Comparison of Media and Influence of Petri Plate Position (Inverted or Upright) for Determining Fungal Populations in Bulk‐Stored, Dry, Seed‐Based Foods

摘要

ABSTRACTTotal populations of fungi and the presence of aflatoxigenic aspergilli were determined in 109 bulk‐stored foods predominantly from seed origin offered for sale by retail grocers. Six media were evaluated for their suitability to support development of fungal colonies. The influence of the position of the Petri dish (inverted or upright) on colony formation during incubation was determined. Overall, dichloran‐rose bengal‐chloramphenicol agar, oxytetracycline‐glucose‐yeast extract agar, antibiotic‐supplemented plate count agar and rose bengal‐chlortetracycline agar were superior to acidified potato dextrose agar for recovering yeasts and molds. Considering any given medium, the position of the plate did not significantly (P ≤ 0.05) influence colony development. Aflatoxigenic strains ofAspergillus flavusorA. parasiticuswere detected in 3.7