Aflatoxin Poisoning causes DNA damage and with prolonged exposure to aflatoxin, cells accumulate DNA mutations. And thus are at increased risk of developing into cancer cells. Therefore, Aflatoxin, a byproduct of molds, is a potent cancer-causing agent, especially, liver cancer.
Aflatoxicosis is a condition that results from eating food contaminated with Aflatoxins, which are toxins produced by fungi such as Aspergillus flavus. In the short term, aflatoxin poisoning may cause nausea, vomiting, and abdominal pain. Convulsions. Pulmonary edema, which is fluid buildup in the lungs.
The aflatoxin producing fungi, Aspergillus spp., is widely-spread-in-nature. And have severely contaminated food supplies of humans and animals. Resulting in health hazards and even death. Therefore, there is a great demand for aflatoxins research to develop suitable methods for their quantification, precise detection, and control to ensure the safety of consumers’ health.
Aflatoxins are one of the highly toxic secondary metabolites derived from polyketides produced by fungal species such as Aspergillus flavus, A. parasiticus, and A. nomius (Payne and Brown, 1998).
These fungi usually infect cereal crops including wheat, walnut, corn, cotton, peanuts and tree nuts (Jelinek et al., 1989; Severns et al., 2003). And can lead to serious threats to human and animal health by causing various complications such as hepatotoxicity, teratogenicity, and immunotoxicity.
What are Major Sources of Aflatoxins?
The major sources of aflatoxins are fungi such as A. flavus, A. parasiticus, and A. nomius (Kurtzman et al., 1987). As well as by Emericella spp. (Reiter et al., 2009). There are more than 20 known aflatoxins. But, the four main ones are aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2); Inan et al., 2007).
While aflatoxin M1 (AFM1) and M2 (AFM2) are the hydroxylated metabolites of AFB1 and AFB2 (Giray et al., 2007; Hussain and Anwar, 2008). The Aspergillus species are an industrially important group of microorganisms distributed worldwide.
A. niger has been given Generally Recognized as Safe (GRAS) status by the USFDA (Schuster et al., 2002). However, some species have negative impacts and cause diseases in grape, onion, garlic, peanut, maize, coffee, and other fruits and vegetables (Lorbeer et al., 2000; Magnoli et al., 2006; Waller et al., 2007; Rooney-Latham et al., 2008).
Which are the general Types of Aflatoxin?
Aflatoxin mycotoxins are produced by the Aspergillus species of molds. Aspergillus molds grow mostly on crops, such as grains and nuts.
Under the right conditions, Aspergillus often grows on grain before it is harvested. But it can also grow on harvested grain if the grain is stored damp.
Aspergillus also grows on substances like soil, hay and decaying vegetation. The best conditions for Aspergillus to grow on organic materials are when the temperature is warm and when the material has a high level of moisture (7% or more).
There are three main types of aflatoxin mycotoxins:
- Aflatoxins B: This group includes aflatoxin B1 and B2. Aflatoxin B1 is the most common aflatoxin, as well as the most toxic and carcinogenic.
- Aflatoxins G: This group includes aflatoxin G1 and aflatoxin G2
- Aflatoxins M: This group includes aflatoxins M1 and M2. These aflatoxins are metabolic products that are found in the urine and milk produced by animals that have been given a feed with aflatoxins in it.
How harmful is Aflatoxin Poisoning?
The technical term for poisoning by aflatoxin mycotoxins is aflatoxicosis. This usually occurs from eating food contaminated with aflatoxin mycotoxins. Aflatoxicosis is not contagious and drugs and antibiotics do little to help. Aflatoxicosis damages the liver more than any other organ.
Aflatoxin mycotoxins also suppress the immune system, and therefore, are toxic to humans and even more toxic to animals. They also cause cancer in humans and animals. Basically, eating vegetables like carrots and celery reduces the carcinogenic effects of aflatoxins.
