Comparative utility of hermetic and conventional grain storage bags for smallholder farmers: a meta-analysis.

Postharvest management is critical to attaining household food, nutrition, and income security. Hermetic grain storage bags offer an effective pesticide-free way to protect stored grain against fungal and insect infestation. We evaluated articles indexed in the Web of Science that included experiments comparing the storage efficacy of conventional and hermetic storage bags based on grain germination rate, insect infestation, physical damage, mycotoxin contamination, and changes in weight and moisture content. Compared with grain stored in hermetic bags, grain stored in conventional bags lost 3.6-fold more seed viability, contained 42-fold more insects, had 11-fold more physical damage, and lost 23-fold more grain weight, while grain moisture levels were similar for both hermetic and conventional storage bags. Mycotoxin contamination levels were not as frequently assessed. Levels could be low in grain stored in both types of bags, or levels could be low in hermetic bags and significantly higher in conventional bags. The improved properties of grain stored in hermetic bags can increase food security and household income by providing safe storage options for maintaining seed germinability, and for consumption and/or sale when food supplies are high, or when prices are low. Hermetic bags are economically feasible for use by subsistence farmers in Sub-Saharan Africa for grain for household consumption and for carrying-over seed for planting in the next season. Additional studies are needed to verify the mycotoxin contamination results and to determine if there are differences in functional food characteristics, e.g. flavor and cooking properties, that have not been as comprehensively studied. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of dietary exposure and levels of mycotoxins in sorghum from Niger State of Nigeria.

This study reports levels of mycotoxins in sorghum from Niger State, Nigeria, and provides a comprehensive assessment of their potential health risks by combining mycotoxin levels and dietary exposure assessment. A total of 240 samples of red and white sorghum were collected from both stores and markets across four microclimatic zones. Fungal species were identified using a dilution plate method. Aflatoxins (AFs), deoxynivalenol, nivalenol, and ochratoxin (OTA) were quantified using HPLC, whereas cyclopiazonic acid, fumonisins (FUMs) and zearalenone were quantified using ELISA. A. flavus and A. fumigatus were dominant fungal species followed by F. verticilloides, A. oryzae and P. verrucosum. Aflatoxins (mean: 29.97 µg/kg) were detected in all samples, whereas OTA (mean: 37.5 µg/kg) and FUMs (mean: 3269.8 µg/kg) were detected in 72% and 50% of the samples, respectively. Mycotoxins frequently co-occurred in binary mixtures of AFs + OTA and AFs + FUMs. Dietary exposure estimates were highest for FUMs at 230% of TDI and margin of exposures (MOEs) for both AFs and OTA (<10,000) indicating a potential risk associated with combined exposure to AFs and OTA. The Risk of hepatocellular carcinoma cases (HCC/year) attributable to AFs and OTA exposure from sorghum was estimated to be 5.99 × 105 and 0.24 × 105 cases for HBsAg + individuals based on 13.6% HBV incidence. Similarly, the HCC/year for AFs and OTA were assessed to be 3.59 × 105 and 0.14 × 105 at an 8.1% prevalence rate. Therefore, the results of this study demonstrate the high prevalence and dietary exposure to mycotoxins through sorghum consumption, raising public health and trade concerns.

Hydrothermally-treated soybean-fortified maize-based nsima (stiff porridge) could contribute towards alleviating seasonal body weight loss in farming communities in sub-Saharan Africa.

Objective: This study explored the use of hydrothermally-treated soybean-fortified maize-based stiff porridge (nsima) in managing body weight losses among the farming family community in Malawi during the labour-intensive cropping (growing) season. We hypothesized that soybean-fortified maize-based nsima could prevent seasonal body weight losses in farming communities during labour-intensive seasons better than conventional 100% maize nsima. Research methods & procedures: A single-blind parallel dietary intervention 90-day study. During energy stress months, 42 farming households in Malawi were supplied with 15 kg of blind formulation of soybean-fortified maize flour (soybean: maize, 1:4, wt/wt) per person per month except for under-fives who were allotted half the quantity. Forty households were provided with equivalent quantities of 100% maize flour and served as control. Body weights of participants were taken at baseline and endpoint. Results: After 3 months, the experimental group registered 3.7, 4.2, 2.9, and 5.2% statistically higher body weight compared to the controls for the under-five, the 5-9-year-olds, the 10-19-year-olds, and the >20-year-olds, respectively. Conclusion: Soybean-fortified stiff porridge could feasibly be used to alleviate wasting among the resource-constraint populace in Malawi and many other parts of sub-Saharan Africa that rely on maize as a major staple.

