Mycotoxin production in amber durum wheat stored at 15 and 19% moisture content

Abstract

Ochratoxin A and citrinin developed in 11 kg parcels of amber durum wheat at 15% and 19% initial moisture content (MC) exposed to simulated bulk storage in a Manitoba granary for 60 weeks between July 1984 and September 1985. Other biotic and abiotic variables were monitored throughout the storage period. Ochratoxin A reached maximum levels of 11.8 and 0.11 ppm at 19 and 15% initial MC, respectively, during weeks 44–48; citrinin reached levels of 80.0 and 0.65 ppm at these respective moistures during the same period. The effect of 19% initial MC was significantly greater for the following variables: ochratoxin A, citrinin, Aspergillus flavus, Aspergillus glaucus group species, Alternaria species, Aspergillus versicolor bacteria, fungal propagule count, seed germination, O₂, CO₂, moisture content, and fat acidity. Principal component analysis indicated that the first two components, describing >60% of the variability in the data, partially defined the ecological relationships leading to mycotoxin production in the stored durum wheat system.

Keywords:

• Ochratoxin A
• citrinin
• durum wheat
• storage ecology
• principal component analysis