The aflatoxin LD50 rate (the dosage level that causes 50% of a group to die) for animals is between 0.5 and 10 mg/kg of the animal’s weight. Among the mycotoxins affecting food and feed, aflatoxin is the major one in food. That ultimately harms human and animal health (Boutrif, 1998).
The level of toxicity associated with aflatoxin varies with the types present, with the order of toxicity being AFTs-B1 > AFTs-G1 > AFTs-B2 > AFTs-G2 (Jaimez et al., 2000). Read more about How Ghana Intensifies Bid for Eradication of Aflatoxins.
What are the Symptoms of Aflatoxin Poisoning?
How badly a person is affected by aflatoxin mycotoxins depends on a variety of things. Like the person’s age, gender, level of exposure, duration of exposure, health, the strength of their immune system, diet and environmental factors.
There are two main ways people are usually exposed to aflatoxins. The first is when someone takes in a high amount of aflatoxins in a very short time. This can cause:
- Liver damage
- Liver cancer
- Mental impairment
- Abdominal Pain
- Pulmonary Edema
- Disruption of food digestion, absorption or metabolism
The other way people suffer aflatoxin poisoning is by taking in small amounts of aflatoxins at a time but over a long period. This might happen if a person’s diet has a small number of aflatoxins, for example. When this happens it can cause:
- Growth and development impairment
- Liver cancer due to DNA mutation caused by aflatoxins
How does Aflatoxin Poisoning occur in Food?
The American Food and Agriculture Organization (FAO) estimated an average of 25% of the food crops in the world that are affected by mycotoxins. Of these mycotoxins, aflatoxins are the biggest problem.
As an example, some of the topmost aflatoxin contamination prone crops include corn, cottonseed, and peanuts. Aspergillus also commonly grows on beans, rice, tree nuts, and wheat. It grows less often on other grains and nuts.
Aflatoxin mycotoxins can end up in milk, eggs, and even meat if animals are fed with contaminated plants. Aflatoxin M1 and M, which are often found in cow’s milk, are metabolites produced by animals that have eaten aflatoxins.
How do you Determine the Level of Aflatoxin Poisoning?
Aflatoxins are found all over the world. However, they are much more of a problem in undeveloped or developing nations than they are in developed countries.
Developed countries prohibit high levels of aflatoxin mycotoxins in foods. For example, the United States limits the level of aflatoxins to under 20 parts per billion in food and specifies that the aflatoxins M must be below 0.5 parts per billion in milk.
A chemical process is used to remove aflatoxins in foods such as nuts, corn, grains, and milk. Most foods do still contain very small amounts of aflatoxins though. Although the aflatoxin levels are usually far below the safety limits, this has raised a concern about the effects on humans of the long term intake of small amounts of aflatoxins.
Pets have died from eating pet foods contaminated with aflatoxin mycotoxins. Between late 2005 and early 2006, 23 or more dogs died from eating Diamond Pet Foods dog food contaminated with aflatoxins.
Major Outbreaks of Aflatoxins Worldwide
Food safety is one of the major problems currently facing the world. Accordingly, a variety of studies have been conducted to discuss methods of addressing consumer concerns with various aspects of food safety (Nielsen et al., 2009).
Since 1985, the United States Food and Drug Administration (USFDA) has restricted the number of mycotoxins permitted in food products. The USDA Grain and Plant Inspection Service (GPIS) have implemented a service laboratory for inspection of mycotoxins in grains.
Additionally, the Food and Agricultural Organization (FAO) and the World Health Organization (WHO) have recognized many toxins present in agricultural products.
Here are are the notable cases related to aflatoxin poisoning;
1. Hepatitis cases in India
In 1974, a major outbreak of hepatitis due to aflatoxin was reported in the states of Gujrat and Rajasthan in India, resulting in an estimated 106 deaths (Krishnamachari et al., 1975).
The outbreak lasted for 2 months. With the majority of confirmations being from the tribal people (staple food being maize). The preliminary analysis confirmed that consumption of A. flavus had occurred (Krishnamachari et al., 1975; Bhatt and Krishnamachari, 1978).
