Mycotoxin Problems Research Articles

Natural occurrence of mycotoxins in cereals.

Besides peanuts and cottonseed, cereal grains are the most important feed and food source that occasionally are naturally contaminated with mycotoxins. The problem of mycotoxins occurring naturally in cereals, especially in corn, has become trouble-some because of changing agricultural technology. The mycotoxin problem in cereals is not restricted to any geographic or climatic region. Toxins are produced on cereals, both in the field and in storage; they involve both the grain and the whole plant. The genera of fungi most involved areAspergillus, Fusarium, Penicillium andClaviceps. Mycotoxins known to occur naturally in cereals include aflatoxins B1, B2, G1 and G2-as well as aflatoxins M1 and M2-ochratoxins A and B, penicillic acid, patulin, ergot, zearalenone, citrinin, T-2, tenuazonic acid, kojic acid and sterigmatocystin. Of these mycotoxins, aflatoxins, patulin, penicillic acid and sterigmatocystin are carcinogens.

Potential mycotoxin problems in mould-fermented sausage

A considerable proportion of the sausage consumed in many European countries is produced by a mould-fermentation process that does not involve pure culture technics. 422Penicillium cultures isolated from mould-ripened sausages produced in II European countries were analyzed for their ability to produce the following nine mycotoxins: aflatoxin B1 and G1 ochratoxin A, penicillic acid, patulin, citrinin, tremortin A, zearalenone, rubratoxin B; 88 isolates were found capable of toxin synthesis (20.9%). 44 of these cultures produced penicillic acid, 17 ochratoxin A, 11 tremortin A, 10 citrinin, and 6 patulin. 3 cultures produced both patulin and citrinin. Sausages were ripened with 6 moulds producing penicillic acid, 17 producing ochratoxin, 5 producing citrinin and 3 each producing patulin or tremortin. No mycotoxins were detected up to 70 days of ripening. Direct addition of penicillic acid to raw sausage resulted in disappearance of the mycotoxin. Amino acids normally occuring in meat were found capable of rapidly reacting with penicillic acid to produce adducts that were nontoxic to laboratory animals. Although our data indicate that consumption of mould ripened sausage is not a health hazard with respect to the 9 mycotoxins analyzed for, it is recommended that manufacturers of these products adopt pure culture technics using moulds known to be toxicologically safe.

The mycotoxin potential of peanuts (groundnuts): The U.S.A. Viewpoint

The mycotoxin potential of a plant product can be gauged by seeking answers to two of three questions basic to the mycotoxin problem; namely, ‘Which of the fungi invading the product can be toxicogenic?’, and ‘How can they become established in the product?’ Both questions relate to the quite new science of microbial synecology. In contrast, the third basic question (‘What factors are necessary for toxin production by a given toxicogenic fungus?’) relates to the much older but more complex science of microbial autecology. Fruits of Arachis hypogaea L., called ‘peanuts’ (U.S.A.) or ‘groundnuts’, are completely hypogeic in their development, and there seems to be a successional invasion of them by soil-borne or ‘field’ fungi with the result that sound mature fruits have a dormant or quiescent endogeocarpic microfloral community. Results of co-operative research in six peanut producing states (U.S.A.) and at the University of Minnesota, interpreted in the light of present-day peanut harvesting practices in the U.S.A., justify the following conclusions: (1) Aspergillus flavus can be toxicogenic under field conditions and is a serious problem. (2) Many other of the fungi from the peanut endogeocarpic community are toxicogenic under laboratory conditions. (3) Until the conditions under which such fungi may become toxicogenic are better known, their presence in lifted groundnuts constitutes a real mycotoxin potential. (4) The genera posing the greatest threat are, in estimated order of importance, Penicillium, Aspergillus (primarily because of A. flavus), Alternaria, and Fusarium. (5) Much care must be exercised with peanuts after lifting, to minimise opportunity for proliferation of such fungi. This care must be exercised at least until we determine extent to which such fungi might be expected to produce toxins in peanut fruits on the farm and during subsequent handling.