Natural occurrence of mycotoxins in staple cereals from Ethiopia

Analytical Determination of Aflatoxin in Ground Corn Check Samples Completed by Multiple Laboratories over Several Years

Mycotoxins are toxic molecules produced by multiple fungal species, including Aspergillus and Fusarium. Fungal infection of crops can result in mycotoxins entering the animal and human food supply. Enzyme-linked immunosorbent assays and other immunological assays have been developed to detect mycotoxins in foods. To calibrate the response of those methods, reference materials with known amounts of homogeneously dispersed mycotoxins are often utilized, where the mycotoxin concentrations have been determined using high-performance liquid chromatography coupled with absorbance or fluorescence detection methods, or high-performance liquid chromatography coupled with mass spectrometry detection methods. Therefore, it is important that the analytical methods provide accurate and precise quantitation of mycotoxins. The reference materials must also contain homogeneously dispersed known quantities of mycotoxin. To evaluate the accuracy and precision of mycotoxin reference materials and the analytical methods, quantitative results from multiple laboratories were completed each year for several years on ground corn check samples containing known levels of mycotoxins. Results for the quantitation of aflatoxin-containing corn reference samples are presented in this article.

Fusarium Species and Mycotoxins Associated with Sorghum Grains in Uruguay

Grain mold and stalk rot are among the fungal diseases that cause significant losses in sorghum worldwide and are caused by different Fusarium spp. The presence of Fusarium species in sorghum grains causes yield losses and mycotoxin contamination, which represents a risk to consumers. In this study, Fusarium graminearum species complex (FGSC) had a high incidence, followed by Fusarium fujikuroi species complex (FFSC) and F. incarnatum-equiseti species complex. Within FFSC, F. proliferatum, F. andiyazi, F. fujikuroi, F. thapsinum, F. verticillioides and F. subglutinans were identified, and this was the first report of F. fujikuroi in sorghum. The most frequent toxins found in sorghum samples were deoxynivalenol (DON) and zearalenone (ZEN). The presence of fumonisins and nivalenol (NIV) was detected at low levels. This study adds new knowledge about the occurrence of Fusarium species and mycotoxins in sorghum grains. Furthermore, this is the first report in Uruguay on fungicide sensitivity for Fusarium isolates from sorghum, which constitutes an important starting point for defining management practices to minimize fungal infection and mycotoxin contamination.

Type B Trichothecenes in Cereal Grains and Their Products: Recent Advances on Occurrence, Toxicology, Analysis and Post-Harvest Decontamination Strategies

Type B trichothecenes (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol) and deoxynivalenol-3-glucoside (DON-3G) are secondary toxic metabolites produced mainly by mycotoxigenic Fusarium fungi and have been recognized as natural contaminants in cereals and cereal-based foods. The latest studies have proven the various negative effects of type B trichothecenes on human health. Due to the widespread occurrence of Fusarium species, contamination by these mycotoxins has become an important aspect for public health and agro-food systems worldwide. Hence, their monitoring and surveillance in various foods have received a significant deal of attention in recent years. In this review, an up-to-date overview of the occurrence profile of major type B trichothecenes and DON-3G in cereal grains and their toxicological implications are outlined. Furthermore, current trends in analytical methodologies for their determination are overviewed. This review also covers the factors affecting the production of these mycotoxins, as well as the management strategies currently employed to mitigate their contamination in foods. Information presented in this review provides good insight into the progress that has been achieved in the last years for monitoring type B trichothecenes and DON-3G, and also would help the researchers in their further investigations on metabolic pathway analysis and toxicological studies of these Fusarium mycotoxins.

Occurrence of Aflatoxins in Poultry Feed in Selected Chicken Rearing Villages of Bishoftu Ethiopia

Background

Aflatoxins (AFs) are major contaminants of feed used in the poultry industry that negatively affect animal and human health. In Ethiopia, previous studies on AFs mainly considered cattle feed and milk but scarce information exists for poultry feeds.

Methods

The aim of this study was to determine the occurrence of AFs in poultry feed in selected chicken rearing villages of Bishoftu. The study was conducted from December 2018 to May 2019. Thirty-three compound poultry feed samples were collected and analyzed for aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and total AFs (AFT) using high performance liquid chromatography (HPLC). The moisture content of the samples was also determined.

Results

The result indicated that 31 (94%) from a total of 33 samples were contaminated with AFs. The mean levels of AFB1, AFB2, AFG1, AFG2 and AFT were 70.11 µg/kg, 13.50 µg/kg, 88.55 µg/kg, 18.00 µg/kg and 190.18 µg/kg, respectively. This study found AFs at a level above the limit of FDA regulatory levels of 20 µg/kg in 25 (72.75%) samples for AFT and 22 (66.67%) samples for AFB1. The analysis of moisture content of the samples, ranges from 7.33% to 11.17%, indicating all were at optimal value (<12%).

Conclusion

The study showed the high contamination of AFs in poultry feeds with optimal moisture content and hence further investigations are needed to address the cause. The study also supports the need for preventive strategies of AFs contamination in poultry feeds in Bishoftu.

