Aflatoxin contamination of various staple foods from Angola and Mozambique

Citation: Matusse, C.; Lucamba, Z.; Bila, J.; Macuamule, C.; Sampaio, A.; Afonso, S.; Venâncio, A.; Rodrigues, P. Aflatoxin Contamination of Various Staple Foods from Angola and Mozambique. Toxins 2024,16, 516. https://doi.org/10.3390/ toxins16120516 Received: 8 November 2024 Revised: 22 November 2024 Accepted: 27 November 2024 Published: 29 November 2024 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Article Aflatoxin Contamination of Various Staple Foods from Angola and Mozambique Cláudio Matusse 1,2,3, Zelda Lucamba 4, João Bila 5,6 , Custódia Macuamule 7, Ana Sampaio 3,8,9 , Sandra Afonso 4,10, Armando Venâncio 11,12 and Paula Rodrigues 1,* 1 CIMO, LA SusTEC, Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal; [email protected] 2 Department of Agriculture, College of Business and Entrepreneurship of Chibuto, UEM-Eduardo Mondlane University, Gaza 1200, Mozambique 3University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal; [email protected] 4Instituto Superior Politécnico de Cuanza Sul, Rua 12 de Novembro, Sumbe, Cuanza Sul CP 82, Angola; [email protected] (Z.L.); [email protected] (S.A.) 5Department of Crop Protection, Faculty of Agronomy and Forestry Engineering, UEM-Eduardo Mondlane University, Maputo 1102, Mozambique; [email protected] 6Centre of Excellence in Agri-Food Systems and Nutrition (CE-AFSN), UEM-Eduardo Mondlane University, Maputo 1102, Mozambique 7Department of Animal Production and Food Technology, Faculty of Veterinary, UEM-Eduardo Mondlane University, Maputo 1102, Mozambique; [email protected] 8 Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD) Quinta de Prados, 5000-801 Vila Real, Portugal 9Laboratório Associado Instituto Para a Inovação, Capacitação e Sustentabilidade da Produção Agroalimentar (Inov4Agro), University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal 10 Centro Nacional de Investigação Científica, Rua Avenida Ho Chi Minh, 201, Maianga, Luanda CP 34, Angola 11 CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; [email protected] 12 LABBELS—Associate Laboratory, 4800-058 Guimarães, Portugal *Correspondence: pr[email protected] Abstract: Aflatoxins constitute a significant risk in staple foods produced in African countries. This research aimed to analyze the total aflatoxin (AFT) contamination of various staple foods in Angola and Mozambique. A total of 233 samples of corn, peanuts, beans, rice, and cassava flour collected from farmers or local markets from the province of Cuanza Sul, Angola, and the provinces of Gaza and Inhambane, South Mozambique, were analyzed for the presence of AFT using the lateral flow strip method via AgraStrip ® Pro WATEX ® (Romer). The results showed that, from all matrices, the highest incidence and level of AFT were found in corn produced in Mozambique, with medians ranging from 6.5 to 66.5 µ g/kg, with the samples showing values as high as 9200 µ g/kg. Levels higher than the maximum admissible levels recommended by the Codex Alimentarius Commission for cereals and pulses (15 µ g/kg) were observed in up to 90% of the corn samples, depending on the province. Corn produced in Angola showed lower amounts of AFT, with medians ranging from 1.2 to 7.7 µg/kg. Considering the maximum admissible levels for AFT recommended by the European Commission and the Codex Alimentarius Commission for cereals and pulses, the level of AFT contamination in staple food produced and consumed in the studied provinces is high and constitutes a public health risk for the population. Therefore, risk mitigation strategies are urgently needed. Keywords: toxicity; mycotoxins; food security; quality control; Africa Key Contribution: Our results showed a high level of AFT contamination in Mozambique and Angola’s main staple foods. Mycotoxin occurrence data from Mozambique are scarce, while for Angola, this is the first report on AF occurrence. Toxins 2024,16, 516. https://doi.org/10.3390/toxins16120516 https://www.mdpi.com/journal/toxins Toxins 2024,16, 516 2 of 16 1. Introduction Aflatoxins (AFs) are considered the most harmful mycotoxins [ 1 ], and aflatoxin B1 (AFB1) in particular has been classified into Group 1 “carcinogenic to humans” by the International Agency for Research on Cancer [ 2 ]. Acute exposure to high doses can cause vomiting and abdominal pain, and, in extreme situations, it can be lethal, while chronic exposure at lower doses is associated with liver cancer [ 3 ]. Aflatoxins are among the most common mycotoxins in agriculturally important food crops worldwide. They thus constitute a major risk to human and animal health. Aflatoxins contaminate many agricultural products, which are particularly susceptible to being infested by aflatoxigenic fungi [ 4 ]. Corn, peanuts, rice, sorghum, and wheat are each responsible for more than 10% of the global exposure to AFs [ 5 ]. Poor hygiene