Development of a sensitive polyclonal antibody-based competitive indirect ELISA for determination of citrinin in grain-based foods

ABSTRACT

A sensitive competitive indirect enzyme-linked immunosorbent assay (ciELISA) was developed for the detection and quantification of citrinin (CIT) in grain-based food samples. The limit of quantification (IC₂₀) of the established method was 0.10 ± 0.02 ng mL⁻¹, with the limit of detection (IC₁₀) being 0.04 ± 0.007 ng mL⁻¹ in wheat and corn flour matrices with a coefficient of variation (CV) less than 20%. The assay was very specific to CIT and showed no cross-reactivity with other mycotoxins (OTA, T-2 toxin, HT-2 toxin, DON, patulin and zearalenone). In spiked wheat and corn flours, the recoveries ranged from 86.6% to 115.6% with CVs of less than 20%. The effectiveness of this method was verified by participating in a proficiency test (PT) from the Food Analysis Performance Assessment Scheme (FAPAS) 17181 corn flour. A successful z-score (−0.6) for this PT sample showed that the present method is comparable to the instrumental methods used by other laboratories in the PT testing scheme. A small survey of grain-based foods was conducted using this method and CIT was detected in 43% of the samples up to a concentration of 17.7 ng g⁻¹. This method is suitable for sensitive and rapid quantitation of citrinin in wheat and corn matrices.

KEYWORDS:

• Citrinin
• polyclonal antibody
• ciELISA
• z-score
• grain-based foods

Acknowledgments

The authors give sincere thanks Eric Braekevelt and Michael Abbott for their helpful comments during the editing of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethical approval

This article does not contain any studies with human subjects. All animal experiments that described in the present study were performed at CER Groupe, Belgium following all institutional and national guidelines for the care and use of laboratory animals.