Muscat, Dec 10 - Toxigenic fungi invade the agricultural commodities in the field prior to harvest or during post-harvest operations such as drying or curing and in storage, and secrete aflatoxins. Aflatoxin contamination is a main problem in a wide range of agricultural commodities including peanut, corn, pistachio nuts, almonds, rice, wheat, and spices like chilli, black pepper and turmeric. Several recent studies have reported the occurrence of aflatoxins in dates, dried apricot and prunes as well. One such study was conducted by Rethinasamy Velazhahan and Abdullah Mohammed al Sadi of Department of Crop Sciences, College of Agricultural and Marine Sciences,Sultan Qaboos University.
Among the aflatoxins, AFB1 is the most prevalent and dangerous mycotoxin to humans and considered as one of the most potent hepatocarcinogens known. The International Agency for Research on Cancer classified the AFB1 as class I human carcinogens. Consumption of aflatoxin-contaminated food products leads to the disease called “aflatoxicosis” in humans. Acute and chronic exposures to aflatoxins result in a diverse range of symptoms including liver cancer, immunosuppression, poor weight-gain, and rapid death. When cow, sheep, goat, camel or other lactating cattle consumes AFB1-contaminated feeds, AFM1 will be formed as a result of the metabolic process in the liver of animals and excreted in the milk.
Several studies reported the presence of residual aflatoxins in the liver and meat of broilers when fed with aflatoxin-contaminated feeds. In the case of laying hens, aflatoxins and their metabolites can be found in the eggs. Humans are exposed to aflatoxins directly by ingestion of aflatoxin-contaminated foods, or indirectly by consumption of aflatoxin-contaminated eggs, meat, milk and dairy products.
The presence of aflatoxins in the food chain threatens people’s livelihood, food security and human health. Aflatoxins have been detected in the blood of pregnant women and in breast milk. Because of the high cost of analysis and non-availability of dedicated research laboratories, only a few countries are effectively monitoring the levels of aflatoxins in their food products. The presence of toxin-producing fungi on the agricultural products may not be obvious sometimes because, the molds can be removed during the processing of agricultural products. However, the aflatoxins, which are produced by the toxigenic fungi, are extremely stable under most conditions of storage, handling and processing.
Storage of food products under inappropriate conditions (high temperature and moisture levels) may also favour the growth of toxigenic molds and subsequent production of aflatoxins. A high level of exposure of people to aflatoxins is a serious threat to public health. Increasing awareness among families, farmers, consumers and traders about health impacts associated with aflatoxins and imposing appropriate regulatory measures on import of high-risk agricultural commodities will help in reducing exposure of people to aflatoxins.
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