Reduction of aflatoxins during brewing of a Malawian maize-based non-alcoholic beverage, thobwa.

This study reports onthe effect of various production steps on levels of aflatoxins during preparation of thobwa, a traditional maize-based fermented non-alcoholic beverage, brewed across Malawi. The effect of boiling, fermentation and their interaction on the level of aflatoxins, the trends of aflatoxin reduction during brewing, and the distribution of aflatoxins between the solid and liquid phases of the beverage were studied using VICAM AflaTest immunoaffinity fluorometric assay. Fermenting and boiling thobwa pre-mix-, with initial aflatoxin content of 45-183 µg/kg, resulted in aflatoxin reduction of 47% (13-61 µg/kg) on average. Fermentation and boiling contributed about 20 and 33% aflatoxin reduction, respectively, but without interactive effect between the two factors. Fermenting the thobwa for 24 h led to further reduction of aflatoxins to about 37% of the initial content, and remainedconstant for up to 8 days. Thobwa is a popular beverage in Malawi which is consumed in large quantities by all gender categories including infants, therefore the presence of aflatoxins may constitute a significant health risk factor. This study highlights the need to use raw materials with low levels of aflatoxins for production of maize-based non-alcoholic beverages to ensure consumer safety.

Collection of Data on Pesticides in Maize and Tomato in Africa: Protocol for Africa Pesticide Residue Survey Study.

Pesticide use has grown rapidly in West Africa over the past decades. Regulatory capacity has not kept pace with the rapid proliferation of pesticide products and on-farm use. As a result, health and environmental impacts from the growing use of pesticides, despite their potential importance to food safety, remain largely unmonitored, underreported, and poorly understood by key stakeholders. This study protocol was the document for conducting a pesticide survey study to identify the most critically emerging pesticides across the Continent of Africa. Multiple countries were selected in this study to represent the north, east, south, and west regions of Africa. Two food commodities, maize and tomato, were chosen to monitor the pesticide level for food safety. This study protocol describes the fieldwork and laboratory work per the standards of Good Laboratory Practices (GLP) and ISO-17025 and US EPA 860 Residue Chemistry Guidelines but the survey study performed was not considered as a GLP or ISO 17025 study. This is because many steps were not able to be closely monitored per the GLP requirements. This protocol describes the requirements for a pesticide residue study in food collected from local markets. This protocol describes the test commodities, sampling methods, sample transfer/shipping, storage stability, sample analysis, sample disposal, and documentation and record keeping.

Micro-climatic variations across Malawi have a greater influence on contamination of maize with aflatoxins than with fumonisins.

This study reports levels of aflatoxin and fumonisin in maize samples (n = 1294) from all agroecological zones (AEZs) in Malawi. Most maize samples (> 75%) were contaminated with aflatoxins and 45% with fumonisins, which co-occurred in 38% of the samples. Total aflatoxins varied across the AEZs, according to mean annual temperature (P < 0.05) of the AEZs. Samples from the lower Shire AEZ (median = 20.8 µg/kg) had higher levels of aflatoxins (P < 0.05) than those from the other AEZs (median = 3.0 µg/kg). Additionally, the majority (75%) of the positive samples from the lower Shire AEZ had aflatoxin levels exceeding the EU regulatory limit (4 µg/kg), whereas 25%, 37%, and 39% of positive samples exceeded the threshold in the mid-elevation, Lake Shore and upper and middle Shire, and highlands AEZs, respectively. The lower Shire AEZ is characterised by higher mean temperatures throughout the year and low erratic rainfall. However, total fumonisins did not show significant variation across AEZs, but all positive samples exceeded 150 µg/kg, required for tolerable daily intake of 1.0 µg/kg body weight per day, established by the European Food Safety Authority Panel on Contaminants in the Food Chain. Therefore, results of this study suggest that contamination of maize with aflatoxin responds to micro-climate more than with fumonisins. In addition, the data will be useful to public health policy-makers and stakeholders to articulate and implement monitoring and mitigation programs.

