Mycotoxins Contamination of Food in Somalia

Introduction A paper was recently published in the American Chemical Society (ACS) Journal of Agricultural and Food Chemistry (JAFC) by scientists from the Queens University, Belfast, Northern Ireland, UK, and their collaborators. A total of 140 samples (42 maize, 40 sorghum, and 58 wheat) were collected from a number of markets in Mogadishu, Somalia, and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) multi-mycotoxin method that could detect 77 toxins. All of the maize samples tested contained eight or more mycotoxins, with aflatoxin B1 (AFB1) and fumonisin B1 (FB1) levels reaching up to 908 and 17 322 μg/kg, respectively, greatly exceeding the European Union (EU) and the USA allowed limits and guidance values for these toxins. This write up is intended to bring to the attention of the Somali Government and Somali Community at large the serious nature of the risks presented by the issue of contamination of food and animal feed with toxins, at levels well beyond the limits set by advanced industrialized countries as well as international organizations such the World Health Organization (WHO). This review will: 1. Discuss the salient points of this recent paper on mycotoxin contamination of food in Somalia and the serious implications and impacts of this on the health and economic well-being of the people of Somalia. 2. Explain, in layman’s terms, what are mycotoxins. 3. Briefly discuss severe health risks they pose to both human and animal populations; 4. Explain how they are tested and detected, with emphasis on simple and cheap filed tests that can be performed by people who do not have laboratory training; 5. Methods of lowering mycotoxin concentrations in food and animal feed; 6. Look at new environmentally safe technologies that have been developed to combat mycotoxins. 7. Finally, summarize some of the world-wide organizations that can provide both research expertise and funding, with especial emphasis on those focused in Africa, particularly the African organizations and research centers and their collaborators who are engaged in fighting this serious problem will be listed. 1. Human-Health Impacts of Mycotoxins in Somalia [1] Mycotoxins are chemically diverse secondary metabolites that can contaminate food commodities in the field and during storage, transportation, and food processing, impacting both human and animal health. Susceptibility of cereals to mycotoxin contamination, particularly aflatoxins (AFs), fumonisins (FUMs), and deoxynivalenol (DON), have been widely described. Apart from acute toxicosis, chronic exposure to AFs has been associated with carcinogenicity, particularly in conjunction with chronic hepatitis B virus (HBV) infection. Governmental and international institutions have thus set specific mycotoxin regulations and established maximum tolerated levels of mycotoxins in foodstuffs. Somalia had a turbulent recent history with a civil war followed by violent domestic conflicts and had no strong central government since 1991. Consequently, the problem of food safety has not been addressed. As such, there are no regulations in place, and there is very little information regarding mycotoxin occurrence in food and the resulting exposure of the Somali population. The only available report on mycotoxin concentrations in maize focuses on AFB1, fumonisin B1 (FB1), and DON only, which were assessed via enzyme-linked immunosorbent assay (ELISA) (see reference 1). The goal of this study was to assess multi-mycotoxin occurrence in staple foods for the first time in Somalia. Generated data was employed to assess the possible impact of exposure to aflatoxins and fumonisins and could be used to assess the impact of other mycotoxins on the health of the Somali population. The researchers of this study hope its conclusions encourage further research and bolster initiatives in the region aimed at providing safe food to the people of Somalia. a) Sampling method: A market survey of three Somali staple foods (i.e., maize, sorghum, and wheat) was performed utilizing a multi-analyte liquid chromatography-tandem mass spectrometry (LCMS/ MS) approach. Approximately 80% of domestic cereal output in Somalia comes from the Bay, Bakool, and Lower and Middle Shabelle regions around the larger inter-riverine area between the Shabelle and Juba river valleys of southern Somalia. A set of 140 samples, which included 42 maize samples (21 white and 21 yellow), 40 sorghum samples (20 white and 20 red), and 58 wheat samples (25 locally grown and 33 imported), were collected from different local markets in Mogadishu, Somalia, between October 2014 and February 2015. Because the aim of the study was to perform a market survey to reflect real exposure of the Somali consumers living in Mogadishu, samples of 1 kg were bought from local retailers and shipped to the United Kingdom. All samples were stored in a dark and dry place at 4 °C until their analysis. b) Sample Analysis: Sample extraction and analysis were performed using a previously validated multi-mycotoxin LC-MS/MS method (for details see reference 1). c) Point Estimates of Dietary Exposure: In the present study, a deterministic model based on average consumers’ exposure was applied as this was deemed to be the most relevant for long-term exposure assessments by both the World Health Organization (WHO) and the European Food Safety Authority (EFSA). As an estimation, the degree of mean dietary exposure was expressed as the average probable daily intake (APDI) for maize. Because there is no nationwide data on demographic characteristics, maize-consumption patterns in the Somali population relied on data available for neighboring countries (a conservative approach). The average food consumption was based on the data available for Kenya and Ethiopia, adapted from Food and Agricultural Organization Statistical data (FAOSTAT) food-balance sheets quoting 163 g per person per day for maize. Also, no data on average body weight is available for the Somali population; thus, an assumed body weight of 60 kg was used as outlined by the WHO. The APDI of each mycotoxin was calculated according to the following equation: APDI = (C × K)/bw where APDI is the average probable daily intake (ng/(kg bw)/day) for each mycotoxin, C is the mean concentration of a mycotoxin in the food (ng/ g), K is the average consumption of maize (g/person/day), and bw is the assumed body weight of 60 kg. d) Characterization of Risks from Consumption of Contaminated Grains: The Margin-of-Exposure Assessment method of the Joint FAO/WHO Expert Committee on Food Additives (JECFA) (WHO) and the Scientific Panel on Contaminants in the Food Chain (CONTAM Panel) of the EFSA was followed. It recommends the application of the margin of exposure (MOE) for risk characterization and an indication of the level of health concern of substances that are both genotoxic and carcinogenic, such as AFs. The magnitude of the MOE gives an indication of the risk level (i.e., the smaller the MOE, the higher the potential risk posed by exposure to the compound of concern), with MOEs of 10, 000 or higher (based on an animal study) being of low concern for public health. To assess the aflatoxin-related liver-cancer burden due to the consumption of contaminated grains, AFB1 was used as it is the major proportion of total aflatoxins in the analyzed samples and its ingestion is directly linked to the development of liver cancer. The associated risk was characterized by estimating liver-cancer rates for average staple-grain consumers and expressed as the number of cancers per 100 000 people per year. e) Results: All the maize samples and 18% of the sorghum samples exceeded the EC maximum limits for AFB1 (2 μg/kg) and for total aflatoxins (4 μg/kg) in cereals. Levels of contamination up to 454 and 270 times the EU maximum limits for AFB1 and total aflatoxins, respectively, were found in maize samples. Levels of AFB1 in sorghum samples exceeded EU maximum limits by up to 52 times. Comparing different types of maize and sorghum, the levels of mycotoxins were lower in yellow maize and in white sorghum compared within white maize and red sorghum. Such extreme high concentrations of aflatoxins in maize may have severe health implications for the consumers, considering the daily consumption of maize in Somalia. FUMs contaminated 100% of maize samples and 38% sorghum samples. FB1, the most prevalent and most toxic fumonisin, which has been classified as a group 2B possible human carcinogen contaminated all maize samples with concentration levels in the range of 843?17,322 and 1601? 8113 μg/kg for white and yellow maize, respectively. In addition, 75% of whitesorghum samples were found to contain FB1 at concentration levels ranging from 13.5 to 160 μg/kg. The APDIs of AFG1 and AFG2 for yellow maize were 11.4 and 23.6 ng/(kg bw)/day, respectively. For total aflatoxins (AFB1, AFB2, AFG1, and AFG2), the APDIs were 1614 and 649 ng/(kg bw)/day for white and yellow maize, respectively. For the comparative purpose of this study, the estimated APDI for aflatoxins was compared with those from other continents as well as with those from countries within Africa. The exposure to total AFs for the Somali population was substantially higher than the estimated mean exposures to aflatoxins of populations in Europe (0.93?2.4 ng/(kg BW)/day), the United States (2.7 ng/(kg BW)/day), Asia (53 ng/(kg BW)/ day), and Africa (1.4?850 ng/(kg BW)/day). AFB1 has been shown to be a potent liver carcinogen, causing hepatocellular carcinoma (HCC) in humans and a variety of animal species. Liver cancer is the third leading cause of cancer deaths in the world, with the highest rates in Africa and East and Southeast Asia. The prevalence of HCC is 16-32 times higher in developing countries than in developed countries. More than a quarter of the 550,000?600,000 new HCC cases reported worldwide each year may be attributable to AF exposure. Other studies have evaluated the relationship between the incidence of HCC and human exposure to aflatoxins in a number of African countries, including Kenya, Mozambique, and Swaziland. With average dietary AFB1 exposure estimated at APDIs of 1402 and 584 ng/(kg BW)/day through the consumption of white and yellow maize, respectively, Somali individuals are at high risk of developing primary liver cancer. The levels of FUM exposure were also estimated in the maize samples analyzed. To assess the risk resulting from dietary exposure to FUMs in maize, the APIs were compared with provisional-maximum-tolerable-daily-intake (PMTDI) values, for which exceedance indicates the potential for health risks. