Reduce Aflatoxin Contamination Research Articles

Evaluation of aflatoxin content in “Cheka” (traditional beverage in South-Western Ethiopia) and its major ingredient (maize)

BackgroundAflatoxin is a toxic cancerous fungal secondary metabolite produced by Aspergillus species. Consumption of aflatoxin-contaminated cereals and their products can cause several health-related effects including acute and chronic aflatoxicosis. This study aims to evaluate the total aflatoxin content in “Cheka” and its major ingredients using the Immuno-Affinity Column Clean-up technique by sensitive HPLC (High-Performance Liquid Chromatography) with fluorescence detection.MethodsThis study followed a completely randomized experimental design to evaluate the level of aflatoxin in traditionally brewed “Cheka” and its major ingredients (maize) by HPLC from November 2019 to June 2020. Traditionally brewed 6 “Cheka” beverages and 6 maize seed samples were collected randomly from Konso and transported to Bless Agri Food Laboratory in Addis Ababa for laboratory evaluation of aflatoxin in samples. The data were analyzed by SPSS version 25.ResultsIn the present study aflatoxin contamination was detected in all maize and “Cheka” samples. A mean total aflatoxin level of 6.78 ± 8.28 μg/kg and 10.76 ± 4.50 μg/kg were observed in maize and “Cheka” samples respectively. The maize taken from above-ground storage (“Gotera”) and underground storage (pitfall) showed a mean total aflatoxin level of 10.23 ± 10.12 μg/kg and 3.35 ± 5.79 μg/kg respectively. The samples taken from “Cheka” prepared from maize of above-ground storage (“Gotera”) and underground storage (pitfall) showed a mean total aflatoxin level of 11.34 ± 3.06 μg/kg and 10.19 ± 6.35 μg/kg respectively. Aflatoxin G family was not detected in both maize and “Cheka” samples while aflatoxin B1 and B2 contributed to the total aflatoxin level. AFB1 predominantly contributed to the contamination of all samples. Although there was no significant difference while comparing between mean total aflatoxin of any other sample types, a significant difference was observed for the AFB1 mean level of pitfall maize and their respective “Cheka” samples (P = 0.033).ConclusionThe mean level of AFB1 in pitfall maize differs from a respective “Cheka” sample. As most of the samples evaluated for aflatoxin contamination showed levels above healthy cut-off points of aflatoxin set by different authorities like the European Union, CODEX, and Ethiopian Standards Agency, there must be a protracted interventional approach to reduce aflatoxin contamination in maize and its products in the region.

Assessment the Level of Awareness of Aflatoxin Contaminations in Maize-Based Meals Among Boarding School Personnel

Tanzania is a tropical country that lies few degrees south of the equator The coast area includes regions such as Dar es Salaam and Coastal region which are hot and humid with cooling breezes of the Indian Ocean. Awareness of society is a crucial aspect of ensuring the safety and quality of food. One of the risk factors in food safety is the presence of aflatoxin in various foods such as cereals, and groundnuts. The aim of this study was to assess the levels of awareness of aflatoxin B1 contamination in maize and maize flour used for meals in boarding secondary schools. A total of 90 respondents from 30 schools from 7 districts of the two regions were interviewed. Semi-structured questionnaires were used to collect information and the survey showed that 74.4% of the respondents were aware of aflatoxin contamination. 85.6% of respondents know that aflatoxin is found in food and only 14.4% were not aware. 74.4% were capable of selecting the correct list of food that can be contaminated with aflatoxin while 11.1% selected the wrong list. 14.4% of the respondents were unable to select the list of foods that can be contaminated with aflatoxin. These results indicate that most of them are aware of the issue of aflatoxin contamination in maize and its products which is good for reducing aflatoxin contamination in food products and its effect. An effective and broad awareness program for the society including boarding school personnel and students on good management of food for prevention of aflatoxins contamination and its health effects is necessary, as maize and its products are the most consumed grain in the study area.

Aflatoxin Decontamination in Maize Steep Liquor Obtained from Bioethanol Production Using Laccases from Species within the Basidiomycota Phylum.

