Schall Eszter, Scherf Katharina A, Bugyi Zsuzsanna, Török Kitti, Koehler Peter, Schoenlechner Regine, Tömösközi Sándor
Research Group of Cereal Science and Food Quality, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary.
Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany.
Front Plant Sci. 2020 Jul 7;11:906. doi: 10.3389/fpls.2020.00906. eCollection 2020.
Celiac disease is a gluten-induced hypersensitivity reaction that requires a lifelong gluten-free diet. Gluten-free foods must not contain more than 20 mg/kg gluten as laid down by Codex Alimentarius. Measuring the presence of gluten with routine immunoanalytical methods in food is a serious challenge as many factors affect accurate determination. Comparability of the results obtained with different methods and method validation are hindered by the lack of a widely accepted reference material (RM). The core questions of RM development from wheat are the number of cultivars to be included and the format of gluten (i.e., flour, gluten, or gliadin isolates) to be applied. Therefore, the aim of our work was to produce an appropriate gluten RM from wheat. For this, five previously selected wheat cultivars and their blend were used to produce flours, gluten and gliadin isolates under laboratory conditions. Protein content, protein composition and responses to different ELISA methods were compared and widely evaluated in our study. The protein contents of the flours were 12.1-18.7%, those of the gluten isolates 93.8-97.4% and those of the gliadin isolates 72.7-101.9%. The gluten and gliadin isolates had similar protein profiles as the source flours. By comparing the different wheat cultivars and their protein isolates, we found that the isolation had a smaller effect on protein composition than genetic variability. The choice of a blend would be more suitable for the production of a RM in case of flours and also isolates. The immunoanalytical results showed that the isolation had an effect on the analytical results, but its extent depended on the ELISA method. The use of flour would be more applicable in this regard, but handling of the material and long-term stability should also be considered in the final decision of gluten RM production.
乳糜泻是一种由麸质引起的超敏反应，需要终身食用无麸质饮食。根据食品法典委员会的规定，无麸质食品中麸质的含量不得超过20毫克/千克。由于许多因素会影响准确测定，因此用常规免疫分析方法检测食品中麸质的存在是一项严峻的挑战。缺乏广泛认可的参考物质（RM）阻碍了不同方法所得结果的可比性以及方法验证。从小麦开发参考物质的核心问题包括要纳入的品种数量以及要使用的麸质形式（即面粉、麸质或麦醇溶蛋白分离物）。因此，我们工作的目的是从小麦中制备合适的麸质参考物质。为此，在实验室条件下，使用五个先前选定的小麦品种及其混合物来生产面粉、麸质和麦醇溶蛋白分离物。在我们的研究中，对蛋白质含量、蛋白质组成以及对不同酶联免疫吸附测定（ELISA）方法的反应进行了比较并进行了广泛评估。面粉的蛋白质含量为12.1 - 18.7%，麸质分离物的蛋白质含量为93.8 - 97.4%，麦醇溶蛋白分离物的蛋白质含量为72.7 - 101.9%。麸质和麦醇溶蛋白分离物的蛋白质谱与原料面粉相似。通过比较不同的小麦品种及其蛋白质分离物，我们发现分离对蛋白质组成的影响小于遗传变异性。对于面粉和分离物而言，选择混合物更适合用于生产参考物质。免疫分析结果表明，分离对分析结果有影响，但其程度取决于ELISA方法。在这方面，使用面粉更适用，但在最终决定麸质参考物质的生产时，也应考虑材料的处理和长期稳定性。