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends a PMTDI of 2 μg/(kg BW)/day for FB1 and FB2 separately or combined. The average APIs for FB1 in the Somali population was 11.89 and 10.77 μg/(kg BW)/day for white maize and yellow maize, respectively, representing 595 and 539% of the PMTDI. Total fumonisins (FB1 and FB2) that the Somali population was exposed to were 16.70 and 13.89 μg/(kg bw)/day from white-maize and yellow maize consumption, respectively, representing 835 and 694% of the PMTDI. These high exceedances of the PMTDI indicate potential health risks from fumonisin dietary exposure. Exposure to high fumonisin levels through the consumption of contaminated maize has been associated with the risk of developing liver lesions, which was observed in experimental animals, and

tionally, toxigenic fungi contaminating agricultural grains have been conventionally divided into two groups those invade seed crops have been described as “field” fungi (e.g., Cladosporium, Fusarium, Alternaria spp.), which reputedly gain access to seeds during plant development, and “storage” fungi, (e.g., Aspergillus; Penicillium spp.), which proliferate during storage [4]. Currently, this division is not so strict because according to Miller [6] four types of toxigenic fungi can be distinguished: (2) Plant pathogens as Fusarium graminearum and Alternaria alternata; (3) Fungi that grow and produce mycotoxins on senescent or stressed plants, e.g., F. moniliforme and Aspergillus flavus; (4) Fungi that initially colonize the plant and increase the feedstock’s susceptibility to contamination after harvesting, e.g., A. flavus; (5) Fungi that are found on the soil or decaying plant material that occur on the developing kernels in the field and later proliferate in storage if conditions permit, e.g., P. verrucosum and A. ochraceous. The involvement of Aspergillus spp. as plant pathogens have been reported and aflatoxin-infected crops have from time to time been returned to agricultural soils. This practice may prove hazardous since both A. flavus and A. parasiticus can infect crops prior to harvesting [7]. The phytotoxic effects of the aflatoxins have been investigated, with respect to seed germination, and the inhibition of root and hypocotyl elongation [8, 9]. Aflatoxin has been reported to occur within apparently healthy, intact seeds which suggest that the toxin can he transported from contaminated soil to the fruit [10]. Aflatoxin B1 (AFB1) can be translocated from the roots to the stems and leaves. If the soil microorganisms do not rapidly degrade the aflatoxin contained within the plowed under stover and grains, the possibility that the roots of the seedlings of the following year’s crop will both absorb and translocate the aflatoxins to both the stems and leaves exists [11]. This could be hazardous to the plant’s growth and development as well as to the consumer’s health. Fungal growth a. Field fungi: fungi that attack plants that grow in the field (occurring prior to harvest) grow under special conditions. (Fusarium) b. Storage fungi: Storage fungi usually invade grain or seed during storage and are generally not present in large quantities before harvest in the field. The most common storage fungi are species of Aspergillus and Penicillium. Contamination occurs through spores contaminating the grain as it is going into storage from the harvest. The development of fungi is influenced by the: ? Moisture content of the stored grain ? Temperature ? Condition of the grain going into storage ? Length of time the is grain stored and ? Amount of insect and mite activity in the grain Among the different type of mycotoxins, aflatoxins (AFs) are widespread in major food crops such as maize, groundnuts, tree nuts, and dried fruits and spices as well as milk and meat products [12]. When animal feeds are infected with AF-producing fungi, AFs are introduced into the animal source food chain. AFs are toxic metabolites produced via a polyketide pathway by various species and by unnamed strains of Aspergillus section Flavi, which includes A. flavus, A. parasiticus, A. parvisclerotegenus, A. minisclerotigenes [13], Strain SBG [14], and less commonly A. nomius [15]. Normally, A. flavus produces only B-type aflatoxins, whereas the other Aspergillus species produce both B- and G-type aflatoxins [16]. The relative proportions and level of AF contamination depend on Aspergillus species, growing and storage conditions, and additional factors [17]. For instance, genotype, water or heat stress, soil conditions, moisture deficit, and insect infestations are influential in determining the frequency and severity of contamination [18]. For M-type aflatoxins, these compounds are normally not found on crops, but their metabolites are found in both the meat and milk of animals whose feedstuffs have been contaminated by AF-B1 and AF-B2 [12]. Susceptibility of cereals to mycotoxin contamination, particularly aflatoxins (AFs), fumonisins (FUMs), and deoxynivalenol (DON), have been widely described, and