According to Japanese food allergen labeling regulation, the determination of allergenic food has been widely carried out independently in the food industry and by the governmental inspection agency. Among Morinaga FASPEK ELISA (Enzyme linked immunosorbent assay) kits determining allergenic foods, the wheat kit is observed a slight non-specific reaction with rice and corn. This non-specific reaction frequently creates the confusion in the ELISA result interpretation; whether wheat-free food, which frequently uses rice or corn, contains wheat. Due to this, a new wheat kit having no reactivity with rice and corn has been developed. The improved wheat kit was evaluated in 10 laboratories, using six types of model processed foods (chicken meatball, steamed fish paste, orange juice, custard pudding, baby food [Japanese-style mixed stew cooked in the retort pouch], and tomato sauce) containing 10μg wheat protein/g food. Mean recoveries in the model processed foods ranged from 92% to 130% in the improved ELISA kit. Relative standard deviations of repeatability and that of reproducibility were in the ranges of 6.2-10.9% and 10.2-16.2%, respectively. These results indicate that the improved wheat ELISA kit can be used as a more precise and reliable tool for determining wheat presence in processed food.
