Mycotoxin formation in hulless barley during granary storage at 15 and 19%moisture content

Eleven-kilogram parcels of hulless barley (Hordeum vulgare L. cv. Condor) a t 15 and 19% initial moisture content were kept in simulated storage in a M anitoba farm granary for 20 weeks (June 1996-October 1996) to determine bio tic and abiotic changes and mycotoxin production. Temperature, moisture con tent, CO2 levels, ergosterol content, seed germination, microfloral infecti on, and the presence of major mycotoxins were monitored. Ochratoxin Al citr inin and sterigmatocystin reached mean levels of 24, 38 and 411 ppb by 20 w eeks in the 19% moisture content barley, but were absent in the 15% moistur e content barley; no other mycotoxins were detected. Penicillium species an d Aspergiullus versicolol (Vuill.) Tiraboschi comprised the predominant mic roflora. The effect of storage time was apparent at both 15 and 19% moistur e content for grain temperature, Alternaria alternata (Fr.) Keissler, Penic illium species and Aspergillus versicolor. At 19% moisture content, storage time also affected moisture content, CO2 level, ergosterol content, seed g ermination, and mycotoxin production. At 19% moisture content, elevated erg osterol levels at weeks 4 and 8 appear to offer early warning of the appear ance of sterigmatocystin at week 12, and of ochratoxin A and citrinin at we ek 20. Crown Copyright (C) 1999 Published by Elsevier Science Ltd. All righ ts reserved.