Maize (Zea mays L.) is an important crop in Argentina. Aspergillus section Flavi can infect this crop at the pre-harvest stage, and the harvested grains can be contaminated with aflatoxins (AFs). During the production of bioethanol from maize, AF levels can increase up to three times in the final co-products, known as, dry and wet distiller's grain with solubles (DDGS and WDGS), intended for animal feed. Fungal enzymes like laccases can be a useful tool for reducing AF contamination in the co-products obtained from this process. The aim of the present study was to evaluate the ability of laccase enzymes included in enzymatic extracts (EE) produced by different species in the Basidiomycota phylum to reduce AF (AFB1 and AFB2) accumulation under the conditions of in vitro assays. Four laccase activities (5, 10, 15, and 20 U/mL) exerted by nine isolates were evaluated in the absence and presence of vanillic acid (VA), serving as a laccase redox mediator for the degradation of total AFs. The enzymatic stability in maize steep liquor (MSL) was confirmed after a 60 h incubation period. The most effective EE in terms of reducing AF content in the buffer was selected for an additional assay carried out under the same conditions using maize steep liquor obtained after the saccharification stage during the bioethanol production process. The highest degradation percentages were observed at 20 U/mL of laccase enzymatic activity and 1 mM of VA, corresponding to 26% for AFB1 and 26.6% for AFB2. The present study provides valuable data for the development of an efficient tool based on fungal laccases for preventing AF accumulation in the co-products of bioethanol produced from maize used for animal feed.

Genomic Selection as an Approach to Select for Reduced Aflatoxin Contamination in Peanut Under Terminal Drought Stress

Pre-harvest aflatoxin contamination (PAC) occurs when the peanut is exposed to severe drought and heat stress prior to harvest. Development of genotypes that are either resistant or limiting to Aspergillus infection and/or that can curtail aflatoxin production is a key objective in peanut breeding. Using SNP markers and phenotype data on aflatoxin resistance collected in previous years, we utilized genomic selection (GS) to study PAC resistance in peanut. The technique was validated in the Florida-07 x GP-NC WS 16 recombinant inbred population by assessing high heritability traits. GS was then deployed to study PAC resistance in the Tifrunner x C76-16 and Florida-07 x C76-16 populations. The resultant models yielded prediction accuracy values of 0.24 and 0.23 which while low, were comparable to the heritability values of 0.31 and 0.1 for each population, respectively. Using genomic estimated breeding values (GEBVs), entries were selected for two drought shelter studies. Manual scoring and multispectral imaging were used to acquire end season drought stress data. Low correlation values (-0.15 for shelter A and 0.32 for shelter B) were observed between the GEBVs and actual end season aflatoxin content. Correlations between visual drought ratings and PAC were also low (0.23 and 0.16 for shelter A and B respectively). While strong inverse correlations were observed between GNDVI and visual drought ratings (-0.74 and -0.73 for shelters A and B respectively), GNDVI did not confer a clear advantage for selection of PAC resistance. Ideally, the use of genome-spanning markers in GS may enable selection for a difficult to phenotype trait like PAC resistance. Although this study did not show clear advantages of the method over conventional selection, it is an important step for implementation of GS and the use of GEBVs for trait selection in peanut.

Evaluation of the Level of Aflatoxins in Raw Peanuts and Reduction Levels of Aflatoxins in Peanuts through Nixtamalization (Lime Treatment) and Calcium Enrichment

Nixtamalization has been widely used as a method of reducing aflatoxin contamination in peanuts as well as in calcium enrichment. The aim of this study is to investigate the effects of nixtamalization on aflatoxin and nutrient content in peanuts among wholesalers and retailers at Nyamakima Market in Nairobi, Kenya. A representative sample was drawn from a population of 70 market vendors using a systematic random sampling technique, resulting in 35 raw peanut samples for analysis via ELISA to determine initial aflatoxin levels. These samples were then subjected to nixtamalization treatments of 4, 8, and 16 minutes. The findings revealed that the average concentration of total aflatoxins in peanuts initially exceeded the accepted safety limit, with 71% of the samples failing to meet the standards. However, nixtamalization led to a substantial reduction in aflatoxin levels by 49%, 48%, and 50% after treatment durations of 4, 8, and 16 minutes, respectively. Statistical analysis, including ANOVA and Two-sample T-tests, confirmed significant distinctions between initial and final mean aflatoxin levels post-treatment, as well as variations between treatments. The study also observed a significant variation in calcium levels between the different time treatments, supported by linear regression analysis, which demonstrated a robust correlation between time treatments and calcium levels (R2=0.83, P=0.011). Furthermore, the analysis revealed significant differences in mean moisture contents across various treatments (P=0.000), and a linear relationship between mean moisture content and exposure time (P=0.02). The results emphasize the positive impact of nixtamalization in reducing aflatoxin levels and enhancing calcium content in peanuts. However, it is crucial to note the negative effect on moisture content, which exceeded stipulated limits, potentially raising concerns about product safety and quality.

