Aflatoxins, The Hidden Poison in Foods

Author

Specialist Dietitian Merve Yeşim Küçükboz Taşkın

Founding Dietitian Bona Vita Nutrition Consultancy

"Aflatoxins pose a great danger to food safety."

What is aflatoxin?

Aflatoxin, which has been frequently mentioned in the field of food safety in our country and in the world, is one of the many chemical substances produced by some of the molds. That We encounter molds everywhere in our daily lives and that significantly affects our lives. Aflatoxin comes from the name of the mold that produces it (Aspergillus flavus) and the word "toxin" meaning poison. Aflatoxins are produced mainly by the molds Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius and are highly toxic substances. Aflatoxins are dangerous and important mycotoxins that are commonly found in many foods including grains, oilseeds, spices, meat and meat products, milk and dairy products, and animal feed. Aflatoxins should not be considered harmless molds found only on foods because they can cause cancer, genetic mutation, immune suppression, and developmental disorders in the womb. They also pose a great danger to humans and animals due to their resistance to heat treatment.

Aflatoxin formation

Molds produce aflatoxins under suitable environmental conditions. Factors affecting aflatoxin production and mold growth are humidity, relative humidity, climate, temperature, harvest period and conditions, ventilation, environmental factors, storage conditions, competitive flora, and substrate concentration. Molds that can grow in the temperature range of 10-45 ºC ideally develop at 20-30 ℃ and start to produce toxins. However, various nutrients such as vitamins, minerals, amino acids, fatty acids, and energy sources are also needed for the formation of aflatoxins. In addition, it should not be forgotten that the absence of molds in the structures that we can detect with our eyes in various foods we consume in daily life does not mean that there is no aflatoxin in these foods.

In which foods is aflatoxin found?

Are the foods you consume frequently and fondly at high risk of aflatoxin contamination?

Foods at high risk of aflatoxin contamination;

● Pistachio

● Hazelnut

● Walnut

● Peanuts

● Rice

● Corn

● Wheat

● Baby food

● Milk and dairy products

● Dried foods such as figs and spices (especially red chili peppers).

Protection from aflatoxins

Early intervention is possible before the food gets moldy and goes to waste. In this case, what needs to be done is to explain to individuals the conditions of mold growth on foods and what to do. It should be known that even if the mold structure is removed by physical processes such as washing, spoon scraping, cutting, heat treatment, the danger continues after these applications. The main point to be learned is how to protect foods before they become moldy.

- Care should be taken to prevent mold contamination in stages such as harvesting the raw material of the food in the field, storage, transportation, processing, product obtaining and preservation.

- Hygiene and sanitation must be ensured correctly and adequately.

- Care should be taken to consume dried fruits and nuts that have been opened and come into contact with air in a short time, and if not, to store them in a cool, dry and dark environment.

- Care should be taken not to buy foods such as spices and nuts from places where they are sold in the open and where you are not sure of their safety.

- We should take care to take spices little by little, not to keep the spices near the stove and not to sprinkle directly from the spice rack to the food by hand. This will minimize the dangers of moisture-induced aflatoxin.

Contamination of food with aflatoxins

Did you know that more than 4.5 billion people worldwide are exposed to food contaminated with varying amounts of aflatoxins? Contamination jeopardizes food safety and public health. Aflatoxins can occur at all levels, from harvesting to processing and storage. Contamination is particularly affected by humidity and temperature conditions. Contamination of food with aflatoxins occurs in three different ways: direct, indirect and transport.

Direct contamination is caused by the growth of mycotoxin-producing molds that are visibly noticeable in foods. Contamination occurs in plant products starting from the ripening stage in the field, at harvest, during drying and mostly during storage. For peanuts and hazelnuts, toxin contamination generally starts at the drying stage of harvested products. Broken, damaged hazelnut and peanut shells allow mold mycelia to pass into the kernel inside and form mycotoxins.

Indirect contamination occurs when raw materials or food additives are contaminated with mycotoxins and used in food production. Examples of indirect contamination include the use of contaminated fruits in fruit juice and concentrates, the production of dried figs and fig paste from figs containing aflatoxin, the use of contaminated peanuts in products such as peanut butter. The spices we use to add flavor and aroma to food are often contaminated with mycotoxins.

Contamination by transport occurs when lactating dairy cows fed aflatoxin-containing feed metabolize these toxins in their bodies and pass them into milk.

What to do next to control contamination of food with aflatoxins;

1. Prevent contamination and spread of mold

2. Detoxifying contaminated products

3. Preventing aflatoxin absorption in the digestive tract after consumption of toxincontaining Foods

Ingestion and effects of aflatoxins

Aflatoxins, which are mostly taken into the human body through food, are encountered through the mouth, respiration, and skin. Aflatoxin specifically targets the liver. Early signs of hepatotoxicity include fever, decreased appetite, weakness, abdominal pain, vomiting, and hepatitis. Acute poisoning cases are exceptional and rare. Studies have revealed the harmful effects of aflatoxins on the liver, epididymis, testes, kidneys, and heart.

Aflatoxin poisoning

Aflatoxins are toxic substances with mutagenic, carcinogenic, and teratogenic effects that can cause acute and chronic poisoning. These poisonings are defined as "aflatoxicosis". Acute and chronic toxic effects caused by aflatoxins vary according to the duration of exposure, how much is consumed, and the resistance of the person. The toxicity level of aflatoxins in animals depends on multiple factors such as the species, sex, breed, age, amount of toxin ingested, and duration of exposure.