during transport and storage, high temperatures and relative humidity, and heavy rainfall are all conditions that favor fungal growth and potentiate AF production [ 6 ]. The populations in any region or country where these conditions are found are more susceptible to mycotoxin exposure. In general, these regions also face higher malnutrition and food insecurity problems, and there are few regulatory instruments that can protect the exposed and vulnerable populations. African countries, particularly those belonging to the Southern African Development Community (SADC), are considered highly vulnerable to AF exposure. In such countries, corn and peanuts are base staple crops for most of the population and constitute the major source of AF intake for these populations. Despite this predicted high susceptibility, only a few countries in this region, as is the case for South Africa and Tanzania, have been subject to considerable research on AF incidence in their agricultural products, and the characterization of AF exposure in other countries in this region is scarce. Angola and Mozambique are SADC countries with little or no knowledge of their staple foods’ AF incidence and contamination levels. Only a few reports are available from Mozambique, and, to our knowledge, none are available from Angola. In Mozambique, AF contamination has been reported for corn [7–10], peanuts [8,11,12], and cashew nuts [13]. The maximum tolerable limit (MTL) of AFs regulated by the European Union (MTLEU) in peanuts and other oilseeds used as the only ingredient; products processed from peanuts; cereals; and products derived from cereals is very low: 4 µ g/kg [ 14 ]. The AF MTL stipulated by the Food and Agriculture Organization (FAO) and Codex Alimentarius (MTLCodex) for African countries is, on the other hand, less stringent: 10 µ g/kg for peanuts, beans, cassava, and rice, and 15 µ g/kg for corn [ 15 ]. In Mozambique, MTLs are established for peanuts only, at 10 µ g/kg, and Angola has no established MTLs [ 15 ]. African countries have the sovereignty and right to apply the codex regulations for quality control and food safety (specifically mycotoxins). Still, exportation to Europe requires adopting European legislation, which can generate solid commercial constraints. Narayan et al. [ 16 ] reported that in Tanzania and Nigeria, two countries highly affected by AF contamination [ 17 ], this was not a critical factor in peanuts and corn exports since the high domestic demand for these products resulted in negligible amounts being released for exportation. The same occurs in Angola and Mozambique, particularly in rural areas, where the trade of these staples is residual and they are mainly produced for family consumption or local trade. This contributes to the domestic consumption of highly contaminated products, making these populations even more susceptible to high AF intake. Agriculture is a fundamental activity affecting most families in both Angola and Mozambique. Family farms constitute around 98% of all farms, and 60 to 75% of the population depends on agriculture for survival [ 18 , 19 ]. It is estimated that there are 2.3 million and 4.2 million family farms in Angola and Mozambique, respectively [ 18 , 19 ]. Staple foods like corn, peanuts, rice, cassava, and beans are not only the basis of family nutrition in these countries; they are also sources of economic income, mainly resulting from local formal or informal trade. In Angola, the province of Cuanza Sul has the thirdlargest farming area and the third-highest number of farms in the country, and 97% of the families depend on agriculture [ 19 ]. In this province, the most significant crops are Toxins 2024,16, 516 3 of 16 corn, produced on 95% of the farms, cassava (57%), and beans (56%), followed by peanuts (36%) [ 19 ]. In Mozambique, a significant number of farms produce corn (83.8%), peanuts (23.6%), and rice (12.8%) [ 18 ], and the south provinces of Gaza and Inhambane also depend on these staples. Gaza is the country’s third largest producer of corn and rice, while the province of Inhambane is a significant peanuts producer. Despite the importance of agricultural production, Mozambique suffers from one of the highest malnutrition rates in the world, especially in rural areas [ 20 ]. In 2019, almost 30% of the families faced acute food insecurity; in comparison, 16% was reported in 2016 [ 21 ]. In 2019, the provinces of Gaza and Inhambane registered the highest levels of acute food insecurity in the country, with 48% and 40% of families facing this problem, numbers that can be compared against the values of 39% and 20% registered in 2016 [ 21 ]. In Angola, the level of food insecurity is also alarming, and malnutrition is a public health issue affecting almost half of the population, with around 1.58 million people suffering from acute severe food insecurity [22]. Post-harvest food losses, including those