Mycotoxin levels and characterization of natural anti-fungal phytochemicals in pearl millet (Pennisetum glaucum) from Nigeria's six agroecological zones.

This study reports levels of multiple mycotoxins across Nigeria's six agro-ecological zones and corresponding levels of natural anti-fungal phytochemicals present in pearl millet (PM). 220 representative composite samples of PM were collected for mycotoxin analysis using ultrahigh performance liquid chromatography-mass spectrometry (UHPLC-MS), and 24 were randomly selected for determination of metabolites using gas chromatography-high resolution time of flight-mass spectrometry (GC-HRTOF-MS). In total, 15 mycotoxins were detected, all with levels below the European Union (EU) permissible limits and level of aflatoxins only up to 1.34 µg/kg. This is in sharp contrast to high levels of mycotoxins reported in maize samples from the same agroecological zones. Phytochemical analysis of the same samples identified a total of 88 metabolites, 30 of which are known anti-fungal properties from other previously published studies. The most common of these include methyl ester, bis (2-ethylhexyl) phthalate, and ç-tocopherol. The number of anti-fungal metabolites recovered from each sample ranged from 3 to 17 and varied widely in both number and composition across the agroecological zones. The anti-fungal metabolites may probably make PM less susceptible to fungal proliferation compared to other grains. Hence, it is worth exploring for possible sources of biological control products from PM.

Aflatoxin in cereals and groundnut from small holder farming households in Malawi.

Aflatoxin contamination in commonly consumed cereals and nuts may place children at higher risk of stunting and adults at risk of developing liver cancer. This study investigated knowledge on aflatoxins and the level of aflatoxin B1 contamination in commonly consumed cereals and nuts in Malawi. It also included an examination of the proportion of cereals and nuts contaminated above regulatory maximum limits. Aflatoxin contamination in samples was assessed using an enzyme-linked immunosorbent assay (ELISA) method. Less than half of all households knew that consumption of aflatoxin contaminated grain is associated with stunting and lowered immunity. Sorghum samples were the most contaminated and millet the least contaminated. Aflatoxin contamination was highest in southern Malawi and least in northern Malawi. Observed results indicate that this population is at risk of poor health due to lack of knowledge and aflatoxin exposure. Strategies to address contamination should therefore include a comprehensive education campaign to increase knowledge and promote accessible strategies.

Acceptability of orange corn-common bean as an alternative to corn-soybean complementary porridge in Malawi.

This study assessed the acceptability of porridge from a corn-common bean flour blend to increase the diversity of complementary foods in Malawi. Porridges prepared using commercial corn-soybean flour (C-CSB), homemade orange corn-soybean flour (H-CSB), and orange corn-common bean flour (CCBB) were evaluated by 101 pairs of mothers and their respective children aged from 6 to 24 months. A home use test (HUT) setup was used in this study, and the flours were given sequentially to participating households following a randomized complete block design. Each sample type was evaluated for 3 days in a row followed by a 1-day break (washout period) between sample types. Based on aggregate mean scores, all the samples were liked by both the children and their mothers. However, clustering results revealed two distinct consumer segments for mothers as well as for children. Most of the mothers (59.4% in cluster 1) liked all the samples, while the minority (cluster 2) were neutral (neither like nor dislike) regarding the H-CSB porridge. Likewise, most children (66.3% in cluster 2) liked all the samples, while the rest in cluster 1 did not like CCBB porridge. Infants (≤12 months) and those from food-insecure households, respectively, were 5.42 and 6.75 times more likely to like the CCBB porridge than their counterparts. The study has demonstrated the potential of introducing CCBB complementary porridge in Malawi and possibly in other countries with similar food preferences and socioeconomic stature. PRACTICAL APPLICATION: The study provides a solution to the limited diversity of complementary foods in sub-Saharan Africa and Malawi in particular. The findings can help food scientists, nutritionists, marketers, and policymakers develop strategies for promoting the consumption of orange corn-common bean porridge. Furthermore, the findings can inform decisions on commercializing orange corn-common bean flour by flour processors.

