Mycotoxins aflatoxins

For zinc, copper and iron, the 31st CCFAC in 1999 recommended that the relevant Commodity Committees take appropriate steps to remove the provisions concerning zinc, copper and iron from the contaminant section of all commodity standards. These provisions should be considered as quality parameters and can be included in the standards as such.13 Moreover, there are draft standards for the mycotoxins aflatoxins, ochratoxin A and patulin, and Position Papers are becoming available for fumonisins and zearalenone. 

Of the 15 spices marketed in India and screened by Saxena and Mehrotra (1989) for the mycotoxins, aflatoxin, rubratoxin, ochra-toxin A, citrinin, zearalenone and sterigmato-cystin, samples of coriander and fennel were found to contain the largest number of positive samples and mycotoxins. Other spices like cinnamon, clove, yellow mustard and Indian mustard did not contain detectable amounts of the mycotoxins tested. Aflatoxins are the most common contaminants in the majority of samples, levels being higher than the prescribed limit for human consumption. 

Aspergillus flavus and A. parasiticus produce the mycotoxin aflatoxin Bl. Aflatoxin B1 is a carcinogenic chemical that can cause liver cancer. Both ingestion and inhalation are proven exposure routes. Aflatoxin Bl has been found on contaminated grains, peanuts, and other foodstuffs. A. flavus and A. parasiticus are not commonly considered an indoor contaminant, unless the grains, peanuts, cereal-based animal food, or other foodstuffs are stored in an indoor environment. 

Of all the known mycotoxins aflatoxin B1 (AFBl) is the major and best studied one because it possesses exceptional toxicity and is widespread in market foods and foods in principle (such as peanuts, maze, cotton seeds). 

Acidulants, sweeteners, flavors, Anitoxidants and preservatives Colors and dyes Vitamins Contaminants Mycotoxins (aflatoxins)... 

The analysis of food contaminants, in particular any toxic or biologically active residue, is important for public health or quality control reasons.19 Examples are mycotoxins (aflatoxins) and pesticide and drug residues. Sample preparation is typically elaborate and might involve deproteinization, solvent extraction, and clean-up via solid-phase extraction (SPE).The use of highly sensitive and specific LC/MS/MS is increasing and has simplified some of the sample preparation procedures. 

The persistent chemical agents which could be used in a foodborne attack, aimed at poisoning human consumers, include the nerve agent VX, any of the mycotoxins—aflatoxin, T-2 toxin, nivalenol (see Appendix A for discussion of their toxicology)—and compounds such as ricin produced from the castor bean plant. Chapter 5 should be consulted for a full discussion on natural toxins. These chemicals, combined with the biotoxins listed above, could potentially be used in the food supply. This would not be an easy task since many of these agents are toxic to animals and thus might kill the host, preventing dissemination into the food distribution system. 

Sterigmatocystin (15) is both a carcinogenic hepatotoxin and a biosynthetic precursor to the important mycotoxin, aflatoxin, and, as such, its biosynthesis pathway has been studied quite extensively (607-608). This is purported to begin with a single C20 polyketide unit, which is folded in only one mode to form averufin (103) and then sterigmatocystin (15) (609). The authors provided evidence to support the identity of this compound through the synthesis of a common product from both it and from a... 

Bando T, Shishido K (1997) Enantioselective Access to the Mycotoxin Aflatoxin B2. Synlett 665... 

As made evident in Table 2, immunoassays are also in routine use for analysis of mycotoxins, a group including the most dangerous and analytically elusive food-related toxins. In spite of the small structural differences within specific groups of mycotoxins (aflatoxins, ochratoxins, trichothecenes), assay specificity toward the other mycotoxin groups is always total. Determination of AEBi, toxin T-2, and ochratoxin A in a single extract from barley grains has been reported. Mycotoxins may be determined in crude extracts of various foodstuffs at concentration over 20 ng per kg. This detection limit can... 

The line between catabolic and anabolic activity is as nebulous as that between primary and secondary metabolism. The mycotoxins aflatoxin and patulin give every appearance of being catabolic in nature (Haslam, 1986). Many secondary metabolites possess elements of structure that directly parallel those observed in the catabolism of primary metabolites such as a-amino acids (Haslam, 1986). 

Among all mycotoxins, aflatoxins are the most toxic, widespread, and the strongest natural carcinogens (Table 11.2). The International Agency for Research on Cancer (lARC) has defined aflatoxin B1 (AFBl) as a carcinogen [11]. 

Due to adsorptive property, clays can adsorb a variety of toxic substances, such as strychnine, mycotoxins, aflatoxin and toxins. Clay can provide active protection against disturbances dming gastrointestinal transit. However, if the toxin is incubated with smectite for 24 h beforehand, no increase in the rate of gastric emptying and small intestinal transit occurs. Smectite can also adsorb the enterotoxin of Clostridium difficile. In rats, this toxin causes intestinal permeability to increase through hyperseeretion of colonic water. 

Mycotoxins Aflatoxin Fumonisins RubialOKin Sporidesmin Sterqpnalocystin Swine pouhty, dogs Eloises, swine Rare, all animals Sheep Rare, all animals... 

It is now possible to correlate the formation of specific DNA adducts and mutation in human cells. Experiments with the mycotoxin aflatoxin Bi have been completed and indicate that the probability of a covalently bound aflatoxin molecule, giving rise to a mutation to 6TG resistance, is about 1/200. We are also studying UV-induced dimer formation and DNA repair in relation to mutation in human lymphoblasts. 

Reiss, J. (1976). Mycotoxins in foods inhibition of the formation of mycotoxins (aflatoxins) and patulin and sterigmatocystin in whole wheat bread by sorbic acid and sorboyl palmitate. Dtsch Lebensm Rundsch, 72, 51-54. 

The biosynthesis of the important mycotoxin aflatoxin (86) continues to attract considerable attention. The generally accepted pathway is summarised in Scheme 19, but there are still major gaps and mainy problems to be solved in this ccxnplex pathway. Further evidence that averufin (82) is an obligatory intermediate... 

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