Do you know what mycotoxins are, how they enter the human body, whether food containing mycotoxins is inevitably harmful, and how to avoid consuming contaminated food in daily life? This article will elaborate on mycotoxins in food to answer these questions.

Food Safety Incidents Caused by Mycotoxins

Foods tend to go moldy in warm and humid seasons, with molds as the culprit. Molds carrying toxigenic genes produce mycotoxins under suitable environmental conditions. Molds belong to fungi, and their toxic metabolites are defined as mycotoxins. Aflatoxins, one of the most well-known and toxic mycotoxins, deserve special attention: the toxicity of aflatoxin B1 is 10 times that of potassium cyanide and 68 times that of arsenic trioxide. Over 400 types of mycotoxins have been identified so far, which can contaminate nearly all agricultural crops.

Mycotoxin-related food safety accidents have occurred worldwide:

In 1960, 100,000 turkeys on a farm in England died within months after eating moldy peanut meal imported from Brazil, triggering extensive research into mold contaminants. Scientists eventually isolated heat-stable aflatoxins from the spoiled feed. Massive experimental evidence confirms that aflatoxins B1, G1 and M1 are potent liver carcinogens for animals.

From 1985 to 1992, outbreaks of human and livestock poisoning caused by deoxynivalenol occurred in southern China, linked to scab wheat and moldy corn.

In 1953, patulin led to a mass poisoning incident among dairy cows in Japan.

Major Mycotoxins Threatening Public Health in China

Below are key mycotoxins posing great risks to Chinese residents and their susceptible contaminated foods:

1. Aflatoxins (B1, B2, G1, G2, M1, M2)

Long-term intake of aflatoxin-contaminated food causes chronic poisoning and liver cancer. Aflatoxin B1 commonly pollutes peanuts, soybeans, corn and their processed products. Aflatoxin M1 is a metabolite of aflatoxin B1 in animals, mainly found in milk and dairy products.

2. Deoxynivalenol

Damages the digestive and nervous systems; major contaminants include corn, wheat and barley.

3. Patulin

A neurotoxin with teratogenic, mutagenic and carcinogenic properties, primarily detected in rotten apples and hawthorns.

4. Ochratoxin A

Exhibits nephrotoxicity and neurotoxicity, as well as teratogenic and carcinogenic effects. It contaminates grains and coffee beans.

5. Zearalenone

Mainly targets the reproductive system and central nervous system, commonly found in wheat and corn.

Two Pathways for Mycotoxins to Enter the Human Body

1. Direct exposure: Consumption of grains, fruits, fruit juices and other food products contaminated with mycotoxins.

2. Indirect exposure: Animals fed mycotoxin-polluted feed pass toxins to humans through the food chain. For instance, ochratoxin accumulates in animal tissues; aflatoxin B1 is metabolized into aflatoxin M1 in dairy cows, contaminating milk.

Strict National Standard Limits for Mycotoxins

Toxicity is closely related to dosage. China’s mandatory national standard National Food Safety Standard: Limits of Mycotoxins in Food (GB 2761) sets maximum residue limits for six high-risk mycotoxins in common foods: aflatoxin B1, aflatoxin M1, deoxynivalenol, patulin, ochratoxin A and zearalenone.

Food manufacturers and processors are required to implement control measures to minimize mycotoxin levels in finished products. Food containing trace mycotoxins below the specified limits is considered safe for consumption.

Practical Tips to Prevent Food Mold Growth

Mycotoxins penetrate deep into food tissues, are invisible to the naked eye, and highly heat-resistant — ordinary cooking methods such as stir-frying, boiling, braising and deep-frying cannot eliminate them. Preventing mold growth is the fundamental solution:

1. Purchase fresh, in-date food from formal food markets; avoid goods with long shelf storage time.

2. Store food via vacuum packaging or nitrogen flushing. Molds are aerobic microbes and barely grow under anaerobic conditions.

3. Opt for small-packaged food to shorten storage cycles.

4. Keep food storage areas well ventilated. Molds thrive in warm, damp environments; ventilation keeps food dry and cool to inhibit mold propagation and toxin production.