High Levels Of Aflatoxins Research Articles

Aflatoxin Production in Meats. I. Stored Meats1

Aflatoxins were produced on fresh beef (in which bacterial spoilage was delayed with antibiotics), ham, and bacon inoculated with toxinogenic fungi and stored at 15, 20 and 30 C. Meats stored at 10 C were spoiled by bacteria and yeast before detectable levels of aflatoxins were produced. High levels of aflatoxins were formed in meats stored at 20 C; one sample supported the production of 630 mug of aflatoxins per g of meat, the major portion (580 mug) of which was aflatoxin G(1). Meats stored below 30 C developed higher levels of aflatoxin G(1) than B(1), but at 30 C Aspergillus flavus produced equal amounts of B(1) and G(1), whereas A. parasiticus continued to produce more G(1) than B(1).

Evolution of early hepatoma in the rainbow trout

The evolution of hepatic microscopic nodules in hatchery rainbow trout (Salmo gairdneri) fed diets containing aflatoxin has been studied. After 13 months of feeding, the histopathological examination showed microscopic nodules in the liver of 22–26 per cent of trout, wich had been fed diets containing high levels of aflatoxin. At this time a group of trout was fed a non carcinogenic diet (fresh beef liver), for other 13 months. The trials were carried out in water with a constant temperature of 8–9°C. Even though the carcinogenic stimulus was removed, trout produced hepatic tumors in 50–54 per cent of examined samples. The authors conclude that the micro-nodules, early found in the liver of trout fed carcinogenic diet, are to be considered as true neoplasms.

Production of aflatoxins B1 and G1 in chemically defined medium.

Aflatoxins B1 and G1 were produced in a chemically defined liquid medium in stationary culture. Glucose, sucrose, and fructose were satisfactory carbon sources. Organic nitrogen compounds were essential for production of high levels of aflatoxins. Complex nitrogen sources, such as yeast extract and peptone, gave higher yields than single amino acids. Aspartate, glycine, glutamine, and glutamate were good sources of nitrogen for toxin production. Little or no aflatoxin was produced when zinc, iron, or magnesium were omitted from the medium. Manganese appeared to reduce yields of aflatoxin.

Determination of aflatoxins in individual peanuts and peanut sections.

AbstractSubsamples of a given lot of peanuts may vary greatly in aflatoxin content due to extreme variability in the degree of contamination of individual kernels. A micro method, adapted from the aqueous acetone procedure recently proposed by Pons and Goldblatt for the determination of aflatoxins in cottonseed products, was developed to permit accurate determination of aflatoxins in individual kernels and kernel sections.Use of this procedure permitted the topographic distribution of aflatoxins within single kernels to be mapped and indicated that the toxins are not uniformly distributed within contaminated kernels, even when the kernel contains a high level of aflatoxins. Although wrinkling or discoloration sometimes indicated that a kernel was contaminated, this type of physical damage was not found to be a reliable indication of aflatoxin content. Also it was noted that a few apparently sound and mature kernels contained high levels of aflatoxins.