Mycotoxins: Hidden Danger in Food

What are mycotoxins?

Several hundred different mycotoxins have been identified, but aflatoxins, ochratoxin A, patulin, fumonisins, zearalenone and nivalenol/deoxynivalenol are the most frequently detected mycotoxins that are of interest to human health and livestock. As a result of mold contamination of crops both before and after processing, mycotoxins occur in the food chain. Mycotoxin contamination may occur either directly from the ingestion of infected food or indirectly through animals fed with tainted feed, in particular from milk.

Mycotoxins, the secondary metabolites of low molecular mass (MW ~700 Da) formed predominantly by Aspergillus, Penicillium, and Fusarium, are highly noxious substances in animals and humans. Not all mycotoxins, however, are labelled as such, such as penicillin, which is commonly used as an antibiotic.

Fig. 1 Mycotoxin may occur through several contamination mechanisms in food and agricultural products, at any point of production, distribution, transportation, and storage. Temperature, relative humidity, fungicides and/or fertilisers, the association between the colonising toxigenic fungal species, method of subtraction and nutritional factors, geographical location, genetic requirements, and insect infestation are factors that influence mould growth and mycotoxin development.

Mycotoxins commonly found in food and why they are of concern

The consequences of such food-borne mycotoxins are acute, with signs of serious illness progressively occurring following ingestion of mycotoxin-contaminated food items. Certain mycotoxins that exist in food have been linked to long-term health effects, including cancer development and immune deficiency. Of the several hundred mycotoxins found so far, owing to their extreme impact on human health and their prevalence in food, around a dozen, have attracted the most interest.

Aflatoxins

They are among the most dangerous mycotoxins and are produced by certain moulds that grow in dirt, rotting plants, hay, and grains (Aspergillus flavus and Aspergillus parasiticus). Crops which are infected frequently by Aspergillus spp. include Oilseeds (soybean, peanut, sunflower and cotton seeds), spices (chilli pepper, black pepper, coriander, turmeric and ginger), and tree nuts (pistachio, almond, walnut, coconut and Brazilian nuts) cereals (corn, sorghum, wheat and rice). The contaminants, in the form of aflatoxin M1 can also be detected in the milk of animals feeding infected feed. Huge doses of aflatoxin can lead to acute toxicity (aflatoxicosis) which, usually by liver damage, can be life-threatening. It has also been shown that aflatoxins are genotoxic, meaning they can damage DNA and cause cancer in animal species. There is also proof that in humans they can cause liver cancer.

Ochratoxin A

It is a natural food-contaminating mycotoxin produced by several species of Aspergillus and Penicillium. Food items, such as cereals and cereal goods, coffee beans, dried fruit, wine and grape juice, spices and liquorice, are contaminated worldwide. In animal species, Ochratoxin A is produced during the preparation of crops and is believed to cause a variety of toxic effects. Kidney damage is the most sensitive and noticeable consequence, but the toxin can also have effects on foetal growth and the immune system. Contrary to the strong proof of kidney toxicity and kidney cancer due to exposure to ochratoxin A in animals, this connexion remains uncertain in humans, but kidney symptoms have been shown.

Historical aspects of mycotoxins
Many significant outbreaks worldwide have been caused by mycotoxins. There was a 1967 epidemic, and 26 people were infected in Taiwan for up to 3 weeks due to the ingestion of mouldy rice. An epidemic of human-affecting aflatoxicosis, recorded in India, led to 100 deaths in 1974. In India in 1995, another outbreak was recorded, affecting 1424 individuals due to fumonisin-contaminated sorghum and maize. An outbreak of aflatoxicosis in eastern Kenya led to 317 cases and 125 deaths between January and June 2004.
 
Future Prospect: Impact of Growing Population and Ongoing Climate Change on Mycotoxin

The global population is expected to exceed 8.2 billion people by 2030, and with 842 million people projected to be undernourished in the 2011-2013 period, the availability of food will certainly pose a growing problem in the next decades (FAO, 2014). In essence, this situation would have an important negative effect on the supply of food (FAO, 2014). It should be noted that the presence of hazardous substances (such as mycotoxins) in international markets also limits or decreases the marketability of food products.

There is now general agreement that at an alarming pace the world is warming. Mycotoxigenic Aspergillus flavus, for example, is able to thrive under conditions of high temperatures and drought. For example, in Serbia, where no pollution has existed before, the effects of climate change have been observed, but extremely hot and dry weather in 2012 resulted in 69 per cent of AF-contaminated maize. A similar case was also found in Hungary, where the rise in pollution of AFs could be attributed to climate change.

Countries such as Brazil and Argentina are the world's biggest agri-food exporters and areas of Asia, including China and India, are known as hot spots for the effects of climate change. Therefore, from a food security standpoint, it is important to address a more detailed forecast of the impacts of climate change on mycotoxins in order to mitigate disrupted food safety, which can have detrimental social implications.

Effect on economy:

Mycotoxin's key impact on national economies can be listed in five ways:

1. Losses in crop yield due to toxigenic mould diseases.
2. Decrease in commercial value due to food and feed polluted.
3. Losses in human and animal wellbeing related to adverse impacts of mycotoxin-contaminated ingestion of fruit and fodder.
4. Price of Mycotoxin Analysis.
5. Strategies for managing infection of mycotoxin.

Economic impacts are felt by the agricultural chain, such as plant and animal producers, in particular, the cereal industry, consumers, and, in short, all farm-to-fork initiatives.

By: Duaa Mughal