Aflatoxin Contamination In Groundnut Research Articles

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.

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.

Aflatoxin contamination in groundnut and maize food products in Eastern and Northern Uganda

Aflatoxin contamination in groundnut and maize food products in Eastern and Northern Uganda

Multiplexed Host-Induced Gene Silencing of Aspergillus flavus Genes Confers Aflatoxin Resistance in Groundnut.

Aflatoxins are immunosuppressive and carcinogenic secondary metabolites, produced by the filamentous ascomycete Aspergillus flavus, that are hazardous to animal and human health. In this study, we show that multiplexed host-induced gene silencing (HIGS) of Aspergillus flavus genes essential for fungal sporulation and aflatoxin production (nsdC, veA, aflR, and aflM) confers enhanced resistance to Aspergillus infection and aflatoxin contamination in groundnut (<20 ppb). Comparative proteomic analysis of contrasting groundnut genotypes (WT and near-isogenic HIGS lines) supported a better understanding of the molecular processes underlying the induced resistance and identified several groundnut metabolites that might play a significant role in resistance to Aspergillus infection and aflatoxin contamination. Fungal differentiation and pathogenicity proteins, including calmodulin, transcriptional activator-HacA, kynurenine 3-monooxygenase 2, VeA, VelC, and several aflatoxin pathway biosynthetic enzymes, were downregulated in Aspergillus infecting the HIGS lines. Additionally, in the resistant HIGS lines, a number of host resistance proteins associated with fatty acid metabolism were strongly induced, including phosphatidylinositol phosphate kinase, lysophosphatidic acyltransferase-5, palmitoyl-monogalactosyldiacylglycerol Δ-7 desaturase, ceramide kinase-related protein, sphingolipid Δ-8 desaturase, and phospholipase-D. Combined, this knowledge can be used for groundnut pre-breeding and breeding programs to provide a safe and secure food supply.

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.

Microbial and Fungal Contamination of Staple Foods in Port Harcourt, Nigeria: Special Attention to High Aflatoxin Risk

Background: Microbial and fungal contamination of agricultural produce has been a health challenge over the years. The present study surveyed microbial and aflatoxin contamination in groundnut, maize, and cowpea collected from Port Harcourt, Nigeria.&#x0D; Methods: Ninety samples of maize, groundnut, and cowpea were purchased from six major markets in Port Harcourt, Nigeria. The samples were first examined for insect pest infestation, then Moisture Content (MC), microbial, and aflatoxin contamination. Characterization of bacterial isolates was determined based on their morphological and cultural characteristics. Statistical analyses were performed using SPSS 20.0&#x0D; Results: Data showed that 50% of groundnut samples and 33.33% of maize samples had total aflatoxins levels above World Health Organization (WHO) acceptable limits of 0.5-15 µg/kg. MC for groundnut, maize, and cowpea samples significantly ranged from 2.48-5.55%, 9.00-11.25%, and 9.50-12.48%, respectively. The mean bacterial count for groundnut, maize, and cowpea samples ranged from 0.7×108-1.7×108 Colony Forming Unit (CFU)/g, 0.3×108-1.7×108 CFU/g, and 0.7×108-1.9×108 CFU/g, respectively. Bacterial isolates, including Pseudomonas sp., Streptococcus sp., and Clostridium sp. were isolated from groundnut while Bacillus sp., Staphylococcus sp., Proteus sp., and Escherichia coli were isolated from maize and cowpea. Fungal isolates, including Aspergillus flavus and A. niger were isolated from groundnut and maize.&#x0D; Conclusion: This study revealed the health risk exposure of consumers of the assayed staples in Port Harcourt of Nigeria, especially groundnut which had very high aflatoxin levels in most of the markets.

Mitigation of Aflatoxin Contamination in Groundnuts using Trichoderma viride

Groundnuts are often prone to contamination by Microorganisms during pre-harvest or post-harvest storage. One such contaminant is Aspergillus flavus which is abundantly found in soil and air. Several strains of A. flavus are known to produce mycotoxins named as aflatoxins. These aflatoxins are potent carcinogenic agents whose destruction has become a challenging task in the present scenario. Various physical and chemical methods are available to eliminate the growth of Aspergillus flavus but these methods have several demerits. The present study is based on biological control of Aspergillus flavus using Trichoderma viride strain TV 10. Antagonistic studies of Tv 10 against A.flavus were carried out by performing dual culture technique.