Detoxification of aflatoxins

Toxic and carcinogenic mycotoxins are present in non-negligible amounts in basic foodstuffs. It is necessary to produce and develop detoxification methods for aflatoxins that pose a danger to human health. The detoxification process should be able to remove toxins from the environment, destroy mold mycelia, leave no residual residues in food products, reduce nutritional quality, and be easy to use and economical. The method and duration of detoxification varies according to the food product and the rate of contamination. In cases where aflatoxin contamination cannot be prevented, various physical, chemical, and biological methods are used to enable detoxification. In the first step, it is an important and economical method to separate discolored, deformed, and moldy foods for physical detoxification. This method is frequently and effectively used to reduce aflatoxin, especially in peanuts. However, aflatoxin cannot be removed effectively by every detoxification process and may also cause nutritional losses. For example, methods such as heat, UV light, ionizing radiation, solvent extraction can also be used. However, the temperature levels of heat treatments such as pasteurization and sterilization applied to food products are not sufficient for aflatoxin reduction.

Aflatoxin studies

Aflatoxins were first recognized and investigated as a result of an outbreak in the UK in 1960. In the outbreak, more than 100,000 turkeys and livestock died after moldy peanuts were mixed into turkey feed. Aflatoxin studies started in our country in 1967 after toxin was detected in hazelnuts exported to Canada and not accepted. The hazelnut samples returned to our country and Aflatoxin was detected in samples that were collected from Ankara province. In 1971, high amounts of aflatoxin were detected in pistachios exported to the USA, and in 1972 in Turkish dried figs exported to Denmark. In 1987, there were problems in the export of dried figs, and in 1994 in the export of dried red pepper flakes due to aflatoxin contamination. It was stated that aflatoxin control should be carried out on these products before exported from Turkey.

Aflatoxin analysis

Mold is visible to the eye, but it is not correct to say that every mold that forms contains aflatoxin. A food does not necessarily have to be moldy to contain aflatoxin. In addition, aflatoxin cannot be distinguished by sight, laboratory tests should be performed to determine whether foods contain aflatoxin.

Legal regulations on aflatoxins

After the detection of Aflatoxins in the 1960s, many countries have set a "Maximum Limit" allowed in foods to prevent the dangers posed by mycotoxin-containing foods in health and trade areas. In Turkey, according to the Turkish Food Codex Contaminants Regulation in the Official Gazette dated 29.11.2011, the maximum limit of Aflatoxin M1 is specified for raw milk, heat-treated milk, and some dairy products.

Misconceptions

Is all cheese moldy cheese? According to studies on the conditions of moldy cheese production, it is a danger to public health that they may contain mycotoxins because mold formation is allowed to occur naturally without the use of pure culture. Therefore; please Do not eat every moldy cheese in the fridge. Are you one of those who scrape the mold off your tomato paste? What would you think if we told you that this method, which you often use in your kitchen, is not very helpful? The presence of Aspergillus flavus and Aspergillus paraciticus in tomatoes and their products, which have a soft structure in terms of texture, and the risk of toxins that can be produced by these molds is high. In other words, the dangers of molds continue after these applications. In homemade tomato paste, failure to select suitable tomatoes (tomatoes that have waited too long in the field, tomatoes that have not been harvested under suitable weather conditions, tomatoes that have been subjected to physical and biological impacts during collection and transportation), failure to ensure hygiene conditions during the production of tomato paste, failure to ensure that the containers in which the tomato paste will be stored are not completely dry, airy or inappropriate storage conditions may cause mold formation in tomato paste. Therefore, care should be taken to ensure that appropriate raw materials, hygiene, and storage conditions are provided for homemade tomato paste. Storing food by drying is a traditional method that has been used for many years. In our country, sun drying technique is frequently used for this purpose. Fruits and vegetables are ready for consumption by passing through various drying stages. However, environmental factors such as insufficient drying, inappropriate temperature, humidity, and light make dried fruits susceptible to mold contamination and mycotoxins. A common culinary truism is that dry foods don't spoil for long. However, the situation is a little different. For example, peanuts face the risk of aflatoxin in the steps from growing to preservation. Again, dried figs are a good example of these types of foods. Picking under unsafe conditions, drying under unhygienic conditions, inadequate storage conditions, and high sugar content lead to mold growth, resulting in dried figs with aflatoxin contamination.

Summary

Aflatoxin, which has been frequently mentioned in the field of food safety in our country and around the world lately and has always been on the news agenda, is one of the many chemicals produced by some of the molds that we encounter everywhere in our daily lives and which significantly affect our lives. Molds produce aflatoxin under suitable environmental conditions. When a suitable environment is created due to factors such as humidity, relative humidity, climate, temperature, harvest period and conditions, ventilation, environmental factors and storage conditions, mold and related aflatoxins form very quickly in a food. Acute and chronic toxic effects caused by aflatoxins; It varies depending on the duration of exposure, how much is consumed and the person's resistance. For this reason, it may take a long time for you to understand your exposure to aflatoxin, or it may be difficult to determine that the health problem it causes is caused by aflatoxin. Aflatoxin in foods can occur in the field, during harvest, during drying, storage, or in the milk of animals that consume feed containing aflatoxin, and in any food in which this milk is used. Exposure to aflatoxin can cause mutations, cancers and many diseases in humans. For this reason, it is extremely important to examine all stages from field to table in terms of aflatoxin and to increase consumers' awareness in this regard.