Mycoflora and aflatoxin contamination in shelled pistachio nuts

Abstract

Abstract A 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 10 3 −10 4 cfu g −1 and 10 5 −10 6 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.