Mycoflora and aflatoxin contamination in shelled pistachio nuts

AbstractA total of 143 pistachio nut samples collected during harvest, storage and processing were examined for mould growth and aflatoxin production. The mould count was in the range of 103−104 cfu g−1 and 105−106 cfu g−1 for the harvest and storage samples, respectively. The growth of Aspergillus flavus was 38‐5‐39‐5% on the surface of the shells and 6–16% on the kernels without aflatoxin production. The contamination level of A flavus varied among samples collected from different regions. Peeling off the soft shell of pistachio nuts by hand reduced the contamination risk of A flavus to kernels. The predominant flora on stored pistachio nuts were Aspergillus, Penicillium, Cladosporium, Rhizopus, while the genera of Ulocladium, Trichothecium, Aureobasidium and Eurotium were less frequent. Thirty‐five percent of the A flavus isolates produced aflatoxins on synthetic media.