the high occurrence in Africa has been reported. Consequently, the Sub-Sahara Africa (SSA) region has suffered from many mycotoxin-poisoning incidences, some resulting in fatalities associated with acute exposure to AFs and FUMs. 3. Health Risks of Mycotoxins in Food and Animal Feed Recently, emphasis on the health risks associated with consumption of AFs in food and feedstuffs has increased considerably. As a result of this, many experimental, clinical, and epidemiological studies have been conducted showing adverse health effects in humans and animals exposed to AFs contamination, depending on exposure. High dose exposure of the contaminant can result in vomiting, abdominal pain, and even possible death, while small quantities of chronic exposure may lead to liver cancer [20]. The International Agency for Research on Cancer (IARC) has classified both B- and G-type aflatoxins as Group 1 mutagens, whereas AF-M1 is classified in Group 2B (IARC, 2015). Furthermore, AFs may contribute to alter and impair child growth. Together with other mycotoxins, AFs are commonly suspected to play a role in the development of edema in malnourished people as well as in the pathogenesis of kwashiorkor (also known as “edematous malnutrition” because of its association with edema (fluid retention), is a nutritional disorder most often seen in regions experiencing famine. It is a form of malnutrition caused by a lack of protein in the diet) in malnourished children. Moreover, AF contamination negatively impacts crop and animal production leading not only to natural resource waste, but also decreased market value that causes significant economic losses. Due to these effects, different countries and some international organizations have established strict regulations in order to control AF contamination in food and feeds and also to prohibit trade of contaminated products [22]. The regulations on “acceptable health risk” usually depend on a country’s level of economic development, the extent of consumption of high-risk crops, and the susceptibility to contamination of crops to be regulated [23]. Indeed, the established safe limit of AFs for human consumption ranges 4-30 μg/kg. The EU has set the strictest standards, which establishes that any product for direct human consumption cannot be marketed with a concentration of AF-B1 and total AFs greater than 2 μg/kg and 4 μg/kg, respectively [24, 25]. Likewise, US regulations have specified the maximum acceptable limit for AFs at 20 μg/kg. However, if the EU aflatoxin standard is adopted worldwide, lower-income countries such as those in Asia and Sub-Saharan Africa (SSA) will face both economic losses and additional The involvement of Aspergillus spp. as plant pathogens has been reported and aflatoxin-infected crops have from time to time been returned to agricultural soils. This practice may prove hazardous since both A. flavus and A. parasiticus can infect crops prior to harvesting [7]. The phytotoxic effects of the aflatoxins have been investigated, with respect to seed germination, and the inhibition of root and hypocotyl elongation [8, 9]. Aflatoxin has been reported to occur within apparently healthy, intact seeds which suggest that the toxin can he transported from contaminated soil to the fruit [10]. Aflatoxin B1 (AFB1) can be translocated from the roots to the stems and leaves. If the soil microorganisms do not rapidly degrade the aflatoxin contained within the plowed under stover and grains, the possibility that the roots of the seedlings of the following year’s crop will both absorb and translocate the aflatoxins to both the stems and leaves exists [11]. This could be hazardous to the plant’s growth and development as well as to the consumer’s health. Fungal growth a. Field fungi: fungi that attack plants that grow in the field (occurring prior to harvest) grow under special conditions. (Fusarium) b. Storage fungi: Storage fungi usually invade grain or seed during storage and are generally not present in large quantities before harvest in the field. The most common storage fungi are species of Aspergillus and Penicillium. Contamination occurs through spores contaminating the grain as it is going into storage from the harvest. The development of fungi is influenced by the: ? Moisture content of the stored grain ? Temperature ? Condition of the grain going into storage ? Length of time the is grain stored and ? Amount of insect and mite activity in the grain Among the different type of mycotoxins, aflatoxins (AFs) are widespread in major food crops such as maize, groundnuts, tree nuts, and dried fruits and spices as well as milk and meat products [12]. When animal feeds are infected with AF-producing fungi, AFs are introduced into animal source food chain. AFs are toxic metabolites produced via a polyketide pathway by various species and by unnamed strains of Aspergillus section Flavi, which includes A. flavus, A. parasiticus, A. parvisclerotegenus, A. minisclerotigenes [13], Strain SBG [14], and less commonly A. nomius [15]. Normally, A. flavus produces only B-type aflatoxins, whereas the other Aspergillus species produce both B- and G-type aflatoxins [16]. The relative proportions and level of AF contamination depends