Bio-competitive exclusion: efficacy of non-aflatoxigenic Aspergillus section Flavi-L morphotypes in control of aflatoxigenic Aspergillus flavus in groundnuts (Arachis hypogaea L.)

BackgroundThe biological control mechanism of Aspergillus flavus (aflatoxigenic) strains in groundnuts with atoxigenic strains from the same species through competitive exclusion employed the use of endemic and well-adapted strains within the agro-ecological zones of Zimbabwe. The selected elite non-aflatoxigenic isolates of A. flavus native to Zimbabwe were evaluated for their capability to reduce aflatoxin contamination in groundnuts under laboratory conditions.ResultsAverage reduction percentages in aflatoxin B concentration for the 2019 and 2020 set of experiments ranged from 91.6 ± 3.4 to 95.8 ± 3.1% and 90.29 ± 3.6% to 95.29 ± 4.1%, respectively. Levels of aflatoxin in the co-inoculation research experiments administered were significantly reduced in all the experimental units carried out. Treatment efficiencies of the tested isolates in this study at 4:1 and 2:1 ranged from 1.20 to 2.52 and from 1.02 to 1.21, respectively. The efficacy of the tested non-aflatoxigenic strains against the aflatoxigenic strain native to Zimbabwe (ZMW 0127) indicates that the non-aflatoxigenic isolates of A. flavus. have sound practical applications against vast communities of aflatoxin-producing fungi across all the agro-ecological zones in Zimbabwe.ConclusionThe recognized non-aflatoxigenic isolates will be of an incentive as dynamic active ingredients in biocontrol formulations for the decrease in aflatoxins in groundnuts grown in Zimbabwe.

Global Transcriptome Profiling Identified Transcription Factors, Biological Process, and Associated Pathways for Pre-Harvest Aflatoxin Contamination in Groundnut.

Pre-harvest aflatoxin contamination (PAC) in groundnut is a serious quality concern globally, and drought stress before harvest further exacerbate its intensity, leading to the deterioration of produce quality. Understanding the host–pathogen interaction and identifying the candidate genes responsible for resistance to PAC will provide insights into the defense mechanism of the groundnut. In this context, about 971.63 million reads have been generated from 16 RNA samples under controlled and Aspergillus flavus infected conditions, from one susceptible and seven resistant genotypes. The RNA-seq analysis identified 45,336 genome-wide transcripts under control and infected conditions. This study identified 57 transcription factor (TF) families with major contributions from 6570 genes coding for bHLH (719), MYB-related (479), NAC (437), FAR1 family protein (320), and a few other families. In the host (groundnut), defense-related genes such as senescence-associated proteins, resveratrol synthase, seed linoleate, pathogenesis-related proteins, peroxidases, glutathione-S-transferases, chalcone synthase, ABA-responsive gene, and chitinases were found to be differentially expressed among resistant genotypes as compared to susceptible genotypes. This study also indicated the vital role of ABA-responsive ABR17, which co-regulates the genes of ABA responsive elements during drought stress, while providing resistance against A. flavus infection. It belongs to the PR-10 class and is also present in several plant–pathogen interactions.

Aflasafe SN01 is the First Biocontrol Product Approved for Aflatoxin Mitigation in Two Nations, Senegal and The Gambia.

Aflatoxin contamination is caused by Aspergillus flavus and closely related fungi. In The Gambia, aflatoxin contamination of groundnut and maize, two staple and economically important crops, is common. Groundnut and maize consumers are chronically exposed to aflatoxins, sometimes at alarming levels, and this has severe consequences on their health and productivity. Aflatoxin contamination also impedes commercialization in local and international premium markets. In neighboring Senegal, an aflatoxin biocontrol product containing four atoxigenic isolates of A. flavus, Aflasafe SN01, has been registered and is approved for commercial use in groundnut and maize. We detected that the four genotypes composing Aflasafe SN01 are also native to The Gambia. The biocontrol product was tested during two years in 129 maize and groundnut fields and compared with corresponding untreated fields cropped by smallholder farmers in The Gambia. Treated crops contained up to 100% less aflatoxins than untreated crops. A large portion of the crops could have been commercialized in premium markets due to the low aflatoxin content (in many cases no detectable aflatoxins), both at harvest and after storage. Substantial aflatoxin reductions were also achieved when commercially produced groundnut received treatment. Here we report for the first time the use and effectiveness of an aflatoxin biocontrol product registered for use in two nations. With the current scale-out and -up efforts of Aflasafe SN01, a large number of farmers, consumers, and traders in The Gambia and Senegal will obtain health, income, and trade benefits.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Aflatoxin contamination in groundnut (Arachis hypogaea L.); its causes and management

Coming ...

