ASPERGILLUS-FLAVUS AND ASPERGILLUS-PARASITICUS - AFLATOXIGENIC FUNGI OF CONCERN IN FOODS AND FEEDS - A REVIEW

Aspergillus flavus and the closely related subspecies parasiticus have long been recognized as major contaminants of organic and nonorganic items. A. flavus, a common soil fungus, can infest a wide range of agr icultural products. Some A. flavus varieties produce aflatoxins, which are carcinogenic toxins that induce liver cancer in laboratory animal s. A. flavus var. flavus, A. flavus subsp. parasiticus, and A. nomius share the ability to produce aflatoxins. Identification of the A. flav us species group is mainly based on the color and macroscopic and micr oscopic characteristics of the fungus. A. flavus growth and aflatoxin biosynthesis depend on substrate, moisture, temperature, pH, aeration, and competing microflora. The growth of A. flavus and aflatoxin produ ction are sometimes unavoidable. Aflatoxins are considered natural con taminants; the ideal control approach is prevention of mold growth and aflatoxin production. The detection of members of the A. flavus speci es group in foods and feed is generally carried out by using plate tec hniques such as surface spread or direct plating. Research on alternat ive fungal detection methods is still in its infancy. Few immunoassay techniques have been investigated in this regard. Aflatoxins are gener ally analyzed by chemical methods, although immunochemical methods whi ch use antibodies are becoming common analytical tools for aflatoxins.