on Aspergillus species, growing and storage conditions, and additional factors [17]. For instance, genotype, water or heat stress, soil conditions, moisture deficit, and insect infestations are influential in determining the frequency and severity of contamination [18]. For M-type aflatoxins, these compounds are normally not found on crops, but their metabolites are found in both the meat and milk of animals whose feedstuffs have been contaminated by AF-B1 and AF-B2 [12]. Susceptibility of cereals to mycotoxin contamination, particularly aflatoxins (AFs), fumonisins (FUMs), and deoxynivalenol (DON), have been widely described, and the high occurrence in Africa has been reported. Consequently, the Sub-Sahara Africa (SSA) region has suffered from many mycotoxin-poisoning incidences, some resulting in fatalities associated with acute exposure to AFs and FUMs. 3. Health Risks of Mycotoxins in Food and Animal Feed Recently, emphasis on the health risks associated with consumption of AFs in food and feedstuffs has increased considerably. As a result of this, many experimental, clinical, and epidemiological studies have been conducted showing adverse health effects in humans and animals exposed to AFs contamination, depending on exposure. Highdose exposure of the contaminant can result in vomiting, abdominal pain, and even possible death, while small quantities of chronic exposure may lead to liver cancer [20]. The International Agency for Research on Cancer (IARC) has classified both B- and Gtype aflatoxins as Group 1 mutagens, whereas AF-M1 is classified in Group 2B (IARC, 2015). Furthermore, AFs may contribute to alter and impair child growth. Together with other mycotoxins, AFs are commonly suspected to play a role in development of edema in malnourished people as well as in the pathogenesis of kwashiorkor (also known as “edematous malnutrition” because of its association with edema (fluid retention), is a nutritional disorder most often seen in regions experiencing famine. It is a form of malnutrition caused by a lack of protein in the diet) in malnourished children. Moreover, AF contamination negatively impacts crop and animal production leading not only to natural resource waste, but also decreased market value that causes significant economic losses. Due to these effects, different countries and some international organizations have established strict regulations in order to control AF contamination in food and feeds and also to prohibit trade of contaminated products [22]. The regulations on “acceptable health risk” usually depend on a country’s level of economic development, extent of consumption of high-risk crops, and the susceptibility to contamination of crops to be regulated [23]. Indeed, the established safe limit of AFs for human consumption ranges 4-30 μg/kg. The EU has set the strictest standards, which establishes that any product for direct human consumption cannot be marketed with a concentration of AF-B1 and total AFs greater than 2 μg/kg and 4 μg/kg, respectively [24, 25]. Likewise, US regulations have specified the maximum acceptable limit for AFs at 20 μg/kg. However, if the EU aflatoxin standard is adopted worldwide, lower income countries such as those in Asia and Sub-Saharan Africa (SSA) will face both economic losses and additional costs related to meeting those standards. This situation requires alternative technologies at pre- and post-harvest levels aimed to minimize contamination of commercial foods and feeds, at least to ensure that AF levels remain below safe limits. 4. Mycotoxin detection technologies Analytical methods for mycotoxins in cereals and cereal-based products require three major steps, including extraction, clean-up (to eliminate interferences from the extract and concentrate the analyte), and detection/determination of the toxin (by using suitable analytical instruments/technologies). Clean-up is essential for the analysis of mycotoxins at trace levels, and involves the use of solid phase extraction and multifunctional or immune-affinity columns. Different chromatographic methods are commonly used for quantitative determination of mycotoxins, including gaschromatography (GC) coupled with electron capture, flame ionization or mass spectrometry (MS) detectors and high-performance liquid chromatography (HPLC) coupled with ultraviolet, diode array, fluorescence or MS detectors. The choice of method depends on the matrix and the mycotoxin to be analyzed. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is spreading rapidly as a promising technique for simultaneous screening, identification and quantitative determination of a large number of mycotoxins. In addition, commercial immune-metric assays, such as enzyme-linked immunosorbent assays (ELISA), are frequently used for screening purposes as well. Recently, a variety of emerging methods have been proposed for the analysis of mycotoxins based on novel technologies, including immune-chromatography (i.e. lateral flow devices), fluorescence polarization immunoassays (FPIA), infrared spectroscopy (FT-NIR), molecularly imprinted polymers (MIPs) and optical biosensors. Examples for Commercially Available Rapid Analysis Test Systems: A) Test kits based on ELISA or LFD 1. Charm Sciences Inc. 2. EnviroLogix Inc. 3. Neogen Corporation 4. R-Biopharm AG 5. Romer Labs? 6. VICAM B) Test kits based on fluorescence polarization immunoassays 1. Aokin AG 2. Diachemix Inc. C) Test kits based on fluorometry ToxiMet Ltd Strength and weakness of enzyme-linked immunosorbent assay (ELISA), lateral flow detection (LFD) or fluorescence polarization immunoassay (FPI)named as Aflasafe? (www.aflasafe.com), which can be used on maize and groundnut. This product is an ecofriendly innovative biocontrol technology that utilizes native nontoxigenic strains of A. flavus to naturally out-compete their aflatoxin-producing cousins. Aflasafe? has been shown to consistently reduce aflatoxin contamination in maize and groundnut by 80e99% during crop development, postharvest storage, and throughout the value chain in several countries across Africa. Aflasafe products have been registered for commercial use in Kenya, Nigeria, Senegal and Gambia, while products are under development in seven other African nations]. Each Aflasafe? product contains four unique atoxigenic strains of A. flavus widely distributed naturally in the country where it is to be applied. Another study on biological control has found that inoculation of antagonistic strains of fluorescent Pseudomonas, Bacillus and Trichoderma spp. on peanuts resulted in significant reduction of pre-harvest seed infection by A. flavus. Other researchers demonstrated that the extract of Equisetum arvense and a mixture 1:1 of Equisetum arvense and Stevia rebaudiana is effective against growth of A. flavus and subsequent production of aflatoxin under pre-harvest conditions. A 71% reduction in AF contamination in soils and in groundnuts when an AF competitive exclusion strain of A. flavus AFCHG2 was applied to Argentinian groundnuts. Non-toxigenic strains of A. flavus were shown to mitigate AF contaminations in maize through pre-harvest field application. Furthermore, the efficacy of a bioplastic-based formulation for controlling AFs in maize were evaluated. The results showed that bio-control granules inoculated with A. flavus NRRL 30797 or NRRL 21882 reduced AF contaminations up to 90% in both non-Bt and Bt hybrids (Bt corn is a variant of maize that has been genetically altered to express one or more proteins from the bacterium Bacillus thuringiensis including Delta endotoxins. The protein is poisonous to certain insect pests. Spores of the bacillus are widely used in organic gardening, although GM corn is not considered organic). b) Sorting technology Sorting processes seek to eliminate agricultural products with substandard quality. Normally sorting, especially for grains, can be achieved based on differentiation of physical properties such as color, size, shape, and density as well as visible identification of fungal growth in affected crops. By rejecting damaged and discolored samples, sorting operations reduce the presence of AFs as well as contaminating materials in food and feed. Nonetheless, such physical methods are often laborious, inefficient, and impractical for in-line measurements. The application of computer-based image processing techniques is one of the most promising methods for large-scale screening of fungal and toxin contaminations in food and feed. Grains and other agricultural products contain various nutritional substances that are degraded by fungal growth, which in turn influence absorbance spectra of the material. It was also shown that it was possible to quantify fungal infection and metabolites such as mycotoxins produced in maize grain by Fusarium verticillioides using Near Infrared Spectroscopy (NIRS). NIRS successfully identified kernels contaminated with AFs. Moreover, some researchers highlighted NIRS technique as a fast and nondestructive tool for detecting mycotoxins such as AF-B1 in maize and barley at a level of 20 ppb. Nevertheless, NIRS only produces an average spectrum, which lacks in spatial information from the sample with respect to distribution of the chemical composition. Hyperspectral imaging (HSI) is another method that can be employed to monitor both the distribution and composition of mycotoxins in contaminated food samples, especially grains. This method can produce both localized information and a complete NIR spectrum in each pixel. Hyperspectral imaging (HSI) technique was also used to estimate AF contamination in maize kernels inoculated with A. flavus spores and demonstrated the potential for HSI based in the Vis/NIR range for quantitative identification and distinction of AFs in inoculated maize kernels. Nevertheless, all these spectral techniques require properly trained personal and equipment which is out of the reach of the small subsistence farmers that are typical of the underdeveloped countries in SubSahara Africa. c) Chemical control agents A number of studies have determined the effect of synthetic and natural food additives on AF reduction in food products. A prime example of this effect is citric acid on AF-B1 and AF-B2 degradation in extruded sorghum. The effect of sodium hydrosulfite (Na2S2O4 ) and pressure on the reduction of AFs in black pepper was investigated. The study reported that the application of 2% Na2S2O4 under high pressure