Aflatoxins

Mycopath (2006), 4(2): 27-34

Review

Aflatoxin contaminated foods and health risk perspective for Pakistani population
*Javed Iqbal Qazi and Zunera Fayyaz Environmental Microbiology Laboratory, Department of Zoology, University of the Punjab Lahore * E-mail: qazi@scientist.com

Abstract
Aflatoxin is a hepatotoxic, carcinogenic, immunosuppressive, antinutritional contaminant of manystaple food commodities. Contamination may develop as a result of fungal action before, during and harvest and during storage. Conditions favorable for natural aflatoxin contamination of foods occur at latitudes between 40°N and 40°S of the equator. Human exposure is controlled in developed countries by regulations and capitalintensive, large-scale food production systems that make such regulationspractical. But this is not the case in developing countries, wherein prevailing food production systems and economic conditions make management of aflatoxin contamination impractical. Cumulative aflatoxin exposure has been considered as one of the risks of liver cancer. Thus low exposure rates, particularly for the people in developing countries with HBV become significant. Aflatoxin contaminationlevels of various foods have been suggested to be associated with occurrence of liver cancer in Karachi. Animal studies show that aflatoxin also interferes with vitamins A and D, iron, selenium, and zinc nutrition. Risk of immunosuppression is well established in farm and laboratory animals, and immune system involvement of aflatoxin is confirmed for humans. To prevent future aflatoxicosisoutbreaks, it is necessary to explore public health interventions that promote effective production, storage, and processing of homegrown and commercial grains. In addition, risks associated with aflatoxin-contaminated foods can be reduced through the use of specific processing and decontamination procedures. It is important to note that many herbs such as garlic extract and lemongrass extract etc. possesan inhibitory role against Aspergillus flavus and its aflatoxin production. Food preparation, which incorporates such commodities, may be blended with the fungal inhibitors at the starting point of their storage/processing to prevent from the aflatoxin contamination. Restricted human exposure is ensured by strict legislation. . Key words: Aflatoxin, Food spoilage, Aflatoxins and stored grains,Risk of cancer.

Fungal Spoilage of Food
Fungi are major plant and insect pathogens and frank growth of fungi on animal hosts produces the diseases collectively called mycoses. While dietary, respiratory, dermal, and other exposures to toxic fungal metabolites produce the diseases collectively called mycotoxicoses. Mycotoxins are fungal metabolites that are present in a large part of the worldfood supply and bear potential threat to food safety (De Koe, 1999; Park & Troxell, 2002; Bennett & Klich, 2003). Molds are found in dry stored food and grains mostly as dormant structures, e.g., spores, mycelial fragments, or sclerotia. Fungal spoilage of foods involves; post-harvest diseases and losses of fruits and vegetables, deterioration of low water activity foods by xerophilic fungi,contamination of psychrotolerant or psychrophilic fungi on foodstuffs

and processed foods during storage and distribution at low temperature and spoilage of heat processed foods and soft drinks by heat-resistant fungi. In accordance with global concern about food safety, mycotoxin contamination of foods has gained much attention in recent times owing to its potential health hazards (Udagawa, 2005). Theeffects of mycotoxins are well known since antiquity. Modern trace analysis shows the wide prevalence of mycotoxins in the food chain. Aflatoxins (AFB1, AFB2, AFG1, AFG2), trichothecenes (deoxynivalenol, T-2 Toxin, HT-2 Toxin), zearalenone, fumonisins (FB1, FB2) and ochratoxin A are the most important mycotoxins worldwide. Foods of plant origin are normally contaminated more frequently and with...