Fungal Species and Multi-Mycotoxin Associated with Post-Harvest Sorghum (Sorghum bicolor (L.) Moench) Grain in Eastern Ethiopia

Sorghum is the main staple food crop in developing countries, including Ethiopia. However, sorghum grain quantity and quality are affected by contaminating fungi both under field and post-harvest stage. The aim of the current study was to assessed fungal species and multi-mycotoxins associated with sorghum grain in post-harvest samples collected from eastern Ethiopia. Fungal genera of Aspergillus, Alternaria, Bipolaris, Fusarium, Mucor, Penicillium, and Rhizoctonia were recovered in the infected grain. A liquid chromatography-tandem mass spectrometric (LC-MS/MS) was used for quantification of multiple mycotoxins/fungal metabolites. Overall, 94 metabolites were detected and grouped into eight categories. All metabolites were detected either in one or more samples. Among major mycotoxins and derivatives, deoxynivalenol (137 μg/kg), zearalenone (121 μg/kg), ochratoxin A (115 μg/kg), and fumonisin B₁ (112 μg/kg) were detected with maximum concentrations, while aflatoxin B₁ had relatively lower concentrations (23.6 μg/kg). Different emerging mycotoxins were also detected, with tenuazonic acid (1515 μg/kg) occurring at the maximum concentration among Alternaria metabolites. Fusaric acid (2786 μg/kg) from Fusarium metabolites and kojic acid (4584 μg/kg) were detected with the maximum concentration among Fusarium and Aspergillus metabolites, respectively. Unspecific metabolites were recognized with neoechinulin A (1996 μg/kg) at the maximum concentration, followed by cyclo (L-Pro-L-Tyr) (574 μg/kg) and cyclo (L-Pro-L-Val) (410 μg/kg). Moreover, metabolites form other fungal genera and bacterial metabolites were also detected at varying levels. Apparently, the study revealed that sorghum grains collected across those districts were significantly contaminated with co-occurrences of several mycotoxins. Farmers should be the main target groups to be trained on the improved management of sorghum production.

Fumonisins in African Countries

Maize and other cereals are the commodities most contaminated with fumonisins. The maize acreage is increasing in Africa, and the maize harvest provides important foods for humans and feeds for domestic animals throughout the continent. In North Africa, high levels of fumonisins have been reported from Algeria and Morocco, while low levels have been detected in the rather few fumonisin analyses reported from Tunisia and Egypt. The West African countries Burkina Faso, Cameroon, Ghana, and Nigeria all report high levels of fumonisin contamination of maize, while the few maize samples analysed in Togo contain low levels. In Eastern Africa, high levels of fumonisin contamination have been reported from the Democratic Republic of Congo, Ethiopia, Kenya, Tanzania, and Uganda. The samples analysed from Rwanda contained low levels of fumonisins. Analysis of maize from the Southern African countries Malawi, Namibia, South Africa, Zambia, and Zimbabwe revealed high fumonisin levels, while low levels of fumonisins were detected in the few analyses of maize from Botswana and Mozambique.

The cost of postharvest losses in Ethiopia: economic and food security implications

This research was designed to estimate the food security and economic burdens of postharvest losses of important food and cash crops produced in Ethiopia. Data of food production, food values and consumption patterns as well as the number of severely and moderately food insecure persons were obtained from FAOSTAT database for Ethiopia. The food security implications of the postharvest losses in the country showed that a volume of crops that could feed over 23 million citizens could be saved with proper postharvest management. The economic meaning of the losses of major food and cash crops was 1.2 billion US dollars per annum, which literally is 10% of the average annual national budget of the country for the years 2018–2022. If the losses could be managed to be lower by 50%, it could have meaningfully contributed to the food and nutrition security as well as the GDP of the country. The approach used in the current analysis could be either adopted to generate clear data for awareness creation community education or it could be developed into a more robust model to estimate annual losses or food security and economic gain potentials.

Magnitude of Aflatoxigenic Aspergillus Species, Level of Aflatoxin B1, and Associated Factors in Stored Feed at Poultry Farms in Dire Dawa, Ethiopia

Aflatoxin, the secondary toxic metabolite of Aspergillus species, particularly aflatoxigenic Aspergillus flavus and parasiticus, has a detrimental effect on poultry health and production. There exists some information gap about the magnitudes of aflatoxigenic Aspergillus species and aflatoxin in poultry feeds in the study area. Thus, the study was conducted to estimate the magnitude and assess the related potential factors of aflatoxigenic Aspergillus species with evaluations of the level of aflatoxin B1 in stored poultry feed at selected farms in Dire Dawa, Ethiopia. A cross-sectional study design was carried out on 374 poultry feed samples recruited by using a stratified simple random sampling technique. A pretested structured questionnaire was used to assess the level of knowledge and prevention practices associated with aflatoxin in poultry feed. The isolation of aflatoxigenic Aspergillus species was made by Aspergillus flavus parasiticus media, and aflatoxin B1 was estimated by aflatoxin B1 enzyme-linked immune sorbent assay. Results showed that the magnitude of aflatoxigenic Aspergillus species was 72.5% (95% CI: 67.6-76.9). The odds at which the species isolated were higher (p < 0.05) in feeds stored more than two months (AOR = 2.69), the presence of rodents in the storing room (AOR = 2.67), feeds having high moisture content (AOR = 1.5), and feed ingredient types (AOR = 4.3) compared to their counter parts. Only 34.4 and 32.8 percent of the respondents have better knowledge and apply prevention practice about fungal contamination and aflatoxin production in poultry feed, respectively. The occurrence of aflatoxigenic Aspergillus species in poultry feed was associated with the presence of rodents in the feed storing room with long storing period and high moisture contents of the feed. The knowledge and prevention practices employed by farm managers and workers about fungal contamination and aflatoxin in poultry feed are found low.