2. Aflatoxin outbreak in Kenya
A major aflatoxin exposure outbreak was subsequently documented in Kenya in 1981 (Ngindu et al., 1982). Since 2004, multiple aflatoxicosis outbreaks have been reported worldwide. Resulting in 500 acute illnesses and 200 deaths. According to, Centers for Disease Control and Prevention [CDCP], 2004; Azziz-Baumgartner et al., 2005.
Additionally, in Kenya, the majority of confirmations being from the East Province region in 2004. And occurred because of the consumption of homegrown maize contaminated with molds. Preliminary testing of food from affected areas revealed the presence of aflatoxin as reported in 1981 (Ngindu et al., 1982).
3. Aflatoxin outbreak in Europe
In 2013, countries in Europe including Romania, Serbia, and Croatia reported the nationwide contamination of milk with aflatoxin.
How do you control Aflatoxin levels?
High aflatoxin levels depress the immune system of the human body. Thereby contributing to many health problems ranging from cancer and susceptibility to HIV, to stunted growth among children. This led governments in Africa to band together to stop the spread of Aflatoxins in the continent.
For instance, at an October 2016 meeting with the Partnership for Aflatoxin Control in Africa (PACA), Ugandan President, H.E. Yoweri Museveni called for a collective effort. Especially, among African countries to address aflatoxin challenges.
However, improved post-harvest handling remains the most overlooked component for effectively preventing aflatoxin growth. In hot, humid climates, long-term conventional storage can cause exponential growth of aflatoxins. It shows that restricting the increase in aflatoxin levels during both drying and storage is a major challenge, particularly under hot and humid conditions.
How do you Control the Rate of Aflatoxin Poisoning?
Notably, according to PACA, there are best methods known for controlling Aflatoxins through improved Post-harvest Practices. An increasingly popular and inexpensive alternative method for controlling aflatoxin growth during months-long storage is using flexible, Ultra Hermetic Storage Containers.
This storage technology relies on creating suitable conditions to prevent the increase of aflatoxin levels. For the successful application of Ultra Hermetic Storage Systems, as well as for other storage methods, crops must be adequately dried. Typically to a point below their critical moisture level (in equilibrium with 65% relative humidity).
This paper examines the prevention of aflatoxin growth occurring in multi-month, post-harvest storage in tropical countries, with examples from field experience and scientific data. By creating an unbreathable atmosphere (low oxygen, high carbon dioxide) through insect and microorganism respiration alone. Not to mention, without the use of chemicals, fumigants, vacuum, or refrigeration.
What is Hermetic Storage?
Sealed or hermetic storage systems are a very effective means of controlling grain moisture content and insect activity for grain stored in tropical regions.
By placing an airtight barrier between the grain and the outside atmosphere the moisture content of the stored grain will remain the same as when the storage was sealed.
As a matter of fact, the biological activities inside the sealed container will consume oxygen. And as a result, most insects will die. Hermetic storage provides moisture and insect control without pesticides.
Which are the Main Types of Hermetic Systems?
The size of hermetic storages can range from 3 liters to 2,000 tons. For your information, below is a video on How does hermetic storage work?
There are various main types of Hermetic storage made from PVC materials. But, the main ones include;
- Cocoon™– commercially available
- the GrainSafe™
- the smaller 50kg IRRI Super bags – available to farmers and processors at low cost
- locally available containers – useful in rural settings, where local containers can be easily converted into hermetic storage systems
Normal cooking doesn’t destroy Mycotoxin’s contaminated food. However, there have been many recent advances in food processing. Particularly, developed to keep final food products safe and healthy.
Moreover, several physicals, chemical and biological methods can be applied. To partially or completely eliminate these toxins from food. And guarantee the food safety and health concerns of consumers.
Moreover, the effects of processing techniques on aflatoxins and various physical, chemical and biological methods for their control and management in food are discussed briefly here.
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