resulted in a greater percentage reduction of AF-B1, AF-B2, AFG1, and AF-G2, without damage to the outer layer of black pepper. Nevertheless, AF-B2 was found to be the most resistant against the applied treatment. Apart from that, it is evident that respiration from insects increases the temperature and moisture content of grains providing favorable conditions for fungal growth. For this reason, the efficacy of 2, 6-di (t-butyl)-p-cresol) and the entomopathogenic fungus Purpureocillium lilacinum on the accumulation of AF-B1 in stored maize was evaluated. The results clearly showed that the highest reduction of AF-B1 in stored maize occurred with the combination of BHT and urpureocillium lilacinum. In addition, the effects of organic acids during soaking process on the reduction of AFs in soybean media were studied. The highest reduction rate of AF-B1 was obtained from tartaric acid followed by citric acid, lactic acid, and succinic acid, respectively. These acid treatments convert AF-B1 to β-keto acid that subsequently transforms to AF-D1, which has less toxicity than that of AFB1. Another novel technology was also reported that has been applied to inhibit AF contamination called acidic electrolyzed oxidizing water, which is an electrolyte solution prepared using an electrolysis apparatus with an ion-exchange membrane, used to decontaminate AF-B1 from naturally contaminated groundnut samples. This decreased the content of AF-B1 in groundnuts about 85% after soaking in the solution. Remarkably, the nutritional content and color of the groundnuts did not significantly change after treatment. To overcome the development of fungal resistance as well as residual toxicity posed by synthetic additives, the actions of some plant-based preservatives toward AF reduction have been studied in various food products. The effect of isothiocyanates, generated by enzymatic hydrolysis of glucosinolates, contained in oriental mustard flour were evaluated. The findings showed that isothiocyanates reduced A. parasiticus growth in groundnut samples, whereas the AF-B1, AFB2, AF-G1, and AF-G2 reduction ranged between 65 and 100%. Similar results were obtained by other researchers, who reported the inhibition of AFs by isothiocyanates derived from oriental and yellow mustard flours in piadina (a typical Italian flatbread) contaminated with A. parasiticus. These results can be explained by the electrophilic property of isothiocyanates, which can bind to thiol and amino groups of amino acids, peptides, and proteins, forming conjugates, dithiocarbamate, and thiourea structures leading to enzyme inhibition and subsequently to cell death. Due to fungicidal and anti-aflatoxigenic properties of neem leaves, the application of 20% neem powder fully inhibited all types of aflatoxins synthesis for 4 months in wheat and for 2 months in maize, whereas the inhibition of AF-B2, AF-G1, and AF-G2 was observed for 3 months in rice. d) Biological control agents at post-harvest processing stages Physical and chemical detoxification methods have some disadvantages, such as loss of nutritional value, altered organoleptic properties, and undesirable effects in the product as well as high cost of equipment and practical difficulties making them infeasible, particularly for lower-income countries. However, biological methods based on competitive exclusion by non-toxigenic fungal strains have been reported as a promising approach for mitigating formation of mycotoxins and preventing their absorption into the human body. Among various microorganisms, lactic acid bacteria (LAB) namely Lactobacillus, Bifidobacterium, Propionibacterium, and Lactococcus are reported to be active in terms of binding AF-B1 and AF-M1. The binding is most likely a surface phenomenon with a significant involvement of lactic acid and other metabolites such as phenolic compounds, hydroxyl fatty acids, hydrogen peroxide, reuterin (3- hydroxypropionaldehyde), and proteinaceous compounds produced by LAB. AF binding seems to be strongly related to several factors such as LAB strain, matrix, temperature, pH, and incubation time. Researchers found that Lactobacillus rhamnosus was the best strain with the ability to bind to AF-B1 in contaminated wheat flour during bread-making process. Other microorganisms have also been reported to bind or degrade aflatoxins in foods and feeds. The AF-B1 binding abilities of Saccharomyces cerevisiae strains in vitro in indigenous fermented foods from Ghana were tested. The results indicated that some strains of Saccharomyces cerevisiae have high AF-B1 binding capacity. These binding properties could be useful for the selection of starter cultures to prevent high AF contamination levels in relevant fermented foods. e) Packaging materials In post-harvest management, packaging materials are frequently considered as the final step of product development in order to extend the preservation of food and feed products. During storage and distribution, food commodities can be affected by a range of environmental conditions, such as temperature and humidity as well as light and oxygen exposure. Overall, these factors have been reported to facilitate various physicochemical changes such as nutritional degradation