milk chocolate and ice cream revealed consistent recoveries between 67 and 85%. Mean recoveries for incurred cookies depend on the baking temperature and time and ranged from 60 to 109%. Repeatability was between 5.2 and 12.3%, whereas relative intermediate precision was between 6.4 and 13.0%. The results for incurred cookies and milk chocolate in the independent laboratory study showed mean recoveries between 99 and 104% with RSDs between 3.56 and 19.5% under repeatability conditions. CONCLUSION: The results from the in-house validation study and the independent lab confirmed that the method is accurate and in accordance with requirements laid down in Standard Method Performance Requirement 2017.020. HIGHLIGHTS: RIDASCREEN® Peanut quantifies proteins from peanut in a wide range of food categories.