Influence of gamma-radiation on the occurrence of toxigenic Pennicium strains and mycotoxins production in different feedstuffs

Abstract

One hundred and fifty random poultry and animal feed samples were collected and analyzed for Penicillium toxins. The effect of gamma irradiation on the production of mycotoxins in feeds was studied. The results revealed the isolation of 12 Penicillium species. Out of 179 pure cultures of Penicillium species only 104 isolates (58%) were mycotoxin-producers. The isolates have the ability to produce, citrinin, patulin, ochratoxin A, rubratoxin B and cyclopiazonic acid with variable levels. Of the 150 samples examined, 70 were positive for Penicillium toxins. Analysis of feed samples revealed the occurrence of citrinin, ochratoxin A, cyclopiazonic acid and rubratoxin B. Irradiation at a dose 4.0 kGy reduced the Penicillium growth greatly relative to unirradiated controls and there was no growth and mycotoxin production at dose 5.0 kGy. Treatment of feed samples with 10 kGy detoxified citrinin by 92.5 to 97.5% and ochratoxin A by 68.8 to 78.5%. A dose of 15 kGy was sufficient for complete destruction of citrinin and by 90 to 95% for ochratoxin A. Patulin, cyclopiazonic acid and rubratoxin B were not detect at 5.0 kGy.

Egyptian Journal of Biotechnology Vol. 25 (1) 2007: pp. 130-144