and browning reactions with the latter causing undesirable color changes. The interaction of these factors can also elevate the risks of fungal development and subsequent AF contamination. Many smallholder farmers in lower-income countries traditionally store agricultural products such as grains in containers typically made from wood, bamboo, thatch, or mud placed and covered with thatch or metal roofing sheets. Recently, metal or cement bins have been introduced as alternatives to traditional storage methods, but their high costs and difficulties with accessibility make adoption by small-scale farms limited. Polypropylene (PP) bags which are currently used for grains storage, are still contaminated by fungal AFs especially when those reused bags contain A. flavus spores. Several studies have reported the application of Purdue Improved Crop Storage (PICS) bags to mitigate fungal growth and resulting AF contamination. .PICS bags successfully suppressed the development of A. flavus and resulting AF contamination in maize across the wide range of moisture contents in comparison to non-hermetic containers. This could be a result of PICS bag construction consisting of triple bagging hermetic technology with two inner liners made of high density polyethylene (HDPE) and an outer layer woven PP. In addition, PICS bags reduced the oxygen influx and limited the escape of carbon dioxide, which can prevent the development of insects in stored grain. f) Benefits of good harvest management Many innovative management strategies that can potentially reduce AF contamination in food and feed chains have been identified by this review. These strategies have the potential to mitigate adverse effects of AF contamination on food security, public health, and economic development. An understanding of these benefits can motivate policy makers and value chain actors to explore effective ways of managing AFs during pre- and post-production processes. The quantity and quality of agricultural products are degraded by the presence of AFs, while the opposite is true when AF contamination is effectively prevented. The use of biocontrol methods for instance has been shown to reduce contamination up to 90%, which potentially reduces complete loss of harvested or stored crops. As mentioned earlier the use of the PICS technology for grain storage can reduce AF contamination due to the controlled environment in the hermitic bags. For subsistent households, such measures can potentially increase availability of harvested food crop for family consumption. Farmers can even afford to sell their excess produce and use the proceeds to purchase other food ingredients they do not produce themselves. Moreover, applications of innovative control technologies can ensure that products are safer to consume, thereby improving utilization efficiency. By reducing significant losses during storage, the control of AF can certify that the foodstuffs are available over extended periods of time, thereby ensuring consistent food availability. Effective control of AF contamination therefore has the potential to enhance food availability, food access, food utilization, and food stability. AFs are a serious risk to public health, especially in low-income countries where most people consume relatively large quantities of susceptible crops such as maize or sorghum. According to the estimation of the US Center for Disease Control and Prevention, about 4.5 billion people are chronically exposed to mycotoxins. Prolonged exposure to even low levels of AF contamination in crops could lead to liver damage or cancer as well as to immune disorders. In children, stunted growth and Kwashiorkor pathogenesis are caused by breast milk consumption or direct ingestion of AF-contaminated foods. Controlling AF contamination through the application of effective technologies could potentially avoid such health risks and have significant benefits in a number of ways. First chronic diseases can be prevented to minimize pressure on the health facilities of an economy due to savings on cost of medication and treatment. People will have access to good quality food ingredients for healthy living and making an efficient labor force available for the economy. g) Economic benefits The economic benefits of AF reduction are observed through both domestic and high-value international trade markets. At domestic and regional levels, markets might not reward reduced AF in crops, but avoiding contamination could allow, in ideal cases, to increase the volume of sales, which would lead to higher incomes as well as greater returns on investments for producers. Farmers who successfully inhibit AF contamination can also benefit from increased income due to greater product acceptance, higher market value, or access to high-value markets. In reality, there are numerous factors that have to be enhanced in order to create premium class products such as aflatoxin control, consumer awareness, marketing channels, aflatoxin testing, and stricter enforcement of production and market regulations. When such enabling conditions are met, it has been shown that aflatoxin conscious market can pay a premium for aflatoxin safe products even in the domestic market in Africa.