Reduction of Aflatoxin contamination in coconut oil using concentrated solar radiation

Global demand for edible coconut oil has a rapid growth due to its health benefits. However, the susceptibility to carcinogenic mold contamination, aflatoxin, poses a significant global health concern. Concentrated solar radiation was used in this study as a new initiative to investigate the more efficient elimination of aflatoxin in coconut oil. Samples were collected from the Colombo district, Sri Lanka, as branded (n = 3) and unbranded (n = 5). The initial aflatoxin content was determined using High-Performance Liquid Chromatography (HPLC-FLD) system with AflaStarTM FIT immunoaffinity columns. They were exposed to concentrated solar radiation for 10 (T-1), 20 (T-2), and 30 (T-3) minutes respectively, using a parabolic proto-type solar concentrator. The remaining aflatoxin content was re-determined after each treatment. Following each treatment (T-1, T-2 and T-3), the maximum allowed total Aflatoxin and Aflatoxin B1 (AFB1) content of all coconut oil samples were lower than the set European Union (EU) limits (4.2 µg/kg) with a mean total Aflatoxin reduction of 94.00 ± 6.48 %, 98.67 ± 2.80 %, 100.00 ± 0.00 % respectively. T-1 and T-2 treatments at mean concentrated solar radiation levels (W/m2) of 971 ± 29 and 945 ± 65.4 were recognized as the most efficient at removing total and AFB1 aflatoxin tainted in coconut oil at higher levels.

Evidence of the effect of pre and postharvest practices on aflatoxin contamination in the Forest and Savannah ecozones of Ghana

Food contamination by aflatoxins is a global concern due to their adverse effects on food security, trade, and health. This study contributes to the evidence on the connection between pre and postharvest practices of maize farmers and the levels of aflatoxin contamination, based on a survey of 400 farmers across Forest and Savannah zones in Ghana. The survey involving a semi-structured questionnaire was conducted between September 2019 and March 2020. Information on preharvest practices such as weed control, fertilizer application, and irrigation; and postharvest practices such as drying, shelling, storage, and pest control among others were explored by the questionnaire. A multistage sampling process was employed to determine the sample size of four hundred respondents. One kg of maize was randomly sampled from the farmers for aflatoxin analysis. The results showed that the least aflatoxin type found in the maize sample was Aflatoxin G2 (0.207 μg/kg), while the highest was Afltoxin B1 (9.618 μg/kg). The Savannah zone recorded a lower contamination level of 11.63 μg/kg than the Forest zone of 23.53 μg/kg. Aflatoxin G1 and Aflatoxin G2 were less prevalent among the samples than Aflatoxins B1 and B2. The contamination levels in both zones exceeded the maximum limits, set by Codex, and EU at 10 μg/kg, and 4 μg/kg respectively. Only the Savannah zone contamination level met the maximum limit of contamination of Ghana which is set at 15 μg/kg. About 73% of farmers who demonstrated awareness of aflatoxin contamination had their produce within the maximum limit of Ghana, CODEX, and the EU. Preharvest practices such as fertilizer application, hoeing, and chemical weed control lowered aflatoxin contamination in both zones. The results showed that awareness creation and adoption of pre and postharvest interventions are vital in reducing aflatoxin contamination in the two ecozones.