Single Marker Analysis in Groundnut for Tolerance to in vitro Seed Colonization by Aspergillus flavus and Aflatoxin Contamination

Background: Aflatoxin contamination in groundnut is a serious health concern for both humans and ruminants. Genetic resistance is a viable, cost-effective and eco-friendly approach to manage aflatoxin contamination. Molecular markers particularly SSRs have been proved to be very effective in Marker Assisted Selection.Methods: In this study, single marker analysis using 30 SSR markers in 66 groundnut genotypes was executed to know if any selected SSRs were linked to in vitro seed colonization by Aspergillus flavus (IVSCAF) and/or aflatoxin contamination.Result: Single marker analysis revealed significant association of few SSR markers with tolerance to IVSCAF and/or aflatoxin contamination. Four markers viz., GM-1954, GM-1883, pPGPseq-2F05 and S-03 were found to be associated with in vitro seed colonization by A. flavus. The marker GM-1954 has shown a maximum R2 value of 14.07 indicating that 14.07 per cent phenotypic variation for IVSCAF has been explained by this marker (F=0.002**). Further, three markers viz., S-21, S-80 and GM-1954 were found to be associated with tolerance to aflatoxin contamination. It is evident from the results that, the marker GM 1954 has shown association with both IVSCAF as well as aflatoxin contamination. However, the R2 value of GM 1954, which explains the phenotypic variation for aflatoxin contamination, was less (6.21) as compared to that of IVSCAF (14.07).

Using Trichoderma Species in Combination with Cattle Dung as Soil Amendment Improves Yield and Reduces Pre-Harvest Aflatoxin Contamination in Groundnut

Aflatoxin contamination in groundnut constitutes a serious risk to human and animal health. The efficacy of combining five Trichoderma species and cattle dung in the management of aflatoxin-producing Aspergillus flavus under laboratory and field conditions was evaluated. Trichoderma asperellum, T. hamatum, T. viride, T. harzianum and T. pseudokoningii were bioassayed against A. flavus in vitro, while they were applied in combination with cattle dung in the field experiment. A randomized complete block design was used for field treatments with four replications. Trichoderma containing 2.3×108 cfu/gr was applied as seed treatment, while soil application was done using 2.5 kg/ha of sorghum grains as carrier and 5 t/ha cattle dung. Aflatoxin concentration was quantified using high-performance thin-layer chromatography. There was no significant difference among the treatments in the laboratory experiment. However, T. harzianum was the most effective with 72.3% mycelial inhibition of A. flavus. Seed treatment with combination of T. harzianum and cattle dung was most effective in reducing A. flavus soil population to 1.1×103 cfu/gr, while the combination of T. hamatum and cattle dung produced the highest pod yield of 2.7 t/ha, which was significantly higher than carbendazim fungicide. Therefore, integrated approach is recommended in managing aflatoxin contamination in pre-harvest groundnut.

Assessment of fungi incidence, seed germination and aflatoxin contamination of groundnut (Arachis hypogaea L.) from Lagos, Nigeria.

Assessment of fungi incidence, seed germination and aflatoxin contamination of groundnut (Arachis hypogaea L.) from Lagos, Nigeria.

Effect of imposed terminal drought on yield, yield attributing traits and aflatoxin contamination in groundnut (Arachis hypogea L.)

Sixty six genotypes of groundnut were screened under drought stress conditions. Yield, yield attributes andaflatoxin content were estimated at harvest. Reduction in yield and yield attributing traits, except for number of primary branches and amount of aflatoxin contamination under drought stress as compared to normal moisture condition, was observed.

Functional Biology and Molecular Mechanisms of Host-Pathogen Interactions for Aflatoxin Contamination in Groundnut (Arachis hypogaea L.) and Maize (Zea mays L.).

Aflatoxins are secondary metabolites produced by soilborne saprophytic fungus Aspergillus flavus and closely related species that infect several agricultural commodities including groundnut and maize. The consumption of contaminated commodities adversely affects the health of humans and livestock. Aflatoxin contamination also causes significant economic and financial losses to producers. Research efforts and significant progress have been made in the past three decades to understand the genetic behavior, molecular mechanisms, as well as the detailed biology of host-pathogen interactions. A range of omics approaches have facilitated better understanding of the resistance mechanisms and identified pathways involved during host-pathogen interactions. Most of such studies were however undertaken in groundnut and maize. Current efforts are geared toward harnessing knowledge on host-pathogen interactions and crop resistant factors that control aflatoxin contamination. This study provides a summary of the recent progress made in enhancing the understanding of the functional biology and molecular mechanisms associated with host-pathogen interactions during aflatoxin contamination in groundnut and maize.

