Articles de revues : « Aflatoxin »

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Rosim, Roice Eliana, Carlos Augusto Fernandes de Oliveira et Carlos Humberto Corassin. « Aflatoxina M1 e Aflatoxina B1-lisina como Biomarcadores de Avaliação da Eficiência de Adsorventes para Aflatoxinas : Artigo de Revisão ». Ensaios e Ciência : C. Biológicas, Agrárias e da Saúde 22, n^o 3 (30 décembre 2018) : 171. http://dx.doi.org/10.17921/1415-6938.2018v22n3p171-178.

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A contaminação de alimentos por aflatoxinas, principalmente, a aflatoxina B1 (AFB1) representa um problema mundial para a saúde humana e animal. Uma forma de avaliar a exposição a estes contaminantes é analisando a dieta para verificar a ocorrência destes compostos. Esta metodologia, no entanto, tem limitações devido à variabilidade das aflatoxinas encontradas nos alimentos e às diferenças individuais na toxicocinética dos compostos. Por outro lado, o biomonitoramento de aflatoxinas em fluidos biológicos se utilizando de biomarcadores gera informações mais confiáveis sobre a exposição a estas toxinas nos indivíduos. O uso de adsorventes químicos na ração animal possibilita a detoxificação de aflatoxinas sem produzir efeitos tóxicos nem alterar as propriedades nutricionais. Este trabalho teve por objetivo revisar os dados publicados sobre a eficiência in vitro e in vivo de adsorventes para aflatoxinas, bem como estudos referentes ao uso da aflatoxina M1 (AFM1) e da AFB1-lisina como biomarcadores para avaliar a redução da biodisponibilidade da AFB1 por adsorventes em rações. Trabalhos relevantes publicados nos últimos dez anos (2009-presente) foram selecionados nas bases de dados PubMed, Science Direct e Google Scholar. A determinação de AFM1 no leite e/ou na urina, bem como de AFB1-lisina no soro, indica a biodisponibilidade individual da AFB1 em ensaios para avaliar a eficiência de adsorventes em animais. Deste modo, a utilização destes biomarcadores permite reduzir os custos dos ensaios in vivo, além de proporcionar maior padronização dos experimentos e possibilitar a avaliação da eficiência dos adsorventes em condições de campo. Palavras chave: AFB1. - Adsorventes Minerais. Biomarcadores de Exposição - AFB1-lisina - AFM1 AbstractFood contamination by aflatoxins, mainly aflatoxin B1 (AFB1), is a worldwide concern for human and animal health. A possible way to assess the exposure to these contaminants is through the diet analyses to verify the occurrence of mycotoxins. However, this methodology has important limitations due to the variability of mycotoxins found in the food and the individual differences in the toxicokinetics of the compounds. On the other hand, biomonitoring of aflatoxins in biological fluids using biomarkers generates more reliable information on the exposure to these toxins in individuals. The use of chemical adsorbents in animal feed makes it possible to detoxify mycotoxins without producing toxic effects or altering the nutritional properties. The aim of this study was to revise the available published data on the in vitro and in vivo efficacy of adsorbents for aflatoxins, as well as studies on the use of aflatoxin M1 (AFM1) and AFB1-lysine as biomarkers to evaluate the reduction in the bioavailability of AFB1 by adsorbents in feed. Relevant articles published in the last 10 years (2009-present) were selected in PubMed, Science Direct and Google Scholar. Determination of AFM1 in milk and/or urine, and AFB1-lysine in serum, indicate the individual bioavailability of AFB1 in trials conducted for evaluation of adsorbent’s efficiency in animals. Thus, the use of these biomarkers may reduce the costs of in vivo trials, increase the standardization of experiments, and evaluate the adsorbents’ efficiency under field conditions. Keywords: Aflatoxin B1 – Clays - Exposure Biomarkers - Aflatoxin B1-lysine Aflatoxin M1.

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Surtini, Nentin, Nia Yuliani et Agus Susanto. « PENGIKATAN AFLATOKSIN B1 DENGAN HASIL EKSTRAKSI UMBI ILES-ILES (Amorpophallus oncophylus) SECARA INVITRO ». JURNAL SAINS NATURAL 5, n^o 2 (16 décembre 2019) : 114. http://dx.doi.org/10.31938/jsn.v5i2.262.