Case-Control Study of Nodding Syndrome in Acholiland: Urinary Multi-Mycotoxin Screening

This case-control study adds to the growing body of knowledge on the medical, nutritional, and environmental factors associated with Nodding Syndrome (NS), a seizure disorder of children and adolescents in northern Uganda. Past research described a significant association between NS and prior history of measles infection, dependence on emergency food and, at head nodding onset, subsistence on moldy maize, which has the potential to harbor mycotoxins. We used LC-MS/MS to screen for current mycotoxin loads by evaluating nine analytes in urine samples from age-and-gender matched NS cases (n = 50) and Community Controls (CC, n = 50). The presence of the three mycotoxins identified in the screening was not significantly different between the two groups, so samples were combined to generate an overall view of exposure in this community during the study. Compared against subsequently run standards, α-zearalenol (43 ± 103 µg/L in 15 samples > limit of quantitation (LOQ); 0 (0/359) µg/L), T-2 toxin (39 ± 81 µg/L in 72 samples > LOQ; 0 (0/425) µg/L) and aflatoxin M1 (4 ± 10 µg/L in 15 samples > LOQ; 0 (0/45) µg/L) were detected and calculated as the average concentration ± SD; median (min/max). Ninety-five percent of the samples had at least one urinary mycotoxin; 87% were positive for two of the three compounds detected. While mycotoxin loads at NS onset years ago are and will remain unknown, this study showed that children with and without NS currently harbor foodborne mycotoxins, including those associated with maize.

Overview of Portable Assays for the Detection of Mycotoxins, Allergens, and Sanitation Monitoring

BACKGROUND

Many food recalls are related to the presence of undeclared allergens and microorganisms in food products. To reduce these occurrences, portable diagnostic assay kits are available to quantitate mycotoxins, to detect allergens and gluten in foods and on environmental surfaces, and for sanitation monitoring.

OBJECTIVE

This article reviews diagnostic kits that can detect sources of contamination in food and ingredients as well as on surfaces and clean-in-place rinses.

METHOD

Mycotoxins and gluten were detected using lateral flow diagnostic assays. Sanitation monitoring of surfaces was completed using a chemiluminescent assay to detect adenosine 5'-triphosphate disodium salt hydrate (ATP) and another assay to detect protein.

RESULTS

Gluten was detected at 10 ppm in spiked commodities and on wet and dry surfaces at 2.5 µg/100cm2. Deoxynivalenol was quantitated in dry distillers grains plus solubles and mean results were within two SDs of those determined by HPLC. The chemiluminescent assay had an LOD of 6 fmol of ATP and was able to detect a 1:10 000 dilution of orange juice from surfaces. The protein assay detected 5 µg of bovine serum albumin (BSA) directly applied to the sampler, 100 µg of BSA on surfaces, and detected 1:10 dilutions of Greek yogurt and raw beef from surfaces.

CONCLUSIONS

Portable diagnostic kits evaluated in this work provided accurate, rapid, and sensitive results for detection of mycotoxins, gluten, proteins, and ATP. These methods can be used in facilities with minimal training and provide results that are important to ensure food safety.

HIGHLIGHTS

Portable methods to detect gluten, mycotoxins, proteins, and ATP are presented.

Fungal diversity of "solom" a Ghanaian traditional beverage of millet (Pennisetum glaucum)

The association of cereals with fungi cannot be disregarded as their manifestation in our foods poses serious health risks. The aim of this study was to investigate the mycofloral (fungal) and chemical (pH) qualities of the "solom" (beverage of millet) available for consumption from their respective sales points in Ho. "Solom" a cereal beverage of millet was sampled from ten (10) different locations in the Ho Municipality of Ghana and evaluated for their pH, fungal counts, and species diversity. Mycological analyses were done on Oxytetracycline Glucose Yeast Extract (OGYE) and Dichloran Rose Bengal Chloramphenicol (DRBC) media from three (3) points per location using serial dilution. A total of fourteen (14) fungal species belonging to eight (8) genera were isolated on both media; Aspergillus (A. niger, A. flavus, A. fumigatus, A. parasiticus, A. alutaceaus, A. terreus), Rhizopus (R. stolonifer), Mucor (M. racemosus), Fusarium (F. oxysporum), Penicillium (P. digitatum, P. verucosum), Cladosporium (C. cladosporoides), Curvularia (C. lunata), and Rhodotorula sp. were recorded. Fungal counts on both media ranged between 1.68 ± 0.8 and 4.11 ± 0.9 log10 CFU/ml. There were statistically significant (p < .05) differences observed in the samples from different locations. The values of pH recorded were in the range of 3.03 ± 0.09-4.03 ± 0.23 and showed no significant differences (p > .05) among them. All samples were found to be in the acceptable range of values prescribed by the International Commission for Microbiological Specification of Foods (ICMSF, 1998). Good Manufacturing Practices (GMP) and Good Hygiene Practices (GHP) should be employed to enhance food safety.

Occurrence, Impact on Agriculture, Human Health, and Management Strategies of Zearalenone in Food and Feed: A Review

Mycotoxins represent an assorted range of secondary fungal metabolites that extensively occur in numerous food and feed ingredients at any stage during pre- and post-harvest conditions. Zearalenone (ZEN), a mycotoxin categorized as a xenoestrogen poses structural similarity with natural estrogens that enables its binding to the estrogen receptors leading to hormonal misbalance and numerous reproductive diseases. ZEN is mainly found in crops belonging to temperate regions, primarily in maize and other cereal crops that form an important part of various food and feed. Because of the significant adverse effects of ZEN on both human and animal, there is an alarming need for effective detection, mitigation, and management strategies to assure food and feed safety and security. The present review tends to provide an updated overview of the different sources, occurrence and biosynthetic mechanisms of ZEN in various food and feed. It also provides insight to its harmful effects on human health and agriculture along with its effective detection, management, and control strategies.

