A Sensitive Sandwich ELISA for the Rapid Detection of Mung Bean Protein: Development and Evaluation of the Effect of Thermal Processing on Detection

Abstract

The mung bean allergen has not yet attracted attention on a global scale for the potential hazards it poses to allergen-sensitive individuals. In the current study, a sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of trace amounts of mung bean proteins was established. Mung bean protein-specific antibodies produced in rabbits and mice immunized with protein extracted from mung bean flour were used as the capture and detection antibodies in the ELISA. The ELISA had a limit of detection of 4.99 ng/mL and did not show any cross-reactivity with nine different foods, which potentially coexisted in foodstuffs. Accuracy and repeatability were validated by spiking and recovery of mung bean protein in oat meal, milk, and soybean milk. The suitability of the ELISA for the detection of mung bean protein in thermally processed samples was established by subjecting mung bean protein, mung bean powder, and defatted mung bean powder to dry or moist heating. The results demonstrated that the accurate quantitation of mung bean protein can be established for samples processed by dry heating at ≤150 °C. Lower detection results could not be avoided for mung bean proteins subjected to either dry heating at temperatures >150 °C or with moist heat, most probably because of changes in protein solubility and structure of the mung bean protein.