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Aflatoksin B1 Binding with Tubers of Iles-Iles (Amorpophallus oncophylus) Extract on InvitroAnimal feed plays an important role in determining livestock productivity and food security for humans. Animal feed produced by the animal feed industry is still corn-soya based, its raw material composition is dominated by soybean and corn meal, which is easily contaminated with aflatoxin. Aflatoxin compounds known to cause disruption to both animals and humans, because it is carcinogenic. Some aflatoxin binding methods have been using glucomannan containing yeast product (GYP), hydrated sodium calcium aluminosilicate (HSCAS), zeolite, bentonite, kaolin, and activated carbon, and this method is imported so the price is quite expensive. This study aims to test the ability of extracted iles-iles as a binder of aflatoxin B1 in feed in vitro. The results showed that iles-iles extract can bind aflatoxin well like glucomannan from Mycosorb although the binding of Aflatoxin by Amorphophalus extract is less bound than the binder of Mycosorb. Giving extracts weighing 41.25; 82.1 and 102.75 mg have the aflatoxin binding ability with a 3.88-axis increase in succession; 6.25 and 5.97 ppb or as high as 9.86; 15.8; 15.2%. The binding of aflatoxin with glucomannan from the mycosorb product was able to absorb 27.10% aflatoxin in 41.25 mg binder weight and decrease in binder material 82.1 mg (19.63%) and 102.75 mg (23.97% ).Keywords: Aflatokin B1, iles-iles tubers, glucomannanABSTRAKPakan ternak memiliki peran penting karena menentukan produktivitas ternak maupun keamanan pangan bagi manusia. Pakan ternak yang diproduksi oleh industri pakan ternak masih berbasis corn-soya, komposisi bahan bakunya didominasi oleh bungkil kedelai dan jagung, yang mudah terkontaminasi aflatoksin. Senyawa aflatoksin diketahui dapat menimbulkan gangguan baik pada hewan maupun manusia, karena bersifat karsinogenik. Beberapa metode pengikatan aflatoksin selama ini menggunakan glucomannan containing yeast product (GYP) (Mycosorb®), hydrated sodium calcium aluminosilicate (HSCAS), Zeolit, bentonit, kaolin, dan karbon aktif dan metode ini bahannya berasal dari import sehingga harganya cukup mahal. Penelitian ini bertujuan untuk menguji kemampuan hasil ekstraksi iles-iles sebagai pengikat aflatoksin B1 dalam pakan secara in vitro. Hasil penelitian didapat bahwa ekstrak iles-iles dapat mengikat aflatoksin dengan baik seperti glukomanan dari Mycosorb walaupun pengikatan Aflatoksin oleh ekstrak Amorphophalus lebih sedikit terikatnya dibandingkan dengan pengikat dari Mycosorb. Pemberian ekstrak dengan berat 41,25 ; 82,1 dan 102,75 mg memiliki kemampuan mengikat aflatoksin dengan kecenderungan meningkat secara berturut turut 3,88; 6,25 dan 5,97 ppb atau sebesar 9,86; 15,8; 15,2%. Pengikatan aflatoksin dengan glukomannan dari produk mycosorb mampu menyerap 27,10% aflatoksin pada penggunaan bahan berat pengikat 41,25 mg dan menurun pada bahan berat bahan pengikat 82,1 mg (19,63%) dan 102,75 mg (23,97%).Kata kunci : Aflatokin B1, umbi iles-iles, glukomanan

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Yabe, Kimiko, Miki Nakamura et Takashi Hamasaki. « Enzymatic Formation of G-Group Aflatoxins and Biosynthetic Relationship between G- and B-Group Aflatoxins ». Applied and Environmental Microbiology 65, n^o 9 (1 septembre 1999) : 3867–72. http://dx.doi.org/10.1128/aem.65.9.3867-3872.1999.

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ABSTRACT We detected biosynthetic activity for aflatoxins G1 and G2 in cell extracts of Aspergillus parasiticusNIAH-26. We found that in the presence of NADPH, aflatoxins G1 and G2 were produced fromO-methylsterigmatocystin and dihydro-O-methylsterigmatocystin, respectively. No G-group aflatoxins were produced from aflatoxin B1, aflatoxin B2, 5-methoxysterigmatocystin, dimethoxysterigmatocystin, or sterigmatin, confirming that B-group aflatoxins are not the precursors of G-group aflatoxins and that G- and B-group aflatoxins are independently produced from the same substrates (O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin). In competition experiments in which the cell-free system was used, formation of aflatoxin G2 from dihydro-O-methylsterigmatocystin was suppressed whenO-methylsterigmatocystin was added to the reaction mixture, whereas aflatoxin G1 was newly formed. This result indicates that the same enzymes can catalyze the formation of aflatoxins G1 and G2. Inhibition of G-group aflatoxin formation by methyrapone, SKF-525A, or imidazole indicated that a cytochrome P-450 monooxygenase may be involved in the formation of G-group aflatoxins. Both the microsome fraction and a cytosol protein with a native mass of 220 kDa were necessary for the formation of G-group aflatoxins. Due to instability of the microsome fraction, G-group aflatoxin formation was less stable than B-group aflatoxin formation. The ordA gene product, which may catalyze the formation of B-group aflatoxins, also may be required for G-group aflatoxin biosynthesis. We concluded that at least three reactions, catalyzed by the ordA gene product, an unstable microsome enzyme, and a 220-kDa cytosol protein, are involved in the enzymatic formation of G-group aflatoxins from eitherO-methylsterigmatocystin or dihydro-O-methylsterigmatocystin.