Aflatoxin exposure among lactating women in southern Ethiopia

In Ethiopia and many other low-income countries, little is known about the exposure of lactating women to aflatoxin, which is a major health concern to the mother and her nursing infant. We determined the aflatoxin B1 contamination of family foods (AFB1) and urinary aflatoxin M1 (AFM1) of lactating women in Sidama, southern Ethiopia, and compared the levels across agroecological settings (lowland, midland, highland) and two seasons. We conducted two surveys (n = 360) that represented the dry and wet seasons of the locality. AFM1 and AFB1 were determined using enzyme-linked immunosorbent assay (ELISA). Statistical analysis was made using Mann-Whitney U test and Kruskal-Wallis test. The median (interquartile range) AFB1 was 0.94 (0.63-1.58) ppb. AFB1 was detected in 95.6% of the food samples, and 13.6% exceeded the 2.0 ppb threshold. We observed an increasing trend for aflatoxin exposure from highland to lowland (p < .001), but there was no difference between seasons (p = .743). The median (interquartile range) urinary AFM1 was 214 (undetectable to 2,582) ppt, and AFM1 was detectable in 53.3% of the samples. Urinary AFM1 showed significant difference among agroecological zones (p < .001) but not between seasons (p = .275). A significant but weak correlation was observed between AFB1 and urinary AFM1 (rs  = 0.177, p = .001). We concluded that lactating women in Sidama, especially those in the lowland area, have unsafe exposure to aflatoxin.

Mycotoxins in Ethiopia: A Review on Prevalence, Economic and Health Impacts

Mycotoxigenic fungi and their toxins are a global concern, causing huge economic and health impacts in developing countries such as Ethiopia, where the mycotoxin control system is inadequate. This work aimed to review the occurrences of agriculturally essential fungi such as Aspergillus, Fusarium, and Penicillium and their major mycotoxins in Ethiopian food/feedstuffs. The incidents of crucial toxins, including aflatoxins (B1, B2, G1, G2, M1), fumonisins (B1, B2), zearalenone, deoxynivalenol, and ochratoxin A, were studied. The impacts of chronic aflatoxin exposure on liver cancer risks, synergy with chronic hepatitis B infection, and possible links with Ethiopian childhood malnutrition were thoroughly examined. In addition, health risks of other potential mycotoxin exposure are also discussed, and the impacts of unsafe level of mycotoxin contaminations on economically essential export products and livestock productions were assessed. Feasible mycotoxin mitigation strategies such as biocontrol methods and binding agents (bentonite) were recommended because they are relatively cheap for low-income farmers and widely available in Ethiopia, respectively. Moreover, Ethiopian mycotoxin regulations, storage practice, adulteration practice, mycotoxin tests, and knowledge gaps among value chain actors were highlighted. Finally, sustained public awareness was suggested, along with technical and human capacity developments in the food control sector.

Variation of Fusarium Free, Masked, and Emerging Mycotoxin Metabolites in Maize from Agriculture Regions of South Africa

The presence of mycotoxins in cereal grain is a very important food safety issue with the occurrence of masked mycotoxins extensively investigated in recent years. This study investigated the variation of different Fusarium metabolites (including the related regulated, masked, and emerging mycotoxin) in maize from various agriculture regions of South Africa. The relationship between the maize producing regions, the maize type, as well as the mycotoxins was established. A total of 123 maize samples was analyzed by a LC-MS/MS multi-mycotoxin method. The results revealed that all maize types exhibited a mixture of free, masked, and emerging mycotoxins contamination across the regions with an average of 5 and up to 24 out of 42 investigated Fusarium mycotoxins, including 1 to 3 masked forms at the same time. Data obtained show that fumonisin B1, B2, B3, B4, and A1 were the most prevalent mycotoxins and had maximum contamination levels of 8908, 3383, 990, 1014, and 51.5 µg/kg, respectively. Deoxynivalenol occurred in 50% of the samples with a mean concentration of 152 µg/kg (max 1380 µg/kg). Thirty-three percent of the samples were contaminated with zearalenone at a mean concentration of 13.6 µg/kg (max 146 µg/kg). Of the masked mycotoxins, DON-3-glucoside occurred at a high incidence level of 53%. Among emerging toxins, moniliformin, fusarinolic acid, and beauvericin showed high occurrences at 98%, 98%, and 83%, and had maximum contamination levels of 1130, 3422, and 142 µg/kg, respectively. Significant differences in the contamination pattern were observed between the agricultural regions and maize types.