Effectiveness of complementary sorting methods in reducing aflatoxin contamination in groundnuts

Abstract Aflatoxin contamination of staple foods remains a public health concern in many tropical and sub-tropical countries. In sub-Saharan Africa, groundnuts are a significant source of aflatoxin (AF) in vulnerable populations such as infants and young children. However, there are limited scalable and affordable technological interventions to reduce the risk of aflatoxin ingestion in low and middle-income contexts. This study compared the effectiveness of complementary sorting methods in reducing AF contamination, time taken, and percentage loss of groundnuts. The study also evaluated bulk density and kernel weight as proxies for AF. Groundnuts were sampled from 19 bags at a medium-scale enterprise in Tanzania (Halisi) that processes cereal-based blended flours for complementary feeding. The samples were subjected to six sorting methods: (1) size (S) sorting, which yielded large and small fractions (n = 38); (2) density (D) sorting, which yielded heavy and light fractions (n = 38), (3) visual (V) sorting, (4) the combination of size and visual (SV), (5) the combination of density and visual (DV), and (6) the combination of size, density, and visual (SDV) which yielded grades 1, 2, 3, and 4 (n = 76). Samples of unsorted groundnuts and grades from all six sorting regimes (n = 418) were analysed for total aflatoxin by enzyme-linked immunosorbent assay. Analysis of variance (ANOVA) at a 5% significance level was used to compare AF reduction efficiency. Aflatoxin levels were reduced by 99% for the highest grade (G1) by the SDV sorting method. The SDV sorting method was the most effective in reducing AF contamination by removing 14% outsort (Grade 4) from 1 kg groundnut within 22 min. Bulk density and 100 kernels weight were inversely associated with AF, indicating their value as AF proxies. Scaling up such low-cost sorting methods can significantly reduce AF along the value chain and improve food safety.

Yeast suppresses Aspergillus parasiticus growth and aflatoxins synthesis: Finding a new fungal antagonistic strain based on stored marinade

Aspergillus parasiticus is prone to producing toxic and carcinogenic aflatoxins (AFs) and posing risks to food safety. This study aims to explore the effect of yeasts isolated from marinade on the growth of A. parasiticus and to evaluate the inhibitory effects of these yeasts on the biosynthesis of AFs and their ability to remove AFs. Six yeast strains were screened through 18S rDNA and ITS rDNA gene sequence analysis, and among them, Candida tropicalis, Pichia kudriavzevii, Trichosporon asahii, Lodderomyces elongisporus and Pichia fermentans showed vigorous growth activity in the stored marinade. P. fermentans and L. elongisporus culture solutions significantly inhibited the growth and mycelial differentiation of A. parasiticus and effectively removed AFB1. The volatile compounds of P. fermentans and L. elongisporus significantly inhibited the growth of A. parasiticus, with inhibition rates of 72.10% and 67.03%, respectively. In addition, P. fermentans and L. elongisporus were co-cultured with A. parasiticus in marinade for seven days. The inhibition rates of AFB1 synthesis were 69.06% and 61.78%, while the inhibition rates of AFG1 were 65.89% and 60.02%, respectively. Hence, P. fermentans and L. elongisporus can be used as fungal antagonistic strains to help reduce AFs contamination in the marinade and its products.

Physical Methods for Reduction of Aflatoxins Exposure in Groundnuts in Some Low-Income Countries: A Review

Aflatoxin (AF) is a powerful carcinogen primarily produced by some strains of the fungus Aspergillus flavus and Aspergillus parasiticus, which frequently infest nuts and cereal crops. Groundnuts are among the most widely studied substrates of Aspergillus spp., growth and AF contamination. Aflatoxin contamination is a significant public health concern since chronic exposure is linked to causing carcinogenicity, teratogenicity, hepatotoxicity, estrogenicity, neurotoxicity, childhood growth impairment, and immunotoxicity in humans and animals. Acute exposure to AF contamination is associated with fatal aflatoxicosis due to nausea, vomiting, abdominal pain, and convulsions. Good agricultural practices, control of plant diseases, and favourable storage conditions can limit AF contamination yet do not guarantee complete elimination. Looking for an effective technique to reduce AF to an acceptable regulatory limit has been a great subject among researchers. Physical methods like manual visual sorting, screening, density, roasting, dehulling, winnowing, and decortication can reduce AF contamination while maintaining the quality of the kernel and render the kernels harmless to humans and animals compared to AF degradation by chemicals. Therefore, the present review article found that physical removal/visual sorting efficiently lowered the mean AF content commonly used in low-income countries. We briefly enumerated the effectiveness of various common physical methods in reducing post-harvest AF contamination in groundnuts, particularly their percentage AF reduction and outsort/loss, sufficient AF reduction evidence, feasibility, and scalability. We also highlighted the merits and demerits of these methods and essential information that could be helpful for further investigation.

