Posted: 17th April 2018
Aflatoxins, one of the most potent groups of mycotoxins, have been a known issue for decades. However, global regulations, via an alliance of 100 countries, have only been in place since 2003.
Aflatoxins are naturally occurring mycotoxins produced by many species of Aspergillus fungus most notably Aspergillus flavus and Aspergillus parasiticus. Aflatoxins can occur in many foods such as corn (maize), wheat and barley, as a result of fungal contamination before and after harvest owing to unfavourable weather conditions or poor mycotoxin management.
Both developed and developing countries are affected by aflatoxins. However, it is the developing world that is hit hardest with approximately 4 billion people being repeatedly exposed to aflatoxins, contributing to greater than 40% of the disease burden in these countries.
The major aflatoxins are B1, B2, G1, and G2 (known as Total Aflatoxin), with B1 being the most toxic. They can poison the body through respiratory, mucous or cutaneous routes, resulting in overactivation of the inflammatory response.
After entering the body, by consuming contaminated processed or unprocessed foods, aflatoxins are metabolized by the liver to a ‘reactive intermediate’, namely aflatoxin M1, an epoxide.
Aflatoxin M1 can occur in the absence of the other aflatoxins. Human exposure occurs primarily via milk and milk products from animals that have consumed contaminated feed.
With Aflatoxin B1 being of great concern it tends to be regulated more heavily. However, there are some variations from country-to-country. For example:
The maximum permitted level for aflatoxin B1 is 20μg/kg, in combination with the other aflatoxins (B2, G1 and G2) in all foods, with the exception of milk which has a maximum permitted level of 0.5μg/kg.
Higher levels of 100–300μg/kg are tolerable for some animal feeds
The maximum permitted level for aflatoxin B1 is 2-12μg/kg in nuts, dried fruits, cereals and spices, while the maximum permitted level for aflatoxin B1 in infant foods is set at 0.1μg/kg.
The maximum permitted levels for aflatoxin B1 in animal feeds is 5-50μg/kg.
Preventing aflatoxins from entering the food chain is easier said than done. However, growers and agronomists will adopt mycotoxin management techniques in order to reduce the affects of aflatoxins.
But, how do you know if aflatoxin is present in foodstuffs? Relying on visual inspection for fungus-detection alone is not going to be enough. Because the presence of fungus does not necessarily mean an aflatoxin will be present, using visual inspection methods could lead to the unnecessary loss of yield and income.
Testing for aflatoxin is unavoidable as unacceptable levels of the mycotoxin can’t progress down the food chain. Using time-consuming laboratory methods to test food samples for the presence of aflatoxin is an option. However, one of the quickest options is to use an aflatoxin rapid test.
Learn more about mycotoxin management techniques and using rapid tests to detect aflatoxins, as well as other mycotoxins in our article; why use rapid tests for mycotoxins?
© Abingdon Health 2018