Phylogenetically Diverse Fusarium Species Associated with Sorghum (Sorghum Bicolor L. Moench) and Finger Millet (Eleusine Coracana L. Garten) Grains from Ethiopia

Fusarium is one of the most diverse fungal genera affecting several crops around the world. This study describes the phylogeny of Fusarium species associated with grains of sorghum and finger millet from different parts of Ethiopia. Forty-two sorghum and 34 finger millet grain samples were mycologically analysed. All of the sorghum and more than 40% of the finger millet grain samples were contaminated by the Fusarium species. The Fusarium load was higher in sorghum grains than that in finger millet grains. In addition, 67 test isolates were phylogenetically analysed using EF-1α and β-tubulin gene primers. Results revealed the presence of eight phylogenetic placements within the genus Fusarium, where 22 of the isolates showed a close phylogenetic relation to the F. incarnatum–equiseti species complex. Nevertheless, they possess a distinct shape of apical cells of macroconidia, justifying the presence of new species within the Fusarium genus. The new species was the most dominant, represented by 33% of the test isolates. The current work can be seen as an important addition to the knowledge of the biodiversity of fungal species that exists within the Fusarium genus. It also reports a previously unknown Fusarium species that needs to be investigated further for toxin production potential.

Natural occurrence of mycotoxins in maize and sorghum in Togo

Mycotoxins are fungal secondary metabolites frequently affecting agronomical crops and consequently imposing a major challenge for food safety and public health. In this study, a total of 67 raw cereals (55 maize and 12 sorghum) were collected from the market of Togo. The samples were investigated on the occurrence of 21 mycotoxins using state-of-the-art high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The most frequent occurring mycotoxins were fumonisins (88 and 67% for maize and sorghum respectively) with concentrations ranging from 101 to 1838 μg/kg for maize and 81.5 to 361 μg/kg for sorghum, respectively. Aflatoxin B1 was detected in 38% of the maize samples with maximum contamination levels of 256 μg/kg, and 25% of the sorghum samples (range 6-16 μg/kg). The concentrations of aflatoxins were high in maize, with some cases exceeding the maximum legislative limits (EU) for unprocessed maize placed on the market. In addition to these high contamination levels, the co-occurrence of three classes of mycotoxins (i.e., aflatoxins, fumonisins, and trichothecenes) was observed in this study. For the first time, the multi-mycotoxins occurrence in agronomical crops in Togo was reported.

Occurrence and Human-Health Impacts of Mycotoxins in Somalia

Mycotoxins are secondary metabolites produced by various molds that contaminate many staple foods and cause a broad range of detrimental health effects in animals and humans through chronic exposure or acute toxicity. As such, the worldwide contamination of food and feed with mycotoxins is a significant problem, especially in sub-Saharan Africa. In this study, mycotoxin occurrence in staple foods consumed in Somalia was determined. 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 a UPLC-MS/MS multimycotoxin 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 limits and guidance values. The average probable daily intake of fumonisins (FB₁ and FB₂) was 16.70 μg per kilogram of body weight (kg bw) per day, representing 835% of the recommended provisional maximum tolerable daily intake value of 2 μg/(kg bw)/day. A risk characterization revealed a mean national margin of exposure of 0.62 for AFB₁ with an associated risk of developing primary liver cancer estimated at 75 cancers per year per 100 000 people for white-maize consumption alone. The results clearly indicate that aflatoxin and fumonisin exposure is a major public-health concern and that risk-management actions require prioritization in Somalia.

Occurrence of aflatoxin in agricultural produce from local markets in Burundi and Eastern Democratic Republic of Congo

Aflatoxins are noxious secondary metabolites, of certain fungal species, found in food and feed. Contamination of a commodity with aflatoxins is associated with production and storage losses, and subsequently less food availability. Aflatoxins can also pose human health risks and represent a barrier to the development of trade, in both domestic and international markets. In this study, samples of cassava, maize, groundnut, beans, soybean, sorghum and milk, and their processed products were collected from local markets in Burundi and Eastern DRC. In order to investigate the levels of aflatoxin, crop samples were analyzed using a single step lateral flow immunochromatographic assay (Reveal Q+), while enzyme‐linked immune‐sorbent assay (ELISA) was used to analyze aflatoxin‐M₁ in milk, yogurt, and cheese samples. The results revealed the presence of aflatoxins in all samples from both countries, with levels ranging from 1.3 to 2,410 μg/kg. Samples collected from Burundi contained relatively higher (p > 0.0.5) levels of aflatoxins. In 51% of all the crops samples, total aflatoxin contamination was above the EU maximum tolerable level of 4 μg/kg. Processed products, particularly from groundnut, maize, and sorghum, had the highest levels of aflatoxin contamination when compared to unprocessed grain. With regard to milk and dairy products, the level of aflatoxin‐M₁ ranged from 4.8 to 261.1 ng/kg. Approximately 29% of milk and yogurt samples had aflatoxin‐M₁ higher than the EU regulatory limit of 50 ng/kg, whereas 20% of cheese samples were found to be contaminated at levels higher than the maximum limit of 250 ng/kg. These results can serve as the basis for pre‐ and postharvest approaches to reduce aflatoxin contamination in agricultural commodities in Burundi and Eastern DRC in order to reduce health risk, avoid reduced production in livestock, and open up export markets.