Effects of inoculation of corn silage with Saccharomyces cerevisiae on silage fermentation characteristics, nutrient digestibility, mycoflora and aflatoxin production

In the present study, fresh whole corn plants along with half milk kernels line were treated with live and hydrolysed yeast with different concentrations before ensiling and kept in airtight bags and then into mini silos in order to achieve anaerobic conditions for proper fermentation. The buckets were opened after different time intervals to characterise the material, quick acidification, dry matter recovery, and aerobic stability of silage respectively. Moreover, mycoflora and aflatoxin contamination were also analysed. The overall result reported that the silage quality was improved by the application of live and hydrolysed yeast. The best result was reported by the application of live yeast (T2: 10 g/kg) which significantly improved the fermentative, proximate, and digestibility parameters and reduced the mycoflora and aflatoxin contamination. Our results present promising new options for the use of natural compounds that may help to improve silage quality and reduce aflatoxin contamination.

Inhibitory effects of epiphytic Kluyveromyces marxianus from Indian senna (Cassia angustifolia Vahl.) on growth and aflatoxin production of Aspergillus flavus

Aspergillus flavus infection and subsequent aflatoxin contamination are considered the major constraints in senna (Cassia angustifolia Vahl.) export. Using native epiphytic yeast to control phytopathogens is a successful strategy for managing plant diseases. In the present investigation, we exploited the antagonistic potential of epiphytic yeast isolates obtained from senna against A. flavus growth and aflatoxin B1 (AFB1) production. Four Kluyveromyces marxianus strains (YSL3, YSL16, YSP12, and YSF9) exhibited vigorous antagonistic activity with a maximum inhibition of 64 %. In vivo evaluation of senna pods showed that K. marxianus strains effectively reduced A. flavus colonization with a population range of 5.87 to 7.08 log10 CFU/g. In contrast, the untreated senna pods were found to have severe fungal colonization with a population of 7.84 log10 CFU/g. In addition, HPLC analysis showed that aflatoxin B1 in senna pods was drastically reduced upon yeast treatment up to 14 DAI. Furthermore, we demonstrated the antifungal action mechanisms of K. marxianus, such as surface colonizing ability on pods, production of antifungal volatiles (VOCs), siderophores, extracellular lytic enzymes, and cell wall binding ability to AFB1. All four strains of K. marxianus showed rapid colonization on the senna pod, and YSP12 reached the maximum population of 7.18 log10 CFU/pod at 9 days after inoculation (DAI). The exposure of A. flavus to K. marxianus VOCs significantly reduced the growth by up to 99 and 93.2 % at 7 and 14 DAI, respectively. Scanning electron microscopic images demonstrated severe mycelial damage and hyphal deformities of A. flavus. In addition, yeast VOCs can reduce aflatoxin biosynthesis in A. flavus by up to 99 and 93.2 % at 7 and 14 DAI, respectively. Gas chromatography–mass spectrometry analysis confirmed the presence of antimicrobial compounds such as dimethyl trisulfide, ethyl acetate, ethanol, 3-methyl butanal, 2-methyl-1-butanol, and 3-methyl-1-butanol in the volatiles. K. marxianus strains produced siderophores and hydrolytic enzymes such as chitinase and β-1,3-glucanase. A higher AFB1 binding ability was observed in the heat-killed cells (47.5 to 70.65 %) than in the viable cells (43.16 to 60.98 %) of K. marxianus. The current study demonstrated that epiphytic K. marxianus isolated from senna could be a successful biocontrol source to reduce aflatoxin contamination in senna pods.

