What are mycotoxins?
Mycotoxins are toxic metabolic products of molds that can be found in many foods. They are mainly produced by fungi of the genera Aspergillus, Penicillium and Fusarium and are particularly problematic when food is stored in warm and damp conditions. Mycotoxins serve as a defense mechanism for fungi against other microorganisms and can be dangerous for humans and animals.
Biochemically, mycotoxins belong to a heterogeneous group of organic compounds, including polyketides, alkaloids and peptides. Their toxicity varies depending on their structure and concentration. Some mycotoxins are harmful even in very small quantities, while others only cause health problems after chronic exposure.
Where do mycotoxins occur?
Mycotoxins can be found in numerous foods, especially in:
- Cereals (e.g. wheat and corn)
- Nuts (e.g. pistachios and hazelnuts)
- Dried fruits (e.g. raisins and dates)
- Herbs & spices (e.g. chili and pepper)
- Cocoa & coffee
- Beer & wine
Poor storage conditions promote the growth of mold and thus increase mycotoxin contamination in food. Climatic changes such as high humidity and temperatures can also promote the formation of mycotoxins.
Why are mycotoxins harmful to health?
Mycotoxins can cause serious health problems. The greatest risks include:
- Liver toxicity (Aflatoxins are particularly dangerous to the liver)
- Cancer risk (Some mycotoxins are classified as carcinogenic, especially aflatoxins and ochratoxin A)
- Impairment of the immune system (Mycotoxins can damage immune cells and promote infections)
- Damage to the nervous system (Neurotoxic effects from long-term exposure, especially through fumonisins)
- Hormonal disorders (zearalenone acts like an oestrogen and can affect the hormonal system)
Children, the elderly and immunocompromised people as well as pregnant people are particularly at risk. Animals can also fall ill from contaminated feed, which has an indirect effect on human nutrition.
Which mycotoxins are particularly relevant?
There are numerous mycotoxins, but some are particularly frequently detected in food:
- Aflatoxins (Aspergillus) → carcinogenic, found in nuts, dried fruit and spices
- Ochratoxin A (Penicillium, Aspergillus) → toxic to kidneys and liver, in coffee, wine & cereals
- Deoxynivalenol (Fusarium) → nausea-inducing, in cereals
- Fumonisins (Fusarium) → carcinogenic, often found in corn
- Zearalenone (Fusarium) → hormonally active, often in cereals, can cause reproductive disorders
- T-2 & HT-2 toxins (Fusarium) → immune-damaging, in cereals, irritating to the skin
Some of these toxins can be reduced in food by certain processing methods, but they are often heat-stable and cannot be completely removed.
How are consumers protected from mycotoxins?
There are various protective measures to reduce exposure to mycotoxins:
- Strict limits: the European Union sets legal maximum levels for mycotoxins in food and animal feed.
- Quality controls & food analyses: Modern analytical methods make it possible to detect even the smallest quantities. These tests are carried out regularly by food authorities and manufacturers.
- Optimized storage & processing: Proper drying and storage of food reduces mold growth. Temperatures and humidity levels in storage facilities must be closely monitored.
- Technological processes: Various methods are used in food processing to reduce mycotoxins, including physical, chemical and biological processes such as ozone treatment or the use of binding agents in animal feed. The latter is strictly prohibited in food.