An HPLC-FLD method to measure ochratoxin A in teff (Eragrostis tef) and wheat (Triticum spp.) destined for the local Ethiopian market

Wheat (Triticum spp.) is among the top cereal grains in terms of production and consumption in Ethiopia. It can be typically infected with ochratoxin A (OTA) producing fungi both in the field and during storage resulting in animal and human health problems. While there is a wealth of information on the presence of OTA in wheat, the incidence of OTA in teff (Eragrostis tef), a cereal grain produced and consumed traditionally in Ethiopia and Eretria, remains insufficient. The purpose of this study was to develop and validate a high performance liquid chromatography (HPLC) method for OTA analysis in teff and wheat flours and to analyse the characteristic distribution of OTA in teff and wheat flours samples destined for local consumption in Ethiopia using a survey-approach. Wheat and teff flour samples were examined for OTA contamination. OTA was detected in 20% of the teff flour samples and in 50% of the wheat flour samples with median contamination levels of 1.04 μg/kg (limit of detection (LOD) = 0.78 μg/kg) and 7.23 μg/kg (LOD = 0.58 μg/kg) respectively. The validated method for OTA detection and quantification in teff and wheat using HPLC meets the European Union performance criteria for OTA (EC 2006/401) and the Eurachem Guideline validation requirements. An insight into the occurrence of OTA in teff is very valuable because the cereal might provide a lower OTA risk alternative for wheat in Ethiopia. In addition, for the world market, an insight into the occurrence of OTA in teff is important in the light of an increasing interest in teff as a gluten free cereal.

Effect of water activity, temperature, and incubation period on fungal growth and ochratoxin A production on Nyjer seeds

Aspergillus fresenii and Aspergillus sulphureus produce ochratoxin A (OTA), which is a secondary metabolite of Aspergillus and Penicillium species, with nephrotoxic effects and potential carcinogenic activity. The aim of this study was to determine the effects of temperature (20, 30, and 37 °C), water activity (0.82, 0.86, 0.90, 0.94, and 0.98 a_w), incubation period (5, 10, 15, and 30 days) on fungal growth, and OTA production by A. fresenii and A. sulphureus on Nyjer oil seeds. There was no fungal growth at 0.82 a_w. The two fungal species were able to produce OTA from the fifth day of incubation from 0.86 to 0.98 a_w and temperature 20 to 37 °C. Aspergillus fresenii produced the highest concentration of OTA (643 μg/kg) at 0.90 a_w and 37 °C within 15 days, while A. sulphureus produced the highest level of OTA (724 μg/kg) at 0.98 a_w and 20 °C within 10 days. The optimum water activity and temperature for the growth of both fungi were similar at 0.94 a_w and at 30 °C. There was statistically significant difference between the levels of OTA production among the two fungi. Overall, A. sulphureus produced significantly higher levels of OTA (p < 0.05). Higher temperature (37 °C) and 0.90-0.94 a_w were optimal for OTA production by A. fresenii. Our results show that Nyjer seeds can support the growth of A. fresenii and A. sulphureus and OTA production, and the two species had similar temperature and water activity requirements for growth but different requirements for OTA production on Nyjer seeds.

Aflatoxin B1, ochratoxin A and zearalenone in sorghum grains marketed in Tunisia

A total of 64 samples of sorghum (37 Tunisian sorghum samples and 27 Egyptian sorghum samples) were collected during 2011-2012 from markets in Tunisia. Samples were analysed for contamination with aflatoxin B1, ochratoxin A and zearalenone by High-Performance Liquid Chromatography Coupled with Fluorescence Detection (HPLC-FLD). Aflatoxin B1 was found in 38 samples in the range 0.03-31.7 µg kg^-1. Ochratoxin A was detected in 24 samples with concentrations ranging from 1.04 to 27.8 µg kg^-1. Zearalenone was detected in 21 samples and the concentration varied between 3.7 and 64.5 µg kg^-1. ANOVA analysis of the influence of the country of origin on the incidence and concentration of mycotoxins in the samples studied showed no significant difference (P > 0.05) between the two batches of samples for each of the three mycotoxins studied. The studied mycotoxins contaminate sorghum and may also co-exist because of the diversity of the mycobiota in this cereal.

Engaging One Health for Non-Communicable Diseases in Africa: Perspective for Mycotoxins

The role of mycotoxins-e.g., aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, tremorgenic toxins, and ergot alkaloids-has been recognized in the etiology of a number of diseases. In many African countries, the public health impact of chronic (indoor) and/or repeated (dietary) mycotoxin exposure is largely ignored hitherto, with impact on human health, food security, and export of African agricultural food products. Notwithstanding, African scientific research reached milestones that, when linked to findings gained by the international scientific community, make the design and implementation of science-driven governance schemes feasible. Starting from Nigeria as leading African Country, this article (i) overviews available data on mycotoxins exposure in Africa; (ii) discusses new food safety issues, such as the environment-feed-food chain and toxic exposures of food producing animals in risk assessment and management; (iii) identifies milestones for mycotoxins risk management already reached in West Africa; and (iv) points out preliminary operationalization aspects for shielding communities from direct (on health) and indirect (on trade, economies, and livelihoods) effects of mycotoxins. An African science-driven engaging of scientific knowledge by development actors is expected therefore. In particular, One health/One prevention is suggested, as it proved to be a strategic and sustainable development framework.

Chemical composition and food uses of teff (Eragrostis tef)

Teff (Eragrostis tef) is a cereal native to Ethiopia and Eritrea. It has an excellent adaptability to harsh environmental conditions and plays an important role in food security. In recent years, teff is becoming globally popular due to the attractive nutritional profile such as gluten free and high dietary fiber content. This review documents the recent advances in the genetic diversity, nutritional composition and food uses of teff grain. The attractive nutrients of teff include protein, dietary fiber, polyphenols, and certain minerals. Whole grain teff flour becomes increasingly important in healthy food market, and has been used to produce various gluten free food items such as pasta and bread. Efforts have been made to enhance the sensory quality of teff based products. There is great potential to adapt teff to the other parts of the world for healthy food and beverage production.

