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Aflatoxin-lysine (AFB 1 -lys) adduct levels in blood samples collected from 230 individuals living in three districts of Malawi (Kasungu, Mchinji, and Nkhotakota) and aflatoxin B 1 (AFB 1 ) levels in groundnut and maize samples collected from their respective homesteads were determined using indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) methods. AFB 1 -lys adducts were detected in 67% of blood samples, with a mean concentration of 20.5 ± 23.4 pg/mg of albumin. AFB 1 was detected in 91% of groundnut samples and in 70% of maize samples, with mean AFB 1 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 AFB 1 -lys adduct levels in the blood. This is the first report on AFB 1 -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.

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.

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 B 1 (AFB 1 ) by competitive enzyme-linked immunosorbent assay (cELISA). Results showed substantial AFB 1 contamination levels in both types of groundnut products with maximum AFB 1 levels of 11,100 μg/kg (groundnut kernels) and 3000 μg/kg (milled groundnut powder). However, paired t test analysis showed that AFB 1 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, AFB 1 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 AFB 1 were found to be alarmingly high in all years and locations. Therefore, solutions are needed to reduce aflatoxin levels in such under-regulated markets.

This study assessed knowledge, attitude, and practices (KAP) of the public in Malawi on issues related to molds in foodstuffs. A survey involving structured questionnaire was conducted with 805 respondents from seven districts of Malawi. Descriptive statistics, t tests, and analyses of variance were calculated. A majority of respondents recognized that molds were dangerous to human health (88%); however, about 50% of respondents were not informed that mold toxins are thermally stable and that they are not destroyable by normal cooking processes. About 33% of the respondents asserted that they buy moldy maize, while approximately 20% of respondents reported that they consume moldy fruits having discarded moldy fraction. There were significant differences in knowledge scores among different demographic groups. Females had significantly (p < 0.05) lower knowledge scores on issues related to molds in foods. Additionally, the respondent's location had a significant effect. However, respondent's education had subtle effect on knowledge score and the overall population's knowledge score was generally low (3.55 ± 1.32 score out of 9). Results of the study underline the need to raise public's knowledge about health risks associated with spoilage molds in food and prevention and management options.

We report an unusual aflatoxin profile in maize and groundnuts from Malawi, with aflatoxin G1 found routinely at equal or even higher levels than aflatoxin B1. Aflatoxin B1 (AFB1) ratio in a contaminated sample is generally greater than 50% of total aflatoxin (sum of aflatoxin B1, B2, G1, and G2). In Malawi, the aflatoxin occurrence ratios were determined by examining LC-MS/MS and HPLC fluorescence detection (FLD) data of 156 naturally contaminated raw maize and 80 groundnut samples collected in 2011 and 2012. Results showed that natural aflatoxin occurrence ratio differed. In 47% of the samples, the concentration of AFG1 was higher than that of AFB1. The mean concentration percentages of AFB1/AFB2/AFG1/AFG2 in reference to total aflatoxins were found to be 47:5:43:5%, respectively. The AFG1 and AFB1 50/50 trend was observed in maize and groundnuts and was consistent for samples collected in both years. If the AFB1 measurement was used to check compliance of total aflatoxin regulatory limit set at 10, 20, 100, and 200 μg/kg with an assumption that AFB1≥50% of the total aflatoxin content, 8, 13, 24, and 26% false negative rates would have occurred respectively. It is therefore important for legislation to consider total aflatoxins rather than AFB1 alone.