resulting from fungal growth and mycotoxin accumulation, are among the most important causes of food insecurity and malnutrition in these countries [ 23 ]. MADER [ 18 ] estimates that corn losses in the provinces of Maputo and Inhambane, Mozambique, reach as high as 29.4% and 26% of the production, respectively, thus strongly contributing to food supply shortages. Also, AF exposure among young children is correlated with impaired growth and stunting [ 3 ] and strongly correlated with hepatocellular cancer [ 24 ]. The adoption of strategies for mitigating AF contamination in food is thus fundamental for food security, public health, and commercial reasons and will aid in reducing extreme food insecurity situations. This study aimed to analyze the total AF contamination levels of various staple foods produced by small-scale and subsistence farmers in rural settings of the province of Cuanza Sul, Angola, and the provinces of Gaza and Inhambane, South Mozambique, to understand the extent to which AFs pose a risk in these two countries. To the best of the authors’ knowledge, this is the first report on AF contamination of foods from Angola. 2. Results This work looked at the incidence of total aflatoxin (AFT) contamination in various staple foods—corn, peanuts, beans, rice and cassava flour—produced in the province of Cuanza Sul (five districts), Angola, and in the provinces of Gaza (three districts) and Inhambane (three districts), South Mozambique. The overall occurrence and average, median, and range (min and max) levels of AFT are reported in Table 1. Table 2provides a detailed description of the incidence and levels of AFT contamination by country, province, district, and product, as well as the percentage of samples exceeding the maximum tolerable limits set by the European Union (MTL-EU) and the Codex Alimentarius (MTL-Codex). Figure 1 reports the distribution of samples (in percentages) according to class of contamination. Table 1. Overall results for total aflatoxin contamination of samples from Angola and Mozambique, arranged by product. NPositives (%) Average of All Samples (µg/kg) Median (µg/kg) Range (µg/kg) Corn Mozambique 30 100 1107.6 26.9 <LOQ—9200 Angola 48 96 5.1 1.7 <LOD—82.3 Total 78 97 429.1 2.0 <LOD—9200 Toxins 2024,16, 516 4 of 16 Table 1. Cont. NPositives (%) Average of All Samples (µg/kg) Median (µg/kg) Range (µg/kg) Peanuts Mozambique 50 36 40.6 <LOD <LOD—496 Angola 15 47 8.3 <LOD <LOD—52.3 Total 65 39 33.2 <LOD <LOD—496 Cassava Mozambique 30 37 1.5 <LOD <LOD—9.6 Angola 10 0 <LOD - <LOD Total 40 28 1.3 <LOD <LOD—9.6 Beans Mozambique - - - - - Angola 20 25 <LOD <LOD <LOD—2.9 Total 20 40 <LOD <LOD <LOD—2.9 Rice Mozambique 30 70 23.1 1.8 <LOD—380 Angola - - - - - Total 30 70 23.1 1.8 <LOD—380 All samples Mozambique 140 57 257.1 1.7 <LOD—9200 Angola 93 62 4.3 1.3 <LOD—82.3 Total 233 59 156.2 1.5 <LOD—9200 Toxins 2024, 16, x FOR PEER REVIEW 4 of 17 Table 1. Overall results for total aflatoxin contamination of samples from Angola and Mozambique, arranged by product. N Positives (%) Average of All Samples (µg/kg) Median (µg/kg) Range (µg/kg) Corn Mozambique 30 100 1107.6 26.9 <LOQ—9200 Angola 48 96 5.1 1.7 <LOD—82.3 Total 78 97 429.1 2.0 <LOD—9200 Peanuts Mozambique 50 36 40.6 <LOD <LOD—496 Angola 15 47 8.3 <LOD <LOD—52.3 Total 65 39 33.2 <LOD <LOD—496 Cassava Mozambique 30 37 1.5 <LOD <LOD—9.6 Angola 10 0 <LOD - <LOD Total 40 28 1.3 <LOD <LOD—9.6 Beans Mozambique - - - - - Angola 20 25 <LOD <LOD <LOD—2.9 Total 20 40 <LOD <LOD <LOD—2.9 Rice Mozambique 30 70 23.1 1.8 <LOD—380 Angola - - - - - Total 30 70 23.1 1.8 <LOD—380 All samples Mozambique 140 57 257.1 1.7 <LOD—9200 Angola 93 62 4.3 1.3 <LOD—82.3 Total 233 59 156.2 1.5 <LOD—9200 Figure 1. Distribution of samples (as percentages) according to level of contamination. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Beans Cassava flour Peanuts Corn Total Rice Cassava flour Peanuts Corn Total Angola Mozambique < LOD LOD – LOQ LOQ – 4 µg/kg 4 – 15 µg/kg 15 – 50 µg/kg 50 – 100 µg/kg > 100 µg/kg Figure 1. Distribution of samples (as percentages) according to level of contamination. Toxins 2024,16, 516 5 of 16 Table 2. Detailed description of the incidence and levels of total aflatoxin contamination in Angola and Mozambique according to country, province, district, and product. Colors represent the level of contamination, ranging from lowest (green) to highest (red). Country Province District Product Total Samples (n) Positive Samples (n) Positive Samples (%) Average of All Samples (µg/kg) Average of Positive Samples (µg/kg) Median of All Samples (µg/kg) Median of Positives Samples (µg/kg) Min (µg/kg) Max (µg/kg) Samples > MTL Codex (%) Samples > MTL EU (%) Angola Cuanza Sul Cassongue Corn 10 9 90 1.5 1.6 1.7 1.7 1.0 1.9 0.0 0.0 Peanuts 5 3 60 1.3 1.3 1.2 1.2 1.0 1.8 0.0 0.0 Ebo Corn 10 9 90 1.5 1.5 1.5 1.5 1.0 2.0 0.0 0.0 Quibala Corn 10 10 100 1.5 1.5 1.5 1.5 1.0 2.0 0.0 