Natural occurrence of fumonisins B1 and B2 in maize from eight provinces of China in 2014

A total of 249 maize kernel samples from 8 maize-producing provinces of China were collected after the harvest season in 2014. All samples were analysed using high-performance liquid chromatography. The incidences of FBs (FB₁ + FB₂) from Guizhou, Hebei, Inner Mongolia, Shanxi, Chongqing, Liaoning, Heilongjiang, and Henan provinces were 71.4%, 73.8%, 28.0%, 52.6%, 85.0%, 87.5%, 38.1%, and 100.0%, respectively. The average concentration of FBs was 817 µg kg^-1 and the concentrations ranged from <6 to 15,252 µg kg^-1. Among the 249 maize kernel samples, 28 samples exhibited higher levels as set by the Food and Drug Administration (2000 µg kg^-1), whereas 12 samples exhibited higher levels as set by the European Commission (4000 µg kg^-1). The average exposure to FBs (0.12 µg kg^-1 body weight/day) is within the provisional maximum tolerable daily intake of 2.0 µg kg^-1 body weight as set by the Joint FAO/WHO Expert Committee on Food Additives.

The Status of Fusarium Mycotoxins in Sub-Saharan Africa: A Review of Emerging Trends and Post-Harvest Mitigation Strategies towards Food Control

Fusarium fungi are common plant pathogens causing several plant diseases. The presence of these molds in plants exposes crops to toxic secondary metabolites called Fusarium mycotoxins. The most studied Fusarium mycotoxins include fumonisins, zearalenone, and trichothecenes. Studies have highlighted the economic impact of mycotoxins produced by Fusarium. These arrays of toxins have been implicated as the causal agents of wide varieties of toxic health effects in humans and animals ranging from acute to chronic. Global surveillance of Fusarium mycotoxins has recorded significant progress in its control; however, little attention has been paid to Fusarium mycotoxins in sub-Saharan Africa, thus translating to limited occurrence data. In addition, legislative regulation is virtually non-existent. The emergence of modified Fusarium mycotoxins, which may contribute to additional toxic effects, worsens an already precarious situation. This review highlights the status of Fusarium mycotoxins in sub-Saharan Africa, the possible food processing mitigation strategies, as well as future perspectives.

Occurrence of Fusarium Mycotoxins in Cereal Crops and Processed Products (Ogi) from Nigeria

In Nigeria, maize, sorghum, and millet are very important cash crops. They are consumed on a daily basis in different processed forms in diverse cultural backgrounds. These crops are prone to fungi infestation, and subsequently may be contaminated with mycotoxins. A total of 363 samples comprising of maize (136), sorghum (110), millet (87), and ogi (30) were collected from randomly selected markets in four agro-ecological zones in Nigeria. Samples were assessed for Fusarium mycotoxins contamination using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Subsequently, some selected samples were analysed for the occurrence of hidden fumonisins. Overall, 64% of the samples were contaminated with at least one toxin, at the rate of 77%, 44%, 59%, and 97% for maize, sorghum, millet, and ogi, respectively. Fumonisins were the most dominant, especially in maize and ogi, occurring at the rate of 65% and 93% with mean values of 935 and 1128 μg/kg, respectively. The prevalence of diacetoxyscirpenol was observed in maize (13%), sorghum (18%), and millet (29%), irrespective of the agro-ecological zone. Other mycotoxins detected were deoxynivalenol, zearalenone, and their metabolites, nivalenol, fusarenon-X, HT-2 toxin, and hidden fumonisins. About 43% of the samples were contaminated with more than one toxin. This study suggests that consumption of cereals and cereal-based products, ogi particularly by infants may be a source of exposure to Fusarium mycotoxins.

Assessment of mothers’ knowledge and practice towards aflatoxin contamination in complementary foods in Ethiopia: from pre-harvest to household

This study assessed the knowledge and practices of the mothers in Ethiopia on issues related to aflatoxin in complementary foods (CFs) using structured questionnaires. The study involved 195 mothers from Amhara, Tigray, Oromia, and Southern Nations Nationalities and Peoples (SNNP) regions and addressed a range of issues used to prevent the risks of mould and aflatoxin contamination from farm-to-table. Of the 195 mothers who responded; 186 (95%) were ploughing their land before growing the next crop, 177 (91%) used the crop rotation schedule, 157 (81%) reported the practice of removing old seed heads and stalks used as an inoculum for aflatoxin contamination, 185 (95%) harvested the crops as soon as the crops were matured, 138 (70%) used a threshing method known as ‘trampling by hoofed animals’. After threshing, about 124 (64%) respondents had the knowledge and practice of drying cereals and legumes to decrease the moisture content, 134 (68%) used solar drying on a bare ground, 184 (94%) cleaned and disinfected the storage structures before storage. Almost all the respondents practiced the CFs processing steps properly and they used colour, type, odour, insect infestations, mouldiness and all these criteria to select the CFs ingredients. A total of 78 (40%) respondents had the practice of feeding mouldy cereals and legumes to animals, and 89 (46%) of the respondents erroneously believed that roasting can decontaminate the aflatoxin produced from mouldy cereals. As a general conclusion, the majority of the respondents are practicing good agricultural practices in the field, but they use poor storage and processing practices at homes which are susceptible to mould and aflatoxin contamination. Besides, they lack awareness about the toxic effects of aflatoxin on human health. Therefore, awareness creation about the health impacts of aflatoxin and methods of prevention need to be implemented in the study areas.