Essential descriptors for mycotoxin contamination data in food and feed.

Mycotoxin food contamination data is scattered, isolated, and poorly described. Reporting mycotoxin contamination data in a standardized manner is essential for collaborative research and integrated large-scale data analysis. The present study aimed to complement the existing European Food Safety Authority (EFSA) and Global Environment Monitoring System (GEMS) mycotoxin contamination data descriptors for application in low- and middle-income countries in particular. A three-round Delphi process was followed to establish a consensus on the missing descriptors. An invitation letter was first sent to 34 mycotoxin experts of an international collaboration of MYTOX-SOUTH®, of which 12 finally participated in the study. The response rate was 29.4% (10/34) in the Delphi I, 75% (9/12) in the Delphi II, and 83.3% (10/12) in the Delphi III rounds. The majority of the Delphi study participants were professors from 6 universities. Twenty-two descriptors (17 study level, 1 sample level, and 4 assay level) were proposed and were mainly related to pre and post-harvest periods of a food/feed sample. The pre-defined (>70% in the Delphi II and > 80% in the Delphi III) agreement among participants was achieved for all the proposed descriptors. The existing descriptors from EFSA (33) and GEMS (25) with the new proposed MYTOX-SOUTH® (22) descriptors, in total 80 descriptors, were arranged as study, sample, and assay categories and organized as a data submission template. Pre-testing of the template on three mycotoxin researchers indicated that the average time to fill out the form for a sample was 42 min. The current format helps mycotoxin contamination data to become more informative, reusable, and applicable especially to data from low- and middle-income countries. The above-proposed descriptors will help GEMS to provide technical cooperation with countries wishing to initiate and strengthen food contaminant monitoring programs. Similarly, the descriptors from the current study will be useful for EFSA as it regularly updates the Standard Sample Description. A standardized global reporting format for mycotoxin contamination data will enable national authorities to perform mycotoxins exposure and risk assessments and share data for international benchmarking. Standardized reporting and sharing of mycotoxin contamination data should be further advocated in ongoing research and become common practice in authorities, companies, academia, and other entities working on mycotoxin in food and feed.

A concise review towards defining the exposome of oesophageal cancer in sub-Saharan Africa.

CONTEXT: Oesophageal cancer (EC) is among the common causes of illness and death among all cancers worldwide. Advanced EC has a poor prognosis, with worse outcomes observed in low-income settings. Oesophageal squamous cell carcinoma (ESCC) is the most common EC histology reported globally, with the highest ESCC incidence rates in the 'Asian Belt' and the African EC corridor. While the aetiology of ESCC is well-documented in the 'Asian belt', data for the African EC corridor and the entirety of sub-Saharan Africa (SSA) are fewer. OBJECTIVE: To help address gaps in ESCC aetiology in SSA, we critically evaluated evidence of lifestyle, environmental, and epigenetic factors associated with ESCC risk and discussed prospects of defining ESCC exposome. DATA INCLUSION: Unlimited English and non-English articles search were made on PubMed Central and Web of Science databases from January 1970 to August 2021. In total, we retrieved 999 articles and considered meta-analyses, case-control, and cohort studies. The quality of individual studies was assessed using the Newcastle-Ottawa scale. DATA EXTRACTION: Details extracted include the year of publication, country of origin, sample size, comparators, outcomes, study subjects, and designs. DATA ANALYSIS: Together, we assessed 13 case-control studies and two meta-analyses for the effect of lifestyle or environmental exposures on ESCC risk. Again, we evaluated seven case-control studies and one meta-analysis regarding the role of epigenetics in ESCC tumorigenesis. RESULTS: In general, evidence of ESCC aetiology points to essential contributions of alcohol, tobacco, hot beverages, biomass fuel, and poor oral health/hygiene, although more precise risk characterisation remains necessary. CONCLUSION: We conclude that ESCC in SSA is a multifactorial disease initiated by several external exposures that may induce aberrant epigenetic changes. The expanding aetiological research in this domain will be enhanced by evidence synthesis from classical and molecular epidemiological studies spanning the external and internal exposome.

