Sharma Girdhari M
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Immunobiology Branch, Laurel, MD 20708, USA.
J AOAC Int. 2012 Mar-Apr;95(2):364-71. doi: 10.5740/jaoacint.sge_sharma.
Wheat proteins are responsible for sensitivities, including baker's asthma, immunoglobulin E (IgE)-mediated allergic reaction, wheat-dependent, exercise-induced anaphylaxis, and celiac disease. The detection of gluten/wheat traces in foods is important to safeguard the health of wheat-sensitive individuals and comply with food labeling. Many immunoanalytical-based commercial kits are available for the quantification of gliadin/gluten/wheat proteins. We compared the immunoreactivity of wheat fractions with wheat-allergic human serum IgE and antibody conjugates used in six commercial immunoassay kits. Moreover, the performance of the kits was tested using corn flour spiked with gluten (5, 10, 25, and 50 ppm) and wheat flour (50, 100, 250, and 500 ppm). The albumin, globulin, gliadin, and glutenin fractions reacted with IgE from nine, eight, two, and eight patients' sera, respectively, out of nine wheat allergic patients tested. Among the antibodies from commercial kits, those from R-Biopharm, Morinaga, and Romer Labs reacted strongly with the gliadin fraction, whereas those from BioKits, ALLER-TEK, and ELISA Systems reacted strongly with the glutenin fraction. All kits showed minimal or no reactivity with albumin and globulin fractions. All kits detected the gluten and wheat flour in a corn flour matrix at the lowest spiked levels of 5 and 50 ppm, respectively. However, there was wide variation among the kits when comparing the recovery of gluten and wheat flour. The recovery was also dependent on the source material (gluten or wheat flour) used for spiking the corn flour matrix.
小麦蛋白会引发多种过敏反应，包括面包师哮喘、免疫球蛋白E（IgE）介导的过敏反应、小麦依赖型运动诱发过敏反应以及乳糜泻。检测食品中的麸质/小麦痕量对于保障小麦敏感个体的健康以及符合食品标签规定至关重要。许多基于免疫分析的商业试剂盒可用于定量麦醇溶蛋白/麸质/小麦蛋白。我们比较了小麦组分与六种商业免疫分析试剂盒中使用的小麦过敏人血清IgE及抗体偶联物的免疫反应性。此外，使用添加了麸质（5、10、25和50 ppm）和小麦粉（50、100、250和500 ppm）的玉米粉对试剂盒性能进行了测试。在所检测的9名小麦过敏患者中，白蛋白、球蛋白、麦醇溶蛋白和麦谷蛋白组分分别与9名、8名、2名和8名患者血清中的IgE发生反应。在商业试剂盒的抗体中，R-Biopharm、Morinaga和Romer Labs的抗体与麦醇溶蛋白组分反应强烈，而BioKits、ALLER-TEK和ELISA Systems的抗体与麦谷蛋白组分反应强烈。所有试剂盒对白蛋白和球蛋白组分的反应极小或无反应。所有试剂盒分别在最低添加水平5和50 ppm时检测到玉米粉基质中的麸质和小麦粉。然而，在比较麸质和小麦粉的回收率时，各试剂盒之间存在很大差异。回收率还取决于用于添加到玉米粉基质中的原料（麸质或小麦粉）。