Knowledge, Attitude and Practice of Malawian Farmers on Pre- and Post-Harvest Crop Management to Mitigate Aflatoxin Contamination in Groundnut, Maize and Sorghum-Implication for Behavioral Change.

A knowledge, attitude and practice (KAP) study was conducted in three districts of Malawi to test whether the training had resulted in increased knowledge and adoption of recommended pre- and post-harvest crop management practices, and their contribution to reducing aflatoxin contamination in groundnut, maize and sorghum. The study was conducted with 900 farmers at the baseline and 624 farmers at the end-line, while 726 and 696 harvested crop samples were collected for aflatoxin testing at the baseline and end-line, respectively. Results show that the knowledge and practice of pre- and post-harvest crop management for mitigating aflatoxin were inadequate among the farmers at the baseline but somewhat improved after the training as shown at the end-line. As a result, despite unfavorable weather, the mean aflatoxin contamination level in their grain samples decreased from 83.6 to 55.8 ppb (p < 0.001). However, it was also noted that increased knowledge did not significantly change farmers’ attitude toward not consuming grade-outs because of economic incentive incompatibility, leaving potential for improving the practices further. This existing gap in the adoption of aflatoxin mitigation practices calls for approaches that take into account farmers’ needs and incentives to attain sustainable behavioral change.

The Atoxigenic Biocontrol Product Aflasafe SN01 Is a Valuable Tool to Mitigate Aflatoxin Contamination of Both Maize and Groundnut Cultivated in Senegal.

Aflatoxin contamination of groundnut and maize infected by Aspergillus section Flavi fungi is common throughout Senegal. The use of biocontrol products containing atoxigenic Aspergillus flavus strains to reduce crop aflatoxin content has been successful in several regions, but no such products are available in Senegal. The biocontrol product Aflasafe SN01 was developed for use in Senegal. The four active ingredients of Aflasafe SN01 are atoxigenic A. flavus genotypes native to Senegal and distinct from active ingredients used in other biocontrol products. Efficacy tests on groundnut and maize in farmers' fields were carried out in Senegal during the course of 5 years. Active ingredients were monitored with vegetative compatibility analyses. Significant (P < 0.05) displacement of aflatoxin producers occurred in all years, districts, and crops. In addition, crops from Aflasafe SN01-treated fields contained significantly (P < 0.05) fewer aflatoxins both at harvest and after storage. Most crops from treated fields contained aflatoxin concentrations permissible in both local and international markets. Results suggest that Aflasafe SN01 is an effective tool for aflatoxin mitigation in groundnut and maize. Large-scale use of Aflasafe SN01 should provide health, trade, and economic benefits for Senegal.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Prevalence of aflatoxin contamination in groundnuts in Pune city

Background: Aflatoxin contamination in groundnuts is caused by the fungi Aspergillus flavus and Aspergillus parasiticus. In this study, the prevalence of aflatoxin B1 in groundnuts has been assessed. Aflatoxins are highly carcinogenic, mutagenic and teratogenic. They are known to cause hepatocellular toxicity. The aim of the study is to estimate prevalence of aflatoxin contamination in groundnuts sold in the city of Pune and to assess the awareness about aflatoxin contamination amongst shopkeepers of selected shops/vendors.Methods: Sampling of groundnuts was conducted in 17 out of 144 administrative wards of Pune city. Hundred samples weighing 250g each were purchased from the randomly selected stores and transported in black polythene bags to The State Public Health Laboratory, Pune. Thin layer chromatography (TLC) was used by the laboratory to determine levels of aflatoxin B1. A pre-structured questionnaire was used for assessment of knowledge of aflatoxin contamination amongst vendors.Results: Out of 100 samples, four samples were contaminated with aflatoxin. However the maximum contamination was 0.6 parts per billion, which is well within the permissible limit of 30 parts per billion. Awareness of aflatoxin contamination amongst vendors was six percent. Ninety four percent of vendors were unaware of the concept of aflatoxin contamination.Conclusions: It is necessary to educate vendors, suppliers and handlers about the health hazards caused by this toxic fungus for the benefit of the average consumer.

Pseudomonas fluorescens Pf7: A Potential Biocontrol Agent against Aspergillus flavus Induced Aflatoxin Contamination in Groundnut

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.