0.0 Seles Corn 8 8 100 1.9 1.9 2.0 2.0 1.3 2.4 0.0 0.0 Sumbe Corn 10 10 100 18.6 18.6 7.7 7.7 1.4 82.3 50.0 60.0 Beans 20 5 25 1.0 2.3 0.5 1.9 1.6 2.9 0.0 0.0 Cassava flour 10 0 0 <LOD <LOD <LOD <LOD <LOD <LOD 0.0 0.0 Peanuts 10 4 40 11.7 28.2 0.8 29.2 2.2 52.3 20.0 30.0 Mozambique Gaza Chokwe Corn 10 10 100 1972.6 1972.6 66.5 66.5 1.3 9200.0 80.0 80.0 Rice 10 9 90 4.9 5.3 2.1 2.2 1.0 25.2 10.0 10.0 Manjacaze Corn 10 10 100 369.2 369.2 40.0 40.0 4.8 1950.0 90.0 100.0 Peanuts 10 2 20 5.8 26.0 0.8 26.0 10.6 41.3 20.0 20.0 Rice 10 9 90 63.1 70.0 17.3 23.7 1.4 380.0 60.0 60.0 Chongoene Corn 10 10 100 981.1 981.1 5.8 5.8 2.4 8736.0 30.0 90.0 Peanuts 10 5 50 5.6 10.5 1.3 2.3 1.8 43.6 10.0 10.0 Rice 10 3 30 1.2 2.9 0.5 1.7 1.1 6.0 10.0 10.0 Inhambane Jangamo Peanuts 10 4 40 95.5 237.6 0.8 235.5 12.6 467.0 40.0 40.0 Cassava flour 10 2 20 0.9 1.7 0.8 1.7 1.6 1.7 0.0 0.0 Inharrime Peanuts 10 2 20 4.8 20.9 0.8 20.9 12.6 29.1 20.0 20.0 Cassava flour 10 2 20 1.0 2.1 0.8 2.1 1.8 2.3 0.0 0.0 Massinga Peanuts 10 5 50 91.4 182.1 2.1 173.0 3.5 496.0 40.0 40.0 Cassava flour 10 7 70 2.6 3.3 2.2 2.5 1.7 9.6 0.0 10.0 Toxins 2024,16, 516 6 of 16 Overall, the results show that AFTs were detected in all the analyzed crops, except cassava from Angola, where no contamination was detected (Table 1). Disregarding the origin of the samples, corn was the crop with the highest incidence and level of contamination, followed by peanuts and rice. Beans and cassava flour were the least contaminated products. 2.1. Incidence of Total Aflatoxins in Angola In Angola, AFT contamination was noted in all the matrices studied except cassava flour (Table 1; Figure 1), with 58 out of the total 93 samples (62%) showing detectable AFs. However, only corn and peanuts showed levels of contamination above those permitted by the European Union (MTL-EU) and the Codex (MTL-Codex) (Table 2). While corn showed a higher incidence than peanuts (96% and 47%, respectively), peanuts showed a higher average of contamination (8.3 µ g/kg against 5.1 µ g/kg) (Table 1; Figure 2) and a higher percentage of samples exceeding the MTLs (Table 2). The incidence of AFTs in corn produced in Angola was very high and ranged from 90% to 100% in the positive (>LOD) samples. Toxins 2024, 16, x FOR PEER REVIEW 6 of 17 2.1. Incidence of Total Aflatoxins in Angola In Angola, AFT contamination was noted in all the matrices studied except cassava flour (Table 1; Figure 1), with 58 out of the total 93 samples (62%) showing detectable AFs. However, only corn and peanuts showed levels of contamination above those permitted by the European Union (MTL-EU) and the Codex (MTL-Codex) (Table 2). While corn showed a higher incidence than peanuts (96% and 47%, respectively), peanuts showed a higher average of contamination (8.3 µg/kg against 5.1 µg/kg) (Table 1; Figure 2) and a higher percentage of samples exceeding the MTLs (Table 2). The incidence of AFTs in corn produced in Angola was very high and ranged from 90% to 100% in the positive (>LOD) samples. Figure 2. Boxplot of the average total aflatoxin concentration (1 + log10 µg/kg) in various Angolan staple foods. The bars represent the minimum and maximum intervals; different letters highlight significant differences (p < 0.05) between the matrices according to the Kruskal–Wallis test, followed by Dunn’s multiple comparison. The district of Sumbe showed the highest AFT levels, with 60% and 50% of the corn samples collected there exceeding the MTL-EU (4 µg/kg) and the MTL-Codex (15 µg/kg) levels, respectively, with a maximum amount of 82.3 µg/kg (Table 2; Figure 1). AFT levels of corn in this district were significantly higher than in the remaining districts (p < 0.046), where the maximum levels ranged from 1.9 to 2.4 µg/kg (Figure 3) and none of the samples exceeded the MTLs. Also, in the district of Sumbe, peanuts samples exceeded the MTL-EU (4 µg/kg) and MTL-Codex (10 µg/kg) levels by around 30% and 20%, respectively, with the maximum level of AFs being 52.3 µg/kg (Table 2; Figure 3). The highest levels of contamination in the district of Sumbe may result from the samples having been collected from local markets, without knowledge of the time and conditions of storage of the products. For the remaining districts, samples were collected from the producers, either from a field or storage house. Beans and cassava flour were the least contaminated products in the province in terms of AF incidence and concentration. None of the samples reached the MTLs. Beans Cassava flour Corn Peanuts 0.0 0.5 1.0 1.5 2.0 2.5 a b a b b Figure 2. Boxplot of the average total aflatoxin concentration (1 + log10 µ g/kg) in various Angolan staple foods. The bars represent the minimum and maximum intervals; different letters highlight significant differences (p< 0.05) between the matrices according to the Kruskal–Wallis test, followed by Dunn’s multiple comparison. The district of Sumbe showed the highest