Aspergillus species in retail samples of pistachio, walnut and hazelnut in Kerman, Iran

Nuts are among Iran’s most important crops consumed by many people due to their nutritional and nutraceutical properties. Fungi from the genus Aspergillus contaminate them during pre- and post- harvest stages. Aspergillus species are responsible for various agricultural products' secondary spoilage, and they can produce mycotoxins harmful to humans and animals. The present study evaluated the fungal contamination of nuts marketed in local stores in Kerman. Samples of pistachio, walnut, and hazelnut were collected throughout Kerman province, Iran, to characterize Aspergillus species contaminating nuts marketed in retail shops. Aspergillus species were examined by morphological and molecular criteria to explore the diversity of this genus. The phylogenetic relationships of these species were determined using sequences from partial β-tubulin and calmodulin sequences. Aspergillus species were identified as A. flavus, A. parasiticus, A. arachidicola, A. tamarii, A. caelatus, A. nomius, A. leporis, A. quadrilineatus, A. unguis, A. spelunceus, A.ochraceus, A. auricomus, A. westerdijkiae, A. montevidensis, A. pseudoglaucus, A. subalbidus and A. taichungensis. Populations of Aspergillus species on nuts, how these populations vary among different types of nuts, and their mycotoxin production potential are discussed.