Portable biosensor: Making food, feeds safe from toxins (Daily Monitor (Uganda))

The presence of aflatoxins in food and feed are a major reason why some of our agricultural produce would be rejected in international markets. In addition, they are harmful to both human and animal health. They can cause diseases like cancer and nervous and reproductive disorders, retard growth in children, and even death when consumed.
But what are aflatoxins? These are poisons excreted into food or feed by fungi when they grow in it. Fungi do not want competition from other germs, so they make and deploy poison where they grow to inhibit or kill competitors.

Accurately detect
To counter this challenge, an aflatoxin-detection tool has been developed by a group of Ugandan scientists Joseph Fuuna Hawumba, Peter Vuzi and Deborah Wendiro.
Hawumba and Vuzi are biochemistry professors from Makerere University, while Wendiro heads Microbiology and Biotechnology department at Uganda Industrial Research Institute (UIRI).
Known as Portable Electrochemical Biosensor (Peb), it is a simple tool designed to accurately indicate any slight presence of aflatoxins. It electronically registers and displays results on a screen (like a mobile phone) within a few minutes after the testing.

Peb is portable, which means that one carry it and use it there at the point of need. “I got inspiration to save farmers the need to travel long distances to Kampala to test their products to demonstrate safety from aflatoxins before they can access markets,” says Paul Alex Wacoo, a biochemist at UIRI, who was involved in the development of Peb.
“It was not an easy thing balancing between ranges of globally available options to select locally-appropriate substitutes there were many good accessories I would choose but they were not obtainable. We succeeded to make this one,” says Mathew Ocheng, a hardware engineer who designed the electronic relay system.
He joined Wacoo where the science of biochemistry meets electronics engineering and socio-economic necessity.

First of a kind
Peb has been validated against globally recognised tools and proved suitable for field use, and complies with food safety standards set by the Food and Agriculture Organisation (FAO).
A first of this kind innovation on the world market, Peb is 100 per cent effective in detecting presence of aflatoxins in food crops, food products and feeds. It is not useful, however, as a prototype on a shelf at UIRI.
Prof Hawumba, notes that it is handy and can be applied by anyone. It is especially relevant to farmers, produce-dealers, food quality-regulators, public health inspectors, local traders, exporters, processors, and consumers.

Special focus
“Mycotoxins develop as a result of fungal infection to produce when it either does not dry properly or is stored in dumpy conditions,” adds Wendiro.
“Fungal contamination can occur through birds, animals, human beings or other agents, causing damage to unharvested produce while it is in the fields.”
National Agricultural Research Organization (Naro) in collaboration with Makerere University, have carried out research on aflatoxin-contamination in cereals and legumes and grainswith special focus on groundnuts.

Enforce measures
The recommendations were that to reduce the hazards, the government should establish sensitisation and training programmes for farmers, traders and consumers on good pre- and post-harvest management.
This should be through ministries of health and agriculture, together with UIRI and Uganda National Bureau of Standards.
The regulations for monitoring produce from buying points to retail markets should be in place. As well, measures on the quality of food should be enforced by appropriate agencies. This makes Peb a valuable technology in post-harvest management.

What are aflatoxins?

So how big is the aflatoxin threat? Aflatoxin is a life-threatening and very rampant phenomenon in Uganda, East Africa, Africa and other countries where maize (or corn), groundnuts and other cereals are eaten.
In their 2010 study titled “Management of Aflatoxin in Groundnuts: A Manual for Farmers, Processors, Traders and Consumers in Uganda”, the researchers David K. Okello, Archileo N. Kaaya, Jenipher Bisikwa, Moreen Were and Herbert K. Oloka, state that aflatoxins are not visible neither do they have a particular flavour. They add that it is not easy to convince consumers about their existence in food.

The majority of farmers, traders and consumers in Uganda are not aware of the aflatoxin risk on commerce, human and livestock health yet contamination can occur in the field. This is during post-harvest drying, storage as well as shipment.
UN’s Food and Agricultural Organisation (FAO) estimates that 25 per cent of the world’s crops are affected by mycotoxinsthe most notorious of which are aflatoxins.
Losses to livestock and poultry producers from aflatoxin-contaminated feeds include the effects of immune system suppression, reduced growth rates, and losses in feed efficiency. Other adverse economic effects include lower yields for food and fibre crops. The problem has been reported to be more serious in tropical and sub-tropical regions of the world where climatic conditions (temperature and relative humidity) favour the growth of Aspergillus species of fungi.




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