Mycotoxins: A Hidden Poison in Foods (Research Proposal Sample)

Research Proposal- Nutrition
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Mycotoxins: A hidden poison in foods
Background to the research issue
Mycotoxins are defined as poisonous chemical metabolites that are produced by filamentous fungi (Bennett & Klich, 2003). Some of the mycotoxin compounds are found in grains and seeds hence can cause diseases, disorders and even death to oblivious consumers who include human beings and animals. Mycotoxins found in food have disastrous effects often leading to severe illness or chronic long-term conditions and immune deficiency (Wild & Gong, 2010). When detected, mycotoxins cause heavy economic losses to stakeholders in the agricultural industry who include producers of food, processors, distributers and the consumers of the food.
There are five groups of mycotoxins that are found in food and these include: deoxynivalenol or nivalenol, zearalenone, ochratoxin, fumonisins and aflatoxins (Murphy et al, 2006). Of major interest are aflatoxins which are commonly found in grains such as maize and peanuts and fumonisins, both of which are common in tropical developing countries where they have a significant impact on human health.
Mycotoxins are a cause of great concern because they occur in very small quantities which therefore make them easily undetectable in foodstuffs. They are therefore hidden poisons in food with very serious repercussions to human and animal health. Most of the discussion about mycotoxins revolves around the foods that are likely to be afflicted with the fungi, its chemistry, prevention measures but the idea of the fungi being a hidden poison in food is minimally discussed.
With this background into the research issue, the main purpose of this research is to investigate how the food that human beings consume may be unknowingly poisoned and highlight the effects of the mycotoxins to human beings. The results of this research will try to identify ways of identifying mycotoxins in food to prevent illnesses and deaths among human beings and animals.
The research question
How can mycotoxins be detected in food and what are the awareness and preventive measures which can be taken to minimize casualties that arise from the consumption of food containing mycotoxins?
Justification for the proposed research
Mycotoxins in food have fatal consequences to both human beings and animals. This is particularly devastating considering that they are lethal in very small quantities normally measures in parts per billion (ppb) or parts per million (ppm). Mycotoxins naturally cause immune deficiencies and protect the filamentous fungi from attack by other microorganisms. Toxicological effects of mycotoxins have been experimentally proven in laboratories using animals and they have yielded results that have raised a reason for concern among researchers.
Aflatoxins which is a group of mycotoxins is a well identified cause of liver cancer in addition to jeopardizing immunity in laboratory and infected animals when ingested in large quantities. The toxins also compromise the metabolism of proteins and other micronutrients which are crucial for good health. According to Williams et al (2004), approximately 4.5 billion people living in developing countries are exposed to uncontrolled quantities of aflatoxin and other mycotoxins found in food. The disease burden is these countries which is more than 40% is further aggravated by the toxic effects of aflatoxin ingestion. The categorization of mycotoxins as a low priority risk factor for the increase in disease burden by the World Health Organization (WHO) makes it even more important to highlight the nutritional effects of the toxins on human and animal health.
Current technology for the detection of mycotoxins includes the use of a variety of biosensors which have undergone a series of developments to become more accurate and sensitive. The current technologies identified by Maragos (2004) used to detect mycotoxins include the following: evanescent wave technology, lateral flow devices, dipstick devices, fluorescence polarization, capillary electrophoretic immunoassays, microbead assays and time-resolved fluorescence. These technologies prove to be effective in laboratories and the challenge is therefore to make them competitive compared to other conventional techniques used in the field. The method used to detect mycotoxins is dependent on factors which include speed, accuracy, skills necessary and the cost of carrying out the method. Another challenge is to identify methods of detecting mycotoxins in a small scale and away from analytical laboratories.
The gap in existing research concerning mycotoxins is the identification of mycotoxicosis as a hidden threat that has fatal effects on the health of human beings and animals. The technologies that exist to detect mycotoxins and the fungi which cause them are expensive and are confined to analytical laboratories which are few in number. The task is to develop innovative technologies which require less labour and which are more accessible due to reduced costs. The current technologies are still unable to enable the simultaneous detection of multiple mycotoxins from the same sample. This is because the different groups of mycotoxins are made up of different chemical compositions and physical properties which is also a challenge to researchers.