Maize and groundnut crop production among rural households in Zambia: Implications in the management of aflatoxins

Maize and groundnut are important crops for both commercial and smallholder farming in Zambia, whose production is being threatened by their susceptibility to aflatoxin contamination. Despite this threat, there is limited knowledge of household growers' behaviour and applications related to suitable agricultural management practices, as well as growers’ perception and knowledge of aflatoxins and their effects. This limited knowledge has major implications for acute human health effects such as liver cirrhosis and death, cancer, stunting in children, immune system suppression, impaired food conversion, and reduced livestock productivity and/or increased livestock mortality.This cross-sectional survey of smallholder household growers in Zambia was conducted to identify the gaps in the knowledge and application of aflatoxin-associated agricultural management practices. A sample of 3865 maize- and groundnut-producing smallholder farm households were selected in 27 priority districts implementing the Scaling Up Nutrition (SUN)/First 1000 Most Critical Days Programme (MCDP) Phase II. Among the five pre-harvest management practices for maize and groundnuts – namely, controlling weeds, timely planting, controlling pests, and applying basal and top-dressing fertilisers – few households (8%) reported practising all of them. Among the recommended techniques for harvesting and handling maize and groundnuts, the most common harvest-management practices under maize production were drying (95.2% of households) and sorting at harvest (72%). In contrast, very few households (2%) practised at least three of four maize harvest management practices. Similarly, very few households (10%) practised at least 4 of the 6 groundnut harvest-management measures. Comparatively, post-harvest and storage management practices were more commonly practised, although most households did not practise all six post-harvest and storage management measures.Overall, very few households (1% for maize and 4% for groundnuts) were observed to be practising at least 12 of the 14 recommended management practices, implying that there are considerable gaps in the implementation of aflatoxin-related management practices along all stages of maize and groundnut production, consequently posing a significant threat to health and contributing to malnutrition levels in Zambia.As such, there is a need to develop tailored interventions and trainings for farming households, extension officers, and frontline health workers to prevent and manage aflatoxin contamination at different stages of crop production. Furthermore, the elimination of policy constraints, practical barriers of affordability and consumer awareness, and the value attached to the commercial product of Aflasafe, noted to reduce aflatoxin contamination by 80–100%, are of utmost urgency.

Performance of testers with contrasting provitamin A content to evaluate provitamin A maize for resistance to Aspergillus flavus infection and aflatoxin production.

In sub-Saharan Africa (SSA), millions of people depend on maize as a primary staple. However, maize consumers in SSA may be exposed to malnutrition due to vitamin A deficiency (VAD) and unsafe aflatoxin levels, which can lead to serious economic and public health problems. Provitamin A (PVA) biofortified maize has been developed to alleviate VAD and may have additional benefits such as reduced aflatoxin contamination. In this study, maize inbred testers with contrasting PVA content in grain were used to identify inbred lines with desirable combining ability for breeding to enhance their level of resistance to aflatoxin. Kernels of 120 PVA hybrids generated by crossing 60 PVA inbreds with varying levels of PVA (5.4 to 51.7 µg/g) and two testers (low and high PVA, 14.4 and 25.0 µg/g, respectively) were inoculated with a highly toxigenic strain of Aspergillus flavus. Aflatoxin had a negative genetic correlation with β-carotene (r= -0.29, p < 0.0001) and PVA (r = -0.23, p < 0.0001), indicating that hybrids with high PVA content accumulated less aflatoxin than those with low to medium PVA. Both general combining ability (GCA) and specific combining ability (SCA) effects of lines and testers were significant for aflatoxin accumulation, number of spores, PVA, and other carotenoids, with additive gene actions playing a prominent role in regulating the mode of inheritance (GCA/SCA ratio >0.5). Eight inbreds had combined significant negative GCA effects for aflatoxin accumulation and spore count with significant positive GCA effects for PVA. Five testcrosses had combined significant negative SCA effects for aflatoxin with significant positive SCA effects for PVA. The high PVA tester had significant negative GCA effects for aflatoxin, lutein, β-carotene, and PVA. The study identified lines that can be used as parents to develop superior hybrids with high PVA and reduced aflatoxin accumulation. Overall, the results point out the importance of testers in maize breeding programs to develop materials that can contribute to controlling aflatoxin contamination and reducing VAD.

Targeting the Aspergillus flavus p2c gene through host-induced gene silencing reduces A. flavus infection and aflatoxin contamination in transgenic maize.