Aflatoxin M1 in raw cow milk and associated hepatocellular carcinoma risk among dairy farming households in Malawi.

In the present study, a total of 112 raw milk samples were collected between October and December of 2018 from dairy farming households in Malawi and analyzed for aflatoxin M1 (AFM1) using VICAM aflatest fluorometry procedure. These data together with the consumption data obtained through a milk consumption frequency questionnaire were used for the calculation of AFM1 exposure and its association with hepatocarcinoma (HCC) risk in dairy farming population. Average daily milk intake by children and adults were approximately 300 ± 0.07 and 541.7 ± 0.14 mL, respectively. All raw milk samples tested positive to AFM1 averaging 0.551 µg/L. Probable mean daily exposure to AFM1 for adults was 4.98 ± 7.25 ng/kg BW/day almost half that of children (8.28 ± 11.82 ng/kg BW/day). Estimated risk of AFM1-induced HCC associated with consumption of milk among children and adults were 0.038 and 0.023 cases per 100,000 individuals per year, respectively. Although the results of this investigation suggest a low risk of HCC, other negative health effects of AFM1 justify its continuous monitoring and update of the risk assessment. This work presents the first insight in the occurrence of AFM1 in cow milk in Malawi as well as associated AFM1 exposure in dairy farming population.

Hydrothermally Treated Soybeans Can Enrich Maize Stiff Porridge (Africa's Main Staple) without Negating Sensory Acceptability.

Maize-based stiff porridge, a starchy protein-deficient staple food, dominates among the populations in sub-Saharan Africa (SSA). Unfortunately, this is often consumed along with leafy vegetables since the majority of the population in this region lack resources for the purchase of high protein animal source foods, a situation that exacerbates protein-energy malnutrition. Considering this, the current study evaluated the effect of enriching maize-based stiff porridge with flour made from hydrothermally treated soybeans on consumer acceptability. A total of nine experimental flours were prepared from maize and maize-soybean mixtures following a 32 factorial design involving two factors, namely maize flour type (whole maize, non-soaked dehulled maize, and soaked dehulled maize) and soybean flour proportion (0%, 20%, and 30%). A total of 125 adult consumers from a rural setting in Malawi evaluated maize-based stiff porridges made thereof using a 7-point hedonic scale. Subsequently, the participants were asked to guess an ingredient that was added to some of the test samples. The 10% and 20% soybean-enriched maize-based stiff porridges scored 5/7 and above, with some being statistically similar to plain maize-based stiff porridges. No participant recognized that soybeans were incorporated into the maize-based stiff porridges. The study has clearly demonstrated the potential of enriching maize-based stiff porridge with hydrothermally treated soybeans without compromising consumer acceptability. This innovation could significantly contribute towards reducing the burden of energy-protein under-nutrition in SSA.

Tackling protein-energy under-nutrition among resource-limited people living with HIV/AIDS in Malawi using soybean-enriched maize-based stiff porridge (nsima): A pilot study.

