Irradiation control of toxigenic isolates from fungal flora contaminating spices on zagazig markets

Fourteen fungal species were isolated from six kinds of spices (namely black pepper, chilli, cumin, aniseed, caraway and cinnamon) belonging to the genera aspergillus, penicillium, paecilomyces, epicoccum and trichoderma. The production of aflatoxins were detected for all fungal isolates (121 isolates) in synthetic medium (sabouroud's yeast extract medium) by thin layer chromatography and biological method. A. flavus (isolated from black pepper) A. niger (isolated from chilli) A. ochracues (isolated from cumin) and penicillium notatum (isolated from caraway) produced aflatoxins B2, B1,B2 and G1 respectively. The highest amount of toxins was produced by A. flavus. It has been found that irradiation dose 5 kGy completely inactivated the fungal flora contaminated all kinds of spices, Whereas the irradiation dose 3 kGy was the inhibitory dose for growth of toxigenic fungi and completely inhibited the production of aflatoxins. On the other hand the inhibitory effect of tested spices on the growth of toxigenic fungus A. flavus as well as on the production of aflatoxins was also investigated. It has been found that 2% of cinnamon or cumin completely inhibited the production of aflatoxin produced by A. flavus