A sensitive sandwich enzyme-linked immunosorbent assay (sELISA) targeted multiple wheat protein fractions for the detection of several cereal grains in processed foods.

Abstract

Wheat allergy has become a global public health and food safety concern; however, there is no accessible cure for wheat allergy. The complete exclusion of wheat-containing foods and environmental exposure is the most efficient allergy management to avoid the adverse reactions, which can be severe and occasionally life threatening. Therefore, the assay for accurate detection of wheat residues is demanded urgently for appropriate labeling guidelines and consumer safety. Thus, a sandwich enzyme-linked immunosorbent assay (sELISA) targeting multiple wheat protein fractions was fabricated in the present study. The results showed that the limit of detection (LOD) and limit of quantitation (LOQ) of the constructed sELISA were 0.25 and 0.5µg/g with high specificity for wheat. No cross-reactivity was observed in 32 foods or food ingredients tested, except barley and rye. The developed sELISA can also discriminate against many commercial foods containing declared or undeclared wheat residues except for Chinese yellow wine. Furthermore, high heat also can obtain a higher level of proteins extracted with corresponding enhanced detectability up to 100°C from heated samples and 160 °C in baked samples. PRACTICAL APPLICATION: Wheat is the most common food ingredient and wildly applied in various processed foods. However, wheat can cause severe and life-threatening symptoms in some allergic patients and must be labeled and tested accurately to protect those with a wheat allergy. Developing a new test assay can serve as a powerful tool for food manufacturers and regulatory agencies to accurately quantify wheat residues in processed foods and ensure their absence due to unintended contamination.