Evolution of fungal population and mycotoxins in sorghum silage

Silage, one of the most important feed sources for cattle, is vulnerable to contamination by spoilage moulds and mycotoxins because ensilage materials are excellent substrates for fungal growth. The aim of this study was to identify the mycobiota of sorghum silages, to determine the presence of aflatoxins and fumonisins, and to correlate these results with physical parameters of the silage. A total of 275 samples of sorghum were collected from dairy farms in the south-west region of Uruguay were silage practices are developed. The presence of fungi was observed in all of the sorghum samples with values varying from 0.2 × 10⁴ to 4085 × 10⁴ UFC g^-1. Significant difference were detected in the total number of fungi during the storage period; at six months there is a high risk of fungal spoilage. The most frequent genera isolated from sorghum samples were Penicillium (70%), Aspergillus (65%), Absidia (40%), Fusarium (35%), Paecilomyces (35%) and Alternaria, Cladosporium, Gliocadium and Mucor (30%). The toxigenic species most frequently found were Penicillium citrinum, Aspergillus flavus and Fusarium nygamai. Only two samples were contaminated by AFB1 with levels of 1 and 14 µg kg^-1. Fumonisin was detected in 40% of freshly harvest samples with levels ranged from 533 µg kg^-1 to 933 µg kg^-1. The use of silo bags seems to be an effective tool to store sorghum. However, the presence of toxigenic fungi show that regular screening for mycotoxins levels in silages must be performed to avoid the exposure of animals to contaminated feed and the introduction of these compounds into the food chain.

Aflatoxin B1 and total fumonisin contamination and their producing fungi in fresh and stored sorghum grain in East Hararghe, Ethiopia

Natural contamination of sorghum grains by aflatoxin B₁ and total fumonisin and their producing toxigenic fungi has been studied. A total of 90 sorghum grain samples were collected from small-scale farmers' threshing floors and 5-6 months later from underground pits during 2013 harvest from three districts of East Hararghe, Ethiopia. Mycotoxin analysis was done using enzyme-linked immunosorbent assay (ELISA). The limits of detection were in the range 0.01-0.03 μg kg^-1. The results revealed that all sorghum grain samples were contaminated with both Aspergillus and Fusarium species. Aflatoxin B₁ was detected at levels ranging from <LOD to 33.10 µg kg^-1 grain. There were marked variations in aflatoxin B₁ concentrations between fresh and stored samples, with much higher levels in the latter. Total fumonisin levels varied between 907 and 2041 µg kg^-1 grain across the samples. Lowest total fumonisin was recorded in freshly harvested sorghum grain samples. Sorghum is a main staple cereal in the studied districts and its consumption per day per person is high. Daily intake of low doses of mycotoxin-contaminated food stuff over a period of time could lead to chronic mycotoxicosis.

Assessment of the WHO Stunting Framework using Ethiopia as a case study

Poor linear growth in children <5 years old, or stunting, is a serious public health problem particularly in Sub-Saharan Africa. In 2013, the World Health Organization (WHO) released a conceptual framework on the Context, Causes and Consequences of Childhood Stunting (the 'WHO framework') that identifies specific and general factors associated with stunting. The framework is based upon a global review of data, and we have applied it to a country-level analysis where health and nutrition policies are made and public health and nutrition data are collected. We reviewed the literature related to sub-optimal linear growth, stunting and birth outcomes in Ethiopia as a case study. We found consistent associations between poor linear growth and indicators of birth size, recent illness (e.g. diarrhoea and fever), maternal height and education. Other factors listed as causes in the framework such as inflammation, exposure to mycotoxins and inadequate feeding during and after illness have not been examined in Ethiopia, and the existing literature suggests that these are clear data gaps. Some factors associated with poor linear growth in Ethiopia are missing in the framework, such as household characteristics (e.g. exposure to indoor smoke). Examination of the factors included in the WHO framework in a country setting helps identifying data gaps helping to target further data collection and research efforts. © 2016 John Wiley & Sons Ltd.

Lactic acid bacteria as a cell factory for the delivery of functional biomolecules and ingredients in cereal-based beverages: a review

In this review, we aim to describe the mechanisms by which LAB can fulfil the novel role of efficient cell factory for the production of functional biomolecules and food ingredients to enhance the quality of cereal-based beverages. LAB fermentation is a safe, economical, and traditional method of food preservation foremost, as well as having the additional benefits of flavor, texture, and nutrition amelioration. Additionally, LAB fermentation in known to render cereal-based foods and beverages safe, in a chemical-free, consumer-friendly manner, from an antinutrient and toxigenic perspective. Huge market opportunities and potential exist for food manufacturers who can provide the ideal functional beverage fulfilling consumer needs. Newly developed fermented cereal-based beverages must address markets globally including, high-nutrition markets (developing countries), lifestyle choice consumers (vegetarian, vegan, low-fat, low-salt, low-calorie), food-related non-communicable disease sufferers (cardiovascular disease, diabetes), and green label consumers (Western countries). To fulfil these recommendations, a suitable LAB starter culture and cereal-based raw materials must be developed. These strains would be suitable for the biopreservation of cereal beverages and, ideally, would be highly antifungal, anti-mycotoxigenic, mycotoxin-binding and proteolytic (neutralize toxic peptides and release flavor-contributing amino acids) with an ability to ferment cereals, whilst synthesizing oligosaccharides, thus presenting a major opportunity for the development of safe cereal-based prebiotic functional beverages to compete with and replace the existing dairy versions.