Aspergillus flavus is an opportunistic fungal pathogen that infects maize and produces aflatoxins. Using biocontrol or developing resistant cultivars to reduce aflatoxin contamination has only achieved limited success. Here, the A. flavus polygalacturonase gene (p2c) was targeted for suppression through host-induced gene silencing (HIGS) to reduce aflatoxin contamination in maize. An RNAi vector carrying a portion of the p2c gene was constructed and transformed into maize B104. Thirteen out of fifteen independent transformation events were confirmed to contain p2c. The T2 generation kernels containing the p2c transgene had less aflatoxin than those without the transgene in six out of eleven events we examined. Homozygous T3 transgenic kernels from four events produced significantly less aflatoxins (P ≤ 0.02) than the kernels from the null or B104 controls under field inoculation conditions. The F1 kernels from the crosses between six elite inbred lines with P2c5 and P2c13 also supported significantly less aflatoxins (P ≤ 0.02) than those from the crosses with null plants. The reduction in aflatoxin ranged from 93.7% to 30.3%. Transgenic leaf (T0 and T3) and kernel tissues (T4) were also found to have significantly higher levels of p2c gene-specific small RNAs. Further, homozygous transgenic maize kernels had significantly less fungal growth (27~40 fold) than the null control kernels 10 days after fungal inoculation in the field. The calculated suppression of p2c gene expression based on RNAseq data was 57.6% and 83.0% in P2c5 and P2c13 events, respectively. These results indicate clearly that the reduced aflatoxin production in the transgenic kernels is due to RNAi-based suppression of p2c expression, which results in reduced fungal growth and toxin production.

Aflatoxin contamination of maize and groundnut in Burundi: Distribution of contamination, identification of causal agents and potential biocontrol genotypes of Aspergillus flavus.

Aflatoxin contamination of the staples maize and groundnut is a concern for health and economic impacts across sub-Saharan Africa. The current study (i) determined aflatoxin levels in maize and groundnut collected at harvest in Burundi, (ii) characterized populations of Aspergillus section Flavi associated with the two crops, and (iii) assessed aflatoxin-producing potentials among the recovered fungi. A total of 120 groundnut and 380 maize samples were collected at harvest from eight and 16 provinces, respectively. Most of the groundnut (93%) and maize (87%) contained aflatoxin below the European Union threshold, 4 μg/kg. Morphological characterization of the recovered Aspergillus section Flavi fungi revealed that the L-morphotype of A. flavus was the predominant species. Aflatoxin production potentials of the L-morphotype isolates were evaluated in maize fermentations. Some isolates produced over 137,000 μg/kg aflatoxin B1. Thus, despite the relatively low aflatoxin levels at harvest, the association of both crops with highly toxigenic fungi poses significant risk of post-harvest aflatoxin contamination and suggests measures to mitigate aflatoxin contamination in Burundi should be developed. Over 55% of the L-morphotype A. flavus did not produce aflatoxins. These atoxigenic L-morphotype fungi were characterized using molecular markers. Several atoxigenic genotypes were detected across the country and could be used as biocontrol agents. The results from the current study hold promise for developing aflatoxin management strategies centered on biocontrol for use in Burundi to reduce aflatoxin contamination throughout the value chain.

Efficient Inhibition of Aspergillus flavus to Reduce Aflatoxin Contamination on Peanuts over Ag-Loaded Titanium Dioxide.

Peanuts are susceptible to aflatoxins produced by Aspergillus flavus. Exploring green, efficient, and economical ways to inhibit Aspergillus flavus is conducive to controlling aflatoxin contamination from the source. In this study, Ag-loaded titanium dioxide composites showed more than 90% inhibition rate against Aspergillus flavus under visible light irradiation for 15 min. More importantly, this method could also reduce the contaminated level of Aspergillus flavus to prevent aflatoxins production in peanuts, and the concentrations of aflatoxin B1, B2, and G2 were decreased by 96.02 ± 0.19%, 92.50 ± 0.45%, and 89.81 ± 0.52%, respectively. It was found that there are no obvious effects on peanut quality by evaluating the changes in acid value, peroxide value, and the content of fat, protein, polyphenols, and resveratrol after inhibition treatment. The inhibition mechanism was that these reactive species (•O2-, •OH-, h+, and e-) generated from photoreaction destroyed cell structures, then led to the reduced viability of Aspergillus flavus spores. This study provides useful information for constructing a green and efficient inhibition method for Aspergillus flavus on peanuts to control aflatoxin contamination, which is potentially applied in the field of food and agri-food preservation.