AIM: The Ministry of Health in Malawi has scaled-up antiretroviral therapy (ART) for HIV infection. However, the majority of Malawians heavily depend on maize-based stiff porridge (nsima), a protein-deficient staple, a practice that exacerbates wasting and ultimately compromises the success of ART programming. This pilot study was conducted to evaluate the efficacy of utilising soybean-enriched nsima as a strategy for managing HIV-related wasting among resource-poor people. METHODS: A before and after designed study involving 25 wasted (<18.5 BMI (body mass index)) to normal (18.5-24.9 BMI) HIV-positive rural women (21-40 years) taking ART and provided with soybean-maize flour (20 kg/month for 3 months) prepared from hydrothermally treated soybeans and maize in the ratio of 1:4 (wt/wt). Anthropometry was performed at baseline and every month for the 3-month study period. Paired sample t-tests were used to test for changes in body mass and BMI between baseline and the subsequent months. RESULTS: Statistically significant (P < 0.001) cumulative mean weight gain for the first, second and third month of the study were 1.6, 2.1 and 2.9 kg, respectively. The number of participants with low BMI reduced from 6/25 at baseline to 2/25 after 3 months, and the mean BMI improved from 19.3 to 21.1 kg/m2 . CONCLUSIONS: Nsima prepared from a blend of maize and hydrothermally treated soybeans could feasibly be used to prevent and manage wasting among resource-poor people living with HIV/AIDS in sub-Saharan Africa who rely on maize as a major staple.

Consumption of illegal home-made alcohol in Malawi: A neglected public health threat.

This study assessed the ethanol and methanol contents of homemade spirit (Kachasu) sold in Blantyre, Malawi. The likelihood of ethanol and methanol toxicity, respectively, was determined through Monte Carlo simulations using reported Kachasu intake volumes of 21 consumers and the determined methanol and ethanol contents. Ethanol concentration, in samples from 20 different distillers, ranged from 11 to 55% v/v. Methanol was detected in 10 of the 20 samples (0.01-0.28% v/v). The likely mean ethanol intake of drinkers in Blantyre was found to be 214 ± 93 mL per day (90% CI, 68.9-373.4 mL), and mean methanol intake was 0.44 ± 0.37 mL (90% CI, 0.03-1.17 mL). The intake values translated to mean blood ethanol and methanol concentrations of 38 ± 16 mg/mL and 0.05 ± 0.04 mg/mL, respectively. Therefore, the risk of methanol toxicity was considered as negligible. However, there was a high risk of ethanol toxicity. Since production and selling of Kachasu are already illegal in Malawi, enforcement of regulations should be strengthened to reverse the current situation where Kachasu is being distilled and sold openly even within cities. Consumers should also be sensitized about the likely risks associated with consumption of Kachasu in Malawi so that they can make informed choices.

Aflatoxin-lysine adducts in blood serum of the Malawian rural population and aflatoxin contamination in foods (groundnuts, maize) in the corresponding areas.

Aflatoxin-lysine (AFB1-lys) adduct levels in blood samples collected from 230 individuals living in three districts of Malawi (Kasungu, Mchinji, and Nkhotakota) and aflatoxin B1 (AFB1) levels in groundnut and maize samples collected from their respective homesteads were determined using indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) methods. AFB1-lys adducts were detected in 67% of blood samples, with a mean concentration of 20.5 ± 23.4 pg/mg of albumin. AFB1 was detected in 91% of groundnut samples and in 70% of maize samples, with mean AFB1 levels of 52.4 and 16.3 µg/kg, respectively. All participants of this study reported consuming maize on a daily basis and consuming groundnuts regularly (mean consumption frequency per week: 3.2 ± 1.7). According to regression analysis, a frequency of groundnut consumption of more than four times per week, being female, and being a farmer were significant (p < 0.05) contributors to elevated AFB1-lys adduct levels in the blood. This is the first report on AFB1-lys adducts in blood samples of residents in Malawi. The results reinforce the urgent need for interventions, aiming at a reduction of aflatoxin exposure of the population.

Aflatoxins, discolouration and insect damage in dried cowpea and pigeon pea in Malawi and the effectiveness of flotation/washing operation in eliminating the aflatoxins.