The preliminary literature review section that follows looks at previous researcher’s work concerning the sources, chemistry, diseases and preventive measures for mycotoxins.
Preliminary literature review
Sources of mycotoxins
Mycotoxins are produced following the growth of fungi which mostly occurs in crops and agricultural products. However the toxins are not formed on all the crops since there are factors which facilitate the process. These include the level of exposure to infestation by fungi, the appropriateness of fungal substrate, climate, moisture content of crops and exposure to damage by pests and insects. The fungi which cause the production of mycotoxins in crops and seeds are divided into three categories: storage fungi, field fungi which attack plants and advanced deterioration fungi which attack seeds that have already been damaged and have high moisture content. Examples of storage fungi are Aspergillius flavus and Aspergillius parasiticus, those of field fungi are Fusarium tricinctum, Fusarium moniliforme, Fusarium roseus and Fusarium nivale while examples of advanced deterioration fungi include Aspergillius clavatus, Aspergillius fumigatus, Mucor, Absidia, Chaetomium, Rhizopus and Scopulariopsis (Magan & Olsen, 2004).
Chemistry of mycotoxins
Mycotoxins vary greatly in terms of chemical structures. One of the earliest mycotoxins to be identified, ergotism, is grouped as indole alkaloids which are found on the heads of plants of the grass species such as wheat. The alkaloids are produced from a system of tetracyclic ergoline ring. There are four major Aflatoxins which are B1, B2, G1 and G2 of which Aflatoxin B1, is naturally carcinogenic. Aflatoxins are derived from difuranocoumarin which are generated by polyketides by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin consumed by cows transforms the aflatoxin B1 into hydroxulated aflatoxin M1. Fumonisins are produced through the synthesis of an amino acid known as alanine through the process of condensation. The most abundant fumonisin is fumonisin B1. Trichothecenes have a common structure of 12, 13-epoxytrichothene and an olefinic bond which has different substitutions depending on different chains. These are further classified into two groups, macrocylic or nonmacrocylic depending on the ester or ester-ether bridge between C-4 and C-15. Type A of nonmacrocylic has a hydrogen side chain on the 8th carbon position while type B contains a ketone. Zearalenone is another mycotoxin which is made up of resorcylic acid lactone or lactene, a C-1 and C-2 double bond and a C-6 ketone (Murphy et al, 2006).
Foods infected by fungi that potentially deliver toxins
The foods that are prone to infection by filamentous fungi which cause mycotoxins generally consist of seeds and grains. However, fruits and vegetables are mostly affected by the fungi Rhizopus and Mucor. Seeds containing oil such as soya, maize, sunflower, groundnuts cotton seed cake and tree nuts are mostly affected by Aspergillus parasiticus, Aspergillus flavus and aflatoxins. Other foods and seeds that can be affected by mycotoxin causing fungi include coffee, rice, sweet potatoes, rice, sorghum and figs. Cows that feed on contaminated food are also known to produce milk contaminated with aflatoxin. The fusarium species of mycotoxins are known to attack plants such as corn, grasses and legumes and tomatoes.
Diseases and disorders related to poisoning from mycotoxins
Mycotoxins are known to cause various diseases in human beings and animals when food infected by filamentous fungi is ingested. Most of the mycotoxins have been identified as being carcinogenic in humans and they also cause immune deficiency. In animals, mycotoxins are known to cause complications in the reproductive system of pigs, cancer in laboratory animals, equine eucoencephalomalacia which is a serious disease in horses and adverse effects in chickens.
The major outbreaks of mycotoxins include the death of thousands of people in the UCSSR during the 1940s due to alimentary toxic aleukia, stachybotryotoxicosis which claimed the lives of thousands of cattle and horses in the same country in the 1930s and 100,000 turkeys that died in England due to aflatoxicosis (Semple et al, 2011). More recent outbreaks as documented by Schmale and Munkvold (2009) include the death of more than 75 dogs in the United States following the consumption of dog food that contained aflatoxins. Several other dogs in their hundreds suffered liver damage due to expo...