Adoption of Post-Harvest Strategies to Minimize Aflatoxin Contamination in Groundnut (Arachis Hypogaea) in Ghana

Aflatoxin, a mycotoxin caused by the mold Aspergillus flavus or parasiticus, can have negative impacts on human health, especially vulnerable populations. Several management practices can minimize risk of contamination of groundnut (Arachis hypogaea L.). A survey was conducted with thirty-six farmers who were involved in research designed to develop strategies to minimize aflatoxin contamination in groundnut in northern Ghana in 2017 and again in 2020. Fewer farmers in 2020 were consuming groundnuts with mold that produces aflatoxin or selling grain suspected of containing aflatoxin in local markets. Farmers increased use of tarpaulins as a drying surface in 2020 compared with 2017. Drying on tarpaulin has been shown to reduce aflatoxin contamination going into storage by minimizing spores on groundnut and enabling farmers to cover their crop when rain occurs after harvest and initial drying of pods. Hermetically-sealed bags limit fluctuations in humidity and can maintain groundnut moisture at optimum levels during storage. Farmers did not adopt hermetically-sealed bags to minimize aflatoxin, most likely because of availability and cost. Results from this longitudinal study provide knowledge on what aspects of aflatoxin mitigation after harvest need to be addressed in future research.

Effectiveness of Collaborative Strategy to Reduce Aflatoxin Contamination in Corn

The number of birds that die from diseases caused by aflatoxins in corn is the motivation for this study. The purpose of this research is to a) measure the success of aflatoxin treatment in the preharvest, post-harvest, and Innovative Reduction of Aflatoxin (IRA) processes, b) measure the effect of pre-harvest (PRE) and post-harvest (POST) handling on standard control maize (SQC) with IRA mediation. The test method used&#x0D; Structural Equation Modeling (SEM) with the Partial Least Square (PLS) approach. Findings show that Innovative Reduction of Aflatoxin (IRA) is able to play a role as a mediation of activities in pre-harvest and post-harvest after continuous improvement is carried out in each of its activities. The originality of the research can be seen from the process of forming a corn aflatoxin control strategy as a practical recommendation for farmers in Indonesia.

Impact of frequency of application on the long-term efficacy of the biocontrol product Aflasafe in reducing aflatoxin contamination in maize.

Aflatoxins, produced by several Aspergillus section Flavi species in various crops, are a significant public health risk and a barrier to trade and development. In sub-Saharan Africa, maize and groundnut are particularly vulnerable to aflatoxin contamination. Aflasafe, a registered aflatoxin biocontrol product, utilizes atoxigenic A. flavus genotypes native to Nigeria to displace aflatoxin producers and mitigate aflatoxin contamination. Aflasafe was evaluated in farmers' fields for 3 years, under various regimens, to quantify carry-over of the biocontrol active ingredient genotypes. Nine maize fields were each treated either continuously for 3 years, the first two successive years, in year 1 and year 3, or once during the first year. For each treated field, a nearby untreated field was monitored. Aflatoxins were quantified in grain at harvest and after simulated poor storage. Biocontrol efficacy and frequencies of the active ingredient genotypes decreased in the absence of annual treatment. Maize treated consecutively for 2 or 3 years had significantly (p < 0.05) less aflatoxin (92% less) in grain at harvest than untreated maize. Maize grain from treated fields subjected to simulated poor storage had significantly less (p < 0.05) aflatoxin than grain from untreated fields, regardless of application regimen. Active ingredients occurred at higher frequencies in soil and grain from treated fields than from untreated fields. The incidence of active ingredients recovered in soil was significantly correlated (r = 0.898; p < 0.001) with the incidence of active ingredients in grain, which in turn was also significantly correlated (r = -0.621, p = 0.02) with aflatoxin concentration. Although there were carry-over effects, caution should be taken when drawing recommendations about discontinuing biocontrol use. Cost-benefit analyses of single season and carry-over influences are needed to optimize use by communities of smallholder farmers in sub-Saharan Africa.