FUNGAL FLORA AND MYCOTOXINS OF 6 KINDS OF NUT SEEDS FOR HUMAN CONSUMPTION IN SAUDI-ARABIA

A wide range of moulds representing several genera and species, was re corded in this study from 5 seed samples of each almond, cashew nut, c hestnut, hazelnut, pistachio nut and walnut collected from different m arkets in Ar' Ar, Saudi Arabia, The total counts of fungi were widely fluctuated between 1960-7704 and 1948-7434 colonies/g dry seeds on glu cose-Czapek's and glycerol agar media at 28 degrees C, respectively, a nd represented twenty genera, 53 species and 2 varieties of fungi. The prevalent fungi on the 2 agar media were Aspergillus flavus, A. niger and Penicillium chrysogenum. On glucose-Czapek's agar, Rhizopus stolo nifer and Aspergillus flavus var, columnaris were isolated from all 6 kinds of nut, A. parasiticus from 5 kinds and A. fumigatus from 4 kind s with high frequencies. Eurotium species were completely absent on gl ucose-Czapek's agar but they were isolated in high frequency from all kinds of nut on glycerol agar medium. The different nut samples were a nalyzed by thin layer chromatography for the presence of aflatoxins B- 1, B-2, G(1) and G(2), citrinin, ochratoxins, patulin, sterigmatocysti n, diacetoxyscirpenol, T-2 toxin and zearalenone. Aflatoxins B-1 and G (1) were detected in 3 out of the 5 samples tested of chestnut at conc entrations ranging between 20 to 60 mu g/kg. All other samples of almo nd, cashew nut, hazelnut, pistachio nut,and walnut that were analyzed were mycotoxin free.