AFT levels, with 60% and 50% of the corn samples collected there exceeding the MTL-EU (4 µg/kg) and the MTL-Codex (15 µg/kg) levels, respectively, with a maximum amount of 82.3 µ g/kg (Table 2; Figure 1). AFT levels of corn in this district were significantly higher than in the remaining districts (p< 0.046), where the maximum levels ranged from 1.9 to 2.4 µ g/kg (Figure 3) and none of the samples exceeded the MTLs. Also, in the district of Sumbe, peanuts samples exceeded the MTL-EU (4 µ g/kg) and MTL-Codex (10 µ g/kg) levels by around 30% and 20%, respectively, with the maximum level of AFs being 52.3 µ g/kg (Table 2; Figure 3). The highest levels of contamination in the district of Sumbe may result from the samples having been collected from local markets, without knowledge of the time and conditions of storage of the products. For the remaining districts, samples were collected from the producers, either from a field or storage house. Beans and cassava flour were the least contaminated products in Toxins 2024,16, 516 7 of 16 the province in terms of AF incidence and concentration. None of the samples reached the MTLs. Toxins 2024, 16, x FOR PEER REVIEW 7 of 17 Figure 3. Boxplots of the average total aflatoxin concentrations (1 + log10 µg/kg) in Angola for corn (five districts, Kruskal–Wallis test, followed by Dunn’s multiple comparison) and peanuts (two districts, Mann–Whitney U test). The bars represent the minimum and maximum intervals; different letters highlight significant differences (p < 0.05) between the districts for corn and peanuts. 2.2. Incidence of Total Aflatoxins in Mozambique In Mozambique, AFTs were detected in all the matrices studied. Corn and rice had the highest incidences (Table 1; Figure 1)—100% and 70%, respectively. Corn showed significantly higher contamination than the other crops analyzed (Figure 4). Cassava showed the lowest incidence and AFT levels, and no samples exceeded the MTLs (Table 2). Figure 4. Boxplot of the average total aflatoxin concentrations (1 + log10 µg/kg) in various staple foods from Mozambique. The bars represent the minimum and maximum intervals; different letters highlight significant differences (p < 0.05) between the matrices after analysis via Kruskal–Wallis test, followed by Dunn’s multiple comparison. log Aflatoxin (μg/kg) Figure 3. Boxplots of the average total aflatoxin concentrations (1 + log10 µ g/kg) in Angola for corn (five districts, Kruskal–Wallis test, followed by Dunn’s multiple comparison) and peanuts (two districts, Mann–Whitney U test). The bars represent the minimum and maximum intervals; different letters highlight significant differences (p< 0.05) between the districts for corn and peanuts. 2.2. Incidence of Total Aflatoxins in Mozambique In Mozambique, AFTs were detected in all the matrices studied. Corn and rice had the highest incidences (Table 1; Figure 1)—100% and 70%, respectively. Corn showed significantly higher contamination than the other crops analyzed (Figure 4). Cassava showed the lowest incidence and AFT levels, and no samples exceeded the MTLs (Table 2). Toxins 2024, 16, x FOR PEER REVIEW 7 of 17 Figure 3. Boxplots of the average total aflatoxin concentrations (1 + log10 µg/kg) in Angola for corn (five districts, Kruskal–Wallis test, followed by Dunn’s multiple comparison) and peanuts (two districts, Mann–Whitney U test). The bars represent the minimum and maximum intervals; different letters highlight significant differences (p < 0.05) between the districts for corn and peanuts. 2.2. Incidence of Total Aflatoxins in Mozambique In Mozambique, AFTs were detected in all the matrices studied. Corn and rice had the highest incidences (Table 1; Figure 1)—100% and 70%, respectively. Corn showed significantly higher contamination than the other crops analyzed (Figure 4). Cassava showed the lowest incidence and AFT levels, and no samples exceeded the MTLs (Table 2). Figure 4. Boxplot of the average total aflatoxin concentrations (1 + log10 µg/kg) in various staple foods from Mozambique. The bars represent the minimum and maximum intervals; different letters highlight significant differences (p < 0.05) between the matrices after analysis via Kruskal–Wallis test, followed by Dunn’s multiple comparison. log Aflatoxin (μg/kg) Figure 4. Boxplot of the average total aflatoxin concentrations (1 + log10 µ g/kg) in various staple foods from Mozambique. The bars represent the minimum and maximum intervals; different letters highlight significant differences (p< 0.05) between the matrices after analysis via Kruskal–Wallis test, followed by Dunn’s multiple comparison. Toxins 2024,16, 516 8 of 16 In Mozambique, rice and corn were only collected in Gaza Province since these crops are not significant in the province of Inhambane. On the other hand, cassava flour was only sampled from Inhambane. Among the sampled products, only peanuts were collected from both provinces. The