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Ozer, H., H. I. Oktay Basegmez, T. B. Whitaker, A. B. Slate et F. G. Giesbrecht. « Sampling dried figs for aflatoxin – Part 1 : variability associated with sampling, sample preparation, and analysis ». World Mycotoxin Journal 10, n^o 1 (27 février 2017) : 31–40. http://dx.doi.org/10.3920/wmj2016.2052.

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The variability associated with the aflatoxin test procedure used to estimate aflatoxins in bulk shipments of dried figs was investigated. Sixteen 10 kg laboratory samples were taken from each of twenty commercial bulk lots of dried figs suspected of aflatoxin contamination. Two 55 g test portions were taken from each comminuted laboratory sample using water-slurry comminution methods. Finally, two aliquots from the test portion/solvent blend were analysed for both aflatoxin B1 and total aflatoxins. The total variance associated with testing dried figs for aflatoxins was measured and partitioned into sampling, sample preparation and analytical variance components (total variance is equal to the sum of the sampling variance, sample preparation variance, and analytical variance). Each variance component increased as aflatoxin concentration increased. Using regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation and analytical variances when testing dried figs for aflatoxins. The regression equations were modified to estimate the variances for any sample size, test portion size, and number of analyses for a specific lot aflatoxin concentration. When using the above aflatoxin test procedure to sample a fig lot at 10 μg/kg total aflatoxins, the sampling, sample preparation, analytical, and total variances were 47.20, 0.29, 0.13, and 47.62, respectively. The sampling, sample preparation, and analytical steps accounted for 99.1, 0.6, and 0.3% of the total variance, respectively. For the aflatoxin test procedure used in this study, the sampling step is the largest source of variability.

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Kumar, Vishal, Ashutosh Bahuguna, Srinivasan Ramalingam, Jong Suk Lee, Sung Soo Han, Hyang Sook Chun et Myunghee Kim. « Aflatoxin Reduction and Retardation of Aflatoxin Production by Microorganisms in Doenjang during a One-Year Fermentation ». Journal of Fungi 8, n^o 2 (15 février 2022) : 190. http://dx.doi.org/10.3390/jof8020190.

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Meju, a raw material for doenjang preparation, is highly vulnerable to aflatoxin-producing fungi. The aim of this study was to evaluate the effect of a one-year fermentation on aflatoxins and aflatoxin-producing fungi in doenjang spiked with aflatoxins B1, G1, B2, and G2 and inoculated with toxigenic Aspergillus flavus. A significant reduction in aflatoxins was observed after a year of fermentation, measuring 92.58%, 100%, 98.69%, and 100% of B1, G1, B2, and G2, respectively. After a year of fermentation, 6.95 ± 3.64 µg/kg of total aflatoxin was detected, which represents a 97.88% reduction in the total aflatoxin compared with the initial value (328.83 ± 36.60 µg/kg). Several aflatoxin-degrading fungi (Aspergillus versicolor, Cladosporium subcinereum, Aspergillus ochraceus) and bacteria (Bacillus albus, Bacillus velezensis) isolated from doenjang were identified as the major contributors to the reduction of aflatoxin. Furthermore, it was observed that most of the aflatoxin contamination in doenjang occurred during the meju stage, and this stage was found to be most susceptible to A. flavus contamination and growth. These findings reveal that native microorganisms mediate aflatoxin clean-up in doenjang during fermentation and support the use of such microorganisms as a starter culture for the preparation of aflatoxin-free doenjang.

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Lin, X., X. Hu, Y. Zhang, Y. Xia et M. Zhang. « Bioaccessibility in daily diet and bioavailability in vitro of aflatoxins from maize after cooking ». World Mycotoxin Journal 12, n^o 2 (3 avril 2019) : 173–81. http://dx.doi.org/10.3920/wmj2018.2350.

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Bioavailability is not a constant percentage of a contaminant in food but is affected by many factors, such as food type, treatment, diet structure and interaction with other compounds. To evaluate these influences, we measured the bioaccessibility of aflatoxins from nine naturally polluted maize samples, collected from southeast China, using an in vitro digestion model, and analysed the intestinal transport of aflatoxins by a Caco-2 cell model. Steam cooking treatment could reduce the aflatoxin levels in maize bread. The degradation rates of aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 ranged from 24.9±3.2 to 33.9±3.5%, 27.0±2.0 to 39.0±1.8%, 27.9±7.9 to 34.4±8.2% and 25.6±3.6 to 37.2±6.5%, respectively. As a result, the bioaccessibility of aflatoxins determined by an in vitro digestion model (41.5-63.3%) was much lower than the previously reported 80%. Edible oil could increase the bioaccessibility of aflatoxin, whereas lettuce would decrease the exposure amount from maize. With a Caco-2 cell model, the apparent permeability coefficient exceeding 10-5 cm/s indicated that there is high absorption of aflatoxins in the human body, while the intestinal transport can be effectively restrained in the presence of chlorophyll.

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Olsen, M., P. Johnsson, T. Möller, R. Paladino et M. Lindblad. « Aspergillