Immunoanalytical methods for ochratoxin A monitoring in wine and must based on innovative immunoreagents

Abstract

Immunochemical methods are highly deployed in analytical laboratories worldwide for monitoring the incidence of mycotoxins in the food chain. Nevertheless, most conventional immunoassays for ochratoxin A (OTA), including commercial kits, show limitations to robustly determine this mycotoxin in grape-derived products below regulated levels (2 ng/mL). Herein, two rapid tests for sensitive OTA determination in wine and must were developed capitalizing on a collection of bioconjugates from innovative synthetic haptens and monoclonal antibodies with subnanomolar affinity. The ELISA (LOD = 8 pg/mL) showed excellent performance in recovery studies, and it was applied to survey commercial wines and musts for OTA contamination. Concerning LFIA, validation according to the Commission Regulation 519/2014 showed that samples exceeding 2 ng/mL were properly scored as uncompliant. More importantly, illegal samples provided a complete inhibition of the test signal, making this test an easy-to-use, rapid, and convenient screening method for in-house control of OTA in wineries.

Keywords: Competitive immunoassay; Dipstick; Food safety; Hapten; Monoclonal antibody; Mycotoxin.