incidence of Afs in corn produced in Mozambique reached 100% in the three districts of Gaza province (Table 2). Because of the high variance, the differences between districts were not statistically significant (p> 0.05), but Chokwe district showed the highest average (1972.6 µ g/kg) and median (66.5 µ g/kg), with two samples reaching AFT contamination levels as high as 9200 µg/kg (Table 2; Figure 5). Toxins 2024, 16, x FOR PEER REVIEW 8 of 17 In Mozambique, rice and corn were only collected in Gaza Province since these crops are not significant in the province of Inhambane. On the other hand, cassava flour was only sampled from Inhambane. Among the sampled products, only peanuts were collected from both provinces. The incidence of Afs in corn produced in Mozambique reached 100% in the three districts of Gaza province (Table 2). Because of the high variance, the differences between districts were not statistically significant (p > 0.05), but Chokwe district showed the highest average (1972.6 µg/kg) and median (66.5 µg/kg), with two samples reaching AFT contamination levels as high as 9200 µg/kg (Table 2; Figure 5). Figure 5. Average total aflatoxin concentrations (µg/kg) in various staple foods of Mozambique in the six districts (top: province of Gaza; bottom: province of Inhambane). Error bars represent the minimum and maximum intervals. Different letters highlight statistical differences (p < 0.05) between districts (determined via Kruskal–Wallis test, followed by Dunn’s multiple comparison, for all matrices except for peanuts in Gaza, where the Mann–Whitney U test was applied). In the districts of Chokwe and Manjacaze, more than 80% of the corn samples exceeded the MTL-EU (4 µg/kg) and MTL-Codex (15 µg/kg) levels (Table 2). Concerning rice, the highest incidence was observed in the district of Manjacaze, Gaza Province, with a positive rate of 90% and 60% exceeding the MTL. Manjacaze samples were significantly (p < 0.05) more contaminated than those from Chongoene and Chokwe (Figure 5). Peanuts had the highest incidence (50%) and median (2.2 µg/kg) in the district of Massinga, Inhambane Province, with the highest absolute level being 496 µg/kg (Table 2). Nonetheless, there were no significant differences between districts. Cassava flour (locally named rali) was the least contaminated product sampled in the country. It had the highest incidence in the district of Massinga, Inhambane Province, with a positive rate of around Chókwe Chongoene Manjacaze log Aflatoxin (μg/kg) Chókwe Chongoene Manjacaze log Aflatoxin (μg/kg) Inharrime Jangamo Massinga log Aflatoxin (μg/kg) Figure 5. Average total aflatoxin concentrations ( µ g/kg) in various staple foods of Mozambique in the six districts (top: province of Gaza; bottom: province of Inhambane). Error bars represent the minimum and maximum intervals. Different letters highlight statistical differences (p< 0.05) between districts (determined via Kruskal–Wallis test, followed by Dunn’s multiple comparison, for all matrices except for peanuts in Gaza, where the Mann–Whitney U test was applied). In the districts of Chokwe and Manjacaze, more than 80% of the corn samples exceeded the MTL-EU (4 µ g/kg) and MTL-Codex (15 µ g/kg) levels (Table 2). Concerning rice, the highest incidence was observed in the district of Manjacaze, Gaza Province, with a positive rate of 90% and 60% exceeding the MTL. Manjacaze samples were significantly (p< 0.05) more contaminated than those from Chongoene and Chokwe (Figure 5). Peanuts had the highest incidence (50%) and median (2.2 µ g/kg) in the district of Massinga, Inhambane Province, with the highest absolute level being 496 µ g/kg (Table 2). Nonetheless, there were no significant differences between districts. Cassava flour (locally named rali) was the least contaminated product sampled in the country. It had the highest incidence in the district of Massinga, Inhambane Province, with a positive rate of around 70% but only one sample Toxins 2024,16, 516 9 of 16 exceeding the MTLs (Table 2). The level of contamination in cassava flour from Massinga was statistically higher (p< 0.05) than that from Jangamo and Inharrime (Figure 5). 2.3. Comparison of Crops Between Angola and Mozambique All crops sampled from both countries—corn, peanuts, and cassava—showed higher contamination in Mozambique than in Angola (p< 0.0071). Corn and cassava from Mozambique stood out in terms of contamination compared to Angola (p< 0.001 and p= 0.028, respectively), while for peanuts, there were no significant differences (p= 0.677) (Figure 6). For corn, it is noticeable that the risk was much higher in Mozambique. Toxins 2024, 16, x FOR PEER REVIEW 9 of 17 70% but only one sample exceeding the MTLs (Table 2). The level of contamination in cassava flour from Massinga was statistically higher (p < 0.05) than that from Jangamo and Inharrime (Figure 5). 