Maize is one of the major staple foods of Sub-Saharan Africa and is consumed as whole or dehulled grain. In this region, where the environmental conditions favour fungal growth and mycotoxin production, the majority of the population are subsistence consumers who, unfortunately, have little or no access to mycotoxin testing of their food. In an attempt to develop feasible reduction strategies in dietary mycotoxin exposure of the population, a three-factorial design experiment was conducted to examine and compare the efficacy of hand sorting, flotation, dehulling and combinations thereof in removing naturally occurring aflatoxins, fumonisins, nivalenol, deoxynivalenol and alternariol in shelled white maize. Regression analysis was used to determine the significant (p < 0.05) process variables on the removal of mycotoxins from the maize. Results from this experiment indicated that hand sorting had the greatest effect on mycotoxin removal, while flotation yielded the least effect. In particular hand sorting left < 6% of aflatoxin B1 and < 5% of fumonisin B1. Based on these results, hand sorting of maize grains is being recommended as a last line of defence against mycotoxin exposure among subsistence consumers.

A 3-year comprehensive analysis of aflatoxin contamination in peanut butter was conducted in Zambia, sub-Saharan Africa. The study analyzed 954 containers of 24 local and imported peanut butter brands collected from shops in Chipata, Mambwe, Petauke, Katete, and Nyimba districts and also in Lusaka from 2012 to 2014. For analysis, a sample included six containers of a single brand, from the same processing batch number and the same shop. Each container was quantitatively analyzed for aflatoxin B1 (AFB1) in six replicates by using competitive enzyme-linked immunosorbent assay; thus, aflatoxin contamination level of a given sample was derived from an average of 36 test values. Results showed that 73% of the brands tested in 2012 were contaminated with AFB, levels >20 μg/kg and ranged up to 130 μg/kg. In 2013, 80% of the brands were contaminated with AFB1 levels >20 μg/kg and ranged up to 10,740 μg/kg. Compared with brand data from 2012 and 2013, fewer brands in 2014, i.e., 53%, had aflatoxin B, levels >20 μg/kg and ranged up to 1,000 μg/kg. Of the eight brands tested repeatedly across the 3-year period, none consistently averaged ≤20 μg/kg. Our survey clearly demonstrates the regular occurrence of high levels of AF B1 in peanut butter in Zambia. Considering that some of the brands tested originated from neighboring countries such as Malawi, Zimbabwe, and South Africa, the current findings provide a sub-Saharan regional perspective regarding the safety of peanut butter. [ABSTRACT FROM AUTHOR]

Abstract: Samples of locally (Malawian) processed and imported maize- and groundnut-based food products (peanut butters, roasted groundnuts, peanut based therapeutic foods, instant baby cereals, maize puffs and de-hulled maize flour) were collected from popular markets of Lilongwe City, Malawi. The samples were analysed in order to determine the frequency and extent of aflatoxin contamination, using immuno-affinity column and reversed-phase liquid chromatography with post-column photochemical derivatization and fluorescence detection. No aflatoxins were detected in all samples of imported baby cereal and locally processed de-hulled maize flour. However, all locally processed maize based baby foods had aflatoxins above EU maximum tolerable level of 0.1 μg/kg. In 75% of locally processed maize puffs, aflatoxins were detected at levels of up to 2 μg/kg. Peanut based therapeutic foods had aflatoxin level between 1.6 and 2.9 μg/kg, exceeding the EU tolerable maximum level (0.1 μg/kg) set for food for health purposes. Locally processed peanut butters had aflatoxins levels in the range of 34.2–115.6 μg/kg, which was significantly higher than their imported counterparts (<0.2–4.3 μg/kg). Samples of locally processed skinned and de-skinned roasted groundnuts had aflatoxins in range of 0.5–2.5 μg/kg and 0.6–36.9 μg/kg, respectively. These results highlight the need for rigorous monitoring of aflatoxins in commercially available processed products in order to reduce likely health risks associated with dietary aflatoxin intake. [Copyright &y& Elsevier]

[Display omitted] • Delphi method constructed consensus among experts on mycotoxin data descriptors. • Modularizing and organizing descriptors as a data submission template was relevant. • The proposed descriptors ensure harmonization of mycotoxins contamination data. • More descriptors identified in relation to pre and post-harvest practices of crops. 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. [ABSTRACT FROM AUTHOR]