Aflatoxin contamination and biodeterioration were examined in 302 samples of dry cowpeas and pigeon peas that were randomly purchased from 9 districts of the Southern Region of Malawi during July and November 2015. Further, the impact of flotation/washing on aflatoxin levels on the pulses was elucidated. Aflatoxin analyses involved immunoaffinity column (IAC) clean-up and HPLC quantification with fluorescence detection (FLD) while legume biodeterioration assessments were done by visual inspection. Aflatoxins were frequently detected in cowpea (24%, max., 66 µg/kg) and pigeon pea (22%, max., 80 µg/kg) samples that were collected in the month of July. Lower aflatoxin incidence of 15% in cowpeas (max., 470 µg/kg) and 14% in pigeon peas (max., 377 µg/kg) was recorded in the November collection. Overall, aflatoxin levels were significantly higher in the pulses that were collected in November. However, there were no significant differences in the total aflatoxin (aflatoxin B1 (AFB1) + AFB2 + AFG1 + AFG2) levels between the two types of pulses. Remarkably, in 76.2% of the aflatoxin positive cowpea and in 41.7% of the aflatoxin positive pigeon pea samples, aflatoxin G1 concentration exceeded aflatoxin B1. Insect damage percentage averaged at 18.1 ± 18.2% (mean ± SD) in the cowpeas and 16.1 ± 19.4% in pigeon peas. Mean discolouration percentage (number of pulses) of the cowpeas and pigeon peas was found to be at 6.7 ± 4.9 and 8.7 ± 6.2%, respectively. Washing and discarding the buoyant fraction was highly efficient in reducing aflatoxin levels; only 5.2 ± 11.1% of the initial aflatoxin level was found in the cleaned samples. In conclusion, cowpeas and pigeon peas sold on the local market in Malawi may constitute a hazard especially if floatation/washing step is skipped.

Aflatoxin B1 levels in groundnut products from local markets in Zambia.

In Zambia, groundnut products (milled groundnut powder, groundnut kernels) are mostly sold in under-regulated markets. Coupled with the lack of quality enforcement in such markets, consumers may be at risk to aflatoxin exposure. However, the level of aflatoxin contamination in these products is not known. Compared to groundnut kernels, milled groundnut powder obscures visual indicators of aflatoxin contamination in groundnuts such as moldiness, discoloration, insect damage or kernel damage. A survey was therefore conducted from 2012 to 2014, to estimate and compare aflatoxin levels in these products (n = 202), purchased from markets in important groundnut growing districts and in urban areas. Samples of whole groundnut kernels (n = 163) and milled groundnut powder (n = 39) were analysed for aflatoxin B1 (AFB1) by competitive enzyme-linked immunosorbent assay (cELISA). Results showed substantial AFB1 contamination levels in both types of groundnut products with maximum AFB1 levels of 11,100 µg/kg (groundnut kernels) and 3000 µg/kg (milled groundnut powder). However, paired t test analysis showed that AFB1 contamination levels in milled groundnut powder were not always significantly higher (P > 0.05) than those in groundnut kernels. Even for products from the same vendor, AFB1 levels were not consistently higher in milled groundnut powder than in whole groundnut kernels. This suggests that vendors do not systematically sort out whole groundnut kernels of visually poor quality for milling. However, the overall contamination levels of groundnut products with AFB1 were found to be alarmingly high in all years and locations. Therefore, solutions are needed to reduce aflatoxin levels in such under-regulated markets.

Keeping mycotoxins away from the food: Does the existence of regulations have any impact in Africa?

Following the discovery of aflatoxins in the early 1960s, there have been many studies leading to the uncovering of many mycotoxins and the understanding of associated health effects in animals and humans. Consequently, there has been a global increase in the number of countries with mycotoxin regulations in foods. However, many African countries have only regulations for aflatoxins (or a few other mycotoxins) in specific foods, or no regulations at all. This paper critically reviews the challenges thwarting the establishment of mycotoxin regulations and their impacts on human dietary mycotoxin exposure in Africa. Mycotoxin regulatory limits for different countries are compared with mycotoxin tolerable daily intakes established by international food safety bodies taking into account consumption patterns. The agrarian setup, food insecurity, and mycotoxin analytical challenges in African countries are discussed; and more feasible mycotoxin dietary exposure reduction strategies are proposed.