2.3. Comparison of Crops Between Angola and Mozambique All crops sampled from both countries—corn, peanuts, and cassava—showed higher contamination in Mozambique than in Angola (p < 0.0071). Corn and cassava from Mozambique stood out in terms of contamination compared to Angola (p < 0.001 and p = 0.028, respectively), while for peanuts, there were no significant differences (p = 0.677) (Figure 6). For corn, it is noticeable that the risk was much higher in Mozambique. Figure 6. Comparative analysis of the average total aflatoxin concentrations (1 + log10 µg/kg) in common staple foods from Angola (“staple”_A) and Mozambique (“staple”_M). Error bars represent minimum and maximum values, and different letters highlight statistical differences (p < 0.05) between the same staple for both countries (Mann–Whitney U test). 3. Discussion Due to climate vulnerability, Mozambique is considered one of the countries most affected by AF [25]. However, few studies have analyzed AF contamination in Mozambican food products [7–13]. Furthermore, to the best of our knowledge, this is the first study on AF contamination in food staples produced in Angola. This study found a high level of AFT contamination in corn produced in Mozambique and Angola, with AFT values from Mozambique reaching 9200 µg/kg in two samples and one reaching 8736 µg/kg, while in Angola, the highest detected value was 82.3 µg/kg. Corn is one of the world’s most important food staples, and in both Angola and Mozambique, it is the agricultural product with the highest dietary and economic relevance. Because of its importance and particular susceptibility, corn is also one of the most studied food crops for AF contamination [17]. In general, in the various products analyzed in many African countries, AFB1 contamination levels are relatively high. In a systematic review, Meijer et al. [17] found that among the 27 analyzed studies, 25 indicated a mean AFB1 level in corn of > 5 µg/kg. El-Shanshoury et al. [26] reported a mean AFB1 concentration of 440 µg/kg in corn from Egypt, and individual samples with values as high as 6738 µg/kg (AFB1) (from Nigeria) [27], 9091.8 µg/kg (AFB1) (from Kenya) [28], 3760 µg/kg (AFT) (from Uganda) [29], and up to 2806.5 µg/kg (AFT) (from the log Aflatoxin (μg/kg) a b a b a a Figure 6. Comparative analysis of the average total aflatoxin concentrations (1 + log10 µ g/kg) in common staple foods from Angola (“staple”_A) and Mozambique (“staple”_M). Error bars represent minimum and maximum values, and different letters highlight statistical differences (p< 0.05) between the same staple for both countries (Mann–Whitney U test). 3. Discussion Due to climate vulnerability, Mozambique is considered one of the countries most affected by AF [ 25 ]. However, few studies have analyzed AF contamination in Mozambican food products [ 7 – 13 ]. Furthermore, to the best of our knowledge, this is the first study on AF contamination in food staples produced in Angola. This study found a high level of AFT contamination in corn produced in Mozambique and Angola, with AFT values from Mozambique reaching 9200 µ g/kg in two samples and one reaching 8736 µ g/kg, while in Angola, the highest detected value was 82.3 µ g/kg. Corn is one of the world’s most important food staples, and in both Angola and Mozambique, it is the agricultural product with the highest dietary and economic relevance. Because of its importance and particular susceptibility, corn is also one of the most studied food crops for AF contamination [ 17 ]. In general, in the various products analyzed in many African countries, AFB1 contamination levels are relatively high. In a systematic review, Meijer et al. [ 17 ] found that among the 27 analyzed studies, 25 indicated a mean AFB1 level in corn of > 5 µ g/kg. El-Shanshoury et al. [ 26 ] reported a mean AFB1 concentration of 440 µ g/kg in corn from Egypt, and individual samples with values as high as 6738 µg/kg (AFB1) (from Nigeria) [ 27 ], 9091.8 µ g/kg (AFB1) (from Kenya) [ 28 ], 3760 µ g/kg (AFT) (from Uganda) [ 29 ], and up to 2806.5 µ g/kg (AFT) (from the Democratic Republic of Congo) [ 30 ] have been reported. Few studies have reported low mean AF concentrations. Martinho et al. [ 10 ] investigated 30 samples of corn flour collected at milling factories in Nampula, Toxins 2024,16, 516 16 of 16 36. Boni, S.B.; Beed, F.; Kimanya, M.E.; Koyano, E.; Mponda, O.; Mamiro, D.; Kaoneka, B.; Bandyopadhyay, R.; Korie, S.; Mahuku, G. Aflatoxin contamination in Tanzania: Quantifying the problem in maize and groundnuts from rural households. World Mycotox. J. 2021,14, 553–564. [CrossRef] 37. Kamika, I.; Takoy, L.L. Natural occurrence of Aflatoxin B1 in peanut collected from Kinshasa, Democratic Republic of Congo. Food Cont. 2011,22, 1760–1764. [CrossRef] 38. Meneely, J.P.; Kolawole, O.; Haughey, S.A.; Miller, S.J.; Krska, R.; Elliott, C.T. The challenge of global aflatoxins legislation with a focus on peanuts and peanut products: A systematic review. Expo. Health 2023,15, 467–487. [CrossRef] 39. Adjovi, Y.C.S.; Bailly, S.; Gnonlonfin, B.J.G.; Tadrist, S.; Querin, A.; Sanni, A.; Oswald, I.P.; Puel, O.; Bailly, J.D. Analysis of the contrast between natural occurrence of toxigenic Aspergilli of the Flavi section and aflatoxin B1 in cassava. Food Microbiol. 