Aflatoxins are highly toxic secondary metabolites produced by the molds Aspergillus flavus and Aspergillus parasiticus. This group of mycotoxins, which is particularly toxic to the liver, poses a risk in many food groups including nuts, dried fruits, spices, herbal teas, and cereal products.
Aflatoxins, especially aflatoxin B1, are carcinogenic (cancer-causing) and mutagenic (causing mutations in the genetic material). Epidemiological studies have found a higher incidence of primary liver cancer and cirrhosis in populations consuming aflatoxin-contaminated foods. Additionally, it has been proven in experimental animals that aflatoxins have teratogenic (causing developmental abnormalities in the womb) and immunosuppressive (weakening the immune system) effects.
In dried foods, mold is the most significant factor shortening shelf life. Mold development can begin on tree branches and appear in the garden. Mold formation can continue if products are left in heaps or if improper drying methods are used after harvest. Moreover, storing products in plastic sacks for extended periods or under unsuitable storage and transportation conditions can increase mold formation. Especially in risky foods, toxin formation can occur and rapidly contaminate the entire batch under inappropriate humidity-temperature conditions.
While mold formation is visible to the eye, detecting aflatoxins visually is very challenging. A moldy food may be risky for aflatoxins, but the absence of visible mold does not make the food safe from aflatoxins.
Aflatoxins are highly resistant to heat and cannot be destroyed by heating or cooking processes applied to foods. Therefore, consuming food that is safe from aflatoxins is the only reliable method.
Aflatoxin Issues in Foods
Aflatoxins are the biggest food safety issue in the export of nuts and dried fruits. In Turkey, the aflatoxin problem became prominent in 1967 when 10 tons of hazelnuts sent to Canada and pistachios exported to the USA in 1971 were returned due to aflatoxin contamination.
RASFF (Rapid Alert System for Food and Feed) Data on Aflatoxins
RASFF is an international system aimed at ensuring food and feed safety by providing rapid information sharing among European Union member countries and taking measures against all risks that may arise.
Returns of products due to aflatoxins and the countries from which these products originated are reported daily in the RASFF system. The majority of non-compliant batches of plant products sent from Turkey to EU countries are due to aflatoxins.
The table below shows the most reported hazard categories and countries of origin. As seen, Turkey is among the top 10 countries with the highest number of notifications for the aflatoxin hazard group in dried fruits and nuts. (Source: RASFF 2021 annual report)
Aflatoxins in foods should be closely monitored, and food safety management systems must be established in businesses to ensure that products are analyzed before being released to the market.
Even though first-class products are sent to European countries after analysis, the opposite can lead to serious economic damage due to returns. If there are numerous returns related to aflatoxins at border controls, consider the state of domestic markets where sufficient inspections are lacking.
Additionally, the public is not transparently informed about what happens to the returned tons of products. This raises the question of whether the returned products are being sold in the domestic market.
To protect against aflatoxins, it is important to shop from reliable places where aflatoxin analyses are conducted, avoid products that are improperly stored or sold openly, and store foods at home under appropriate conditions (in a cool and dry place).
