Aflatoxin degrading

Microbial systems show similarities to the animal systems, and Hamid and Smith [36] have clearly demonstrated the involvement of a microsomal enzyme system in aflatoxin degradation in A. flavus. The degradation of aflatoxins by cell>free extracts of A flavus was enhanced by NADFH... 

The synthesis of the (i) 4-hydroxy-6-methoxytetrahydrofuro[2,3-6]-benzofuran ring (116), a degradation product of natural substances of the sterigmatocystin series, is similar,318 as is the synthesis of the dihydro derivative (117) from the o-acetylated acetaldehyde (118), a nonisolated intermediate which is ring-closed to 119 and then heated in toluene to give 117. The last is the starting point for the synthesis of aflatoxin M4 (49).153... 

Procedures aimed at reducing or detoxifying aflatoxins and/or their effects have been reviewed by Phillips et al. (35), and include technological procedures for food and feeds and chemical degradation, as well as biocontrol and microbial inactivation, dietary modification and chemoprotection, and reduction in toxin bioavailability via selective chemisorption with clay. 

Diluted solutions of aflatoxins are not very stable, since they are degraded under UV light. Therefore it is necessary to renew them regularly. It is worth preparing a concentrated stock solution [10 yug/ml in benzene acetonitrile (90 10 or 97 3)] that is sufficiently stable and then preparing working solutions whenever necessary. 

Chemical detoxification processes or decontamination will include degradation, destmction and/or inactivation of the mycotoxin. In any such process the reduction of the mycotoxin to safe levels should not result in toxic degradation products or reduce the palatability or nutritional properties of the commodities. Aflatoxin has been the subject of most studies and only a relatively small number of these offers any hope of success. There is as yet no FDA or EC fully approved method for aflatoxin detoxification in human foods. Current methods in advanced stages of approval use ammonia in the gaseous form or as an ammonium hydroxide solution at various temperatures, pressure, moisture contents and reaction time to degrade aflatoxins in various animal feedstuffs. There have been extensive studies using two processes, viz ... 

Finally, biological detoxification or biotransformation, or degradation of mycotoxins, especially aflatoxin by microbial systems to a metabolite(s) that is... 

A wide range of chemicals have been tested for the ability to degrade and inactivate aflatoxins. However, although a number of these chemicals can react to destroy aflatoxins effectively, most are impractical, too expensive or potentially unsafe because of the formation of toxic residues, or the perturbation of the nutrient content of the food. Two chemical approaches that have received considerable attenhon are ammoniation and reaction with sodium bisulphite. 

Studies have shown that treatment of aflatoxin-contaminated corn with ammonia is an effective detoxification approach. Ammonia appears to produces hydrolysis of the lactone ring and chemical conversion of the parent compound to numerous products that exhibit greatly reduced toxicity. Similarly sodium bisulphite reacts with aflatoxins to form water soluble degradation products. 

World Health Organization (2006) GEMS/Food Consumption Cluster Diets. Geneva, Department of Food Safety, Zoonoses and Foodborne Diseases, Revision August. Yazdanpanah, H., MohammadI, T., Abouhossain, G.A. Cheraghall, M. (2005) Effect of roasting on degradation of aflatoxins In contaminated pistachio nuts. Food Chem. Toxicol. 43, 1135-1139. 

Aflatoxin has also been found to be degraded by various Rhizopus spp. to an intermediate metabolite previously reported in A. flavus as aflatoxin B, and in A parasiticus as parasiticol. Ciegler et al. [59] screened over 100 microorganisms for their ability to either d ade or... 

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