2014, 38, 151–159. [CrossRef] 40. Ono, L.T.; Taniwaki, M.H. Fungi and mycotoxins in cassava (Manihot esculenta Crantz) and its products. Br. J. Food Technol. 2021, 24, e2020240. [CrossRef] 41. Chiona, M.; Ntawuruhunga, P.; Benesi, I.R.M.; Matumba, L.; Moyo, C.C. Aflatoxins contamination in processed cassava in Malawi and Zambia. Afr. J. Food Agric. Nutr. Dev. 2014,14, 8809–8820. [CrossRef] 42. Gnonlonfin, G.J.B.; Hell, K.; Fandohan, P.; Siame, A.B. Mycoflora and natural occurrence of aflatoxins and fumonisin B1 in cassava and yam chips from Benin, West Africa. Int. J. Food Microbiol. 2008,122, 140–147. [CrossRef] [PubMed] 43. Gnonlonfin, G.J.B.; Adjovi, C.S.Y.; Katerere, D.R.; Shephard, G.S.; Sanni, A.; Brimer, L. Mycoflora and absence of aflatoxin contamination of commercialized cassava chips in Benin, West Africa. Food Cont. 2012,23, 333–337. [CrossRef] 44. Jimoh, K.O.; Kolapo, A.L. Mycoflora and aflatoxin production in market samples of some selected Nigerian foodstuffs. Res. J. Microbiol. 2008,3, 169–174. [CrossRef] 45. Kaaya, A.N.; Eboku, D. Mould and aflatoxin contamination of dried cassava chips in eastern Uganda: Association with traditional processing and storage practices. J. Biol. Sci. 2010,10, 718–729. [CrossRef] 46. Muzanila, Y.C.; Brennan, J.G.; King, R.D. Residual cyanogens, chemical composition and aflatoxins in cassava flour from Tanzanian villages. Food Chem. 2000,70, 45–49. [CrossRef] 47. Ediage, E.N.; Di Mavungu, J.D.; Monbaliu, S.; Van Peteghem, C.; De Saeger, S. A validated multianalyte LC-MS/MS method for quantification of 25 mycotoxins in cassava flour, peanut cake and maize samples. J. Agric. Food Chem. 2011,59, 5173–5180. [CrossRef] 48. Manjula, K.; Hell, K.; Fandohan, P.; Abass, A.; Bandyopadhyay, R. Aflatoxin and fumonisin contamination of cassava products and maize grain from markets in Tanzania and the Republic of Congo. Toxin Rev. 2009,28, 63–69. [CrossRef] 49. Essono, G.; Ayodele, M.; Akoa, A.; Foko, J.; Filtenborg, O.; Olembo, S. Aflatoxin-producing Aspergillus spp. and aflatoxin levels in stored cassava chips as affected by processing practices. Food Cont. 2009,20, 648–654. [CrossRef] 50. Ali, N. Aflatoxins in rice: Worldwide occurrence and public health perspectives. Toxicol. Rep. 2019,6, 1188–1197. [CrossRef] [PubMed] 51. Makun, H.A.; Dutton, M.F.; Njobeh, P.B.; Mwanza, M.; Kabiru, A.Y. Natural multi-occurrence of mycotoxins in rice from Niger State, Nigeria. Mycotox. Res. 2011,27, 97–104. [CrossRef] 52. Makun, H.A.; Ojochenemi, A.D.; Yemi, A.H.R.; Tahir, N.; Okechukwu, O.J.; Saidu, M.A.; Ayobami, O.B. Determination of aflatoxins in sesame, rice, millet and acha from Nigeria using HPLC. Chem. Sci. Trans. 2014,3, 1516–1524. [CrossRef] 53. Makun, H.A.; Anjorin, S.T.; Moronfoye, B.; Adejo, F.O.; Afolabi, O.A.; Fagbayibo, G.; Balogun, B.O.; Surajudeen, A.A. Fungal and aflatoxin contamination of some human food commodities in Nigeria. Afr. J. Food Sci 2010,4, 127–135. 54. Badmos, A.O.; Olonode, S.; Oni, E.O.; Adeleye, T.M. Isolation of mycotoxigenic fungi and quantification of aflatoxins from bean flours sold in Abeokuta Nigeria. Niger. J. Biotechnol. 2021,38, 68–73. [CrossRef] 55. SADC. Documento de Políticas Sobre as Alterações Climáticas da SADC: Avaliação das Opções de Políticas Para os Estados Membros da SADC’. SADC Research and Policy Paper Series 01/2012, 2012. Available online: https://www.sadc.int/sites/ default/files/2021-08/SADC_Policy_Paper_Climate_Change_PT_1.pdf (accessed on 1 May 2024). 56. Richardson, K.; Calow, R.; Mayhew, L.; Jobbins, G.; Daoust, G.; Waterson, A.; Griffith, H.; Fox, C.; Amato, R.; Dyer, E.; et al. Relatório de Risco Climático Para a Região da África Austral; Met Office, ODI, FCDO, 2022. Available online: https://www.metoffice.gov.uk/ binaries/content/assets/metofficegovuk/pdf/business/international/climate-risk-reports/southern-portuguese-report.pdf (accessed on 1 July 2024). 57. Abrar, M.; Anjum, F.M.; Butt, M.S.; Pasha, I.; Randhawa, M.A.; Saeed, F.; Waqas, K. Aflatoxins: Biosynthesis, Occurrence, Toxicity, and Remedies. Crit. Rev. Food Sci. Nutr. 2013,53, 862–874. [CrossRef] 58. Romer. Quick Guide. AgraStrip ® Pro WATEX ® AgraVision™ Pro. Available online: https://www.romerlabs.com/en/romerlabs/ msds/filedownload/file_id/505CE143B13143598CEACCAA8F93CBE3/ (accessed on 20 November 2024). 59. International Programme on Chemical Safety (IPCS). Principles and methods for the risk assessment of chemicals in food. In Environmental Health Criteria 240, 2nd ed.; WHO Press: Berlin, Germany, 2020. 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