Development of a sensitive and Ara h 2 specific competitive ELISA for the quantification of Peanut

Abstract

The quantification of peanut in processed foods remains a challenge with currently available immunochemical methods. In this study, we used Ara h 2 purified from light roast peanut flour to raise polyclonal Ig G antibodies in rabbits. IgG antibodies were purified from high-titer rabbit sera and a competitive inhibition ELISA targeting the peanut protein Ara h 2 was developed. The developed Ara h 2 ELISA was highly sensitive with a quantification range and limit of detection (LOD) of 0.8–6.8 ppm and 0.5 ppm (mg/kg) of peanut protein, respectively. The developed ELISA outperformed both the Neogen Veratox® Peanut ELISA and the Morinaga Peanut ELISA methods in recovering peanut from fried and High Pressure Processed (HPP) (5 min) pastry squares that were incurred with peanut. With pastry samples that were subjected to much harsher conditions of HPP at 600 MPa for 30 min or baking at 190 °C for 20 min, the performance of the developed assay was comparable to that of the Morinaga ELISA. Of a total of 45 food ingredients tested for cross reactivity, matrix interference was observed with only cloves.