Mycotoxin contamination of animal feedingstuff: detoxification by gamma-irradiation and reduction of aflatoxins and ochratoxin A concentrations

Abstract

Mycotoxins are fungal secondary metabolites identified in many agricultural products screened for toxigenic moulds. They have been reported to be carcinogenic, teratogenic, tremorogenic, haemorrhagic and dermatitic to a wide range of organisms. With the increasing stringent regulations for mycotoxins imposed by importing countries such as those of the European Union, many cereals that are not safe for human consumption are used in formulations intended for animal feed. Gamma-rays are reported in the scientific literature to destroy ochratoxin A and aflatoxin in food crops and feed. The present study provides preliminary data for establishing the effect of dose of gamma-irradiation, ranging from 0 to 15 kGy, on aflatoxins and ochratoxin A reduction in commercial animal feed. The mycotoxin levels were determined by means of immunoaffinity clean-up (IAC) and HPLC with fluorescence detection (HPLC-FLD). The maximum reductions found at 15 kGy were 23.9%, 18.2%, 11.0%, 21.1% and 13.6% for ochratoxin A, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂, respectively. Results showed that the gamma-rays even at 15 kGy were not effective in the complete destruction of ochratoxin A and aflatoxins in the tested feed.

Keywords:

• mycotoxin
• commercial animal feed
• aflatoxins
• ochratoxin A
• gamma-irradiation

Acknowledgements

The authors thank MIUR and Dr. A. Parlato of the Dipartimento di Energia, Ingegneriadell’Informazione e ModelliMatematici of the University of Palermo for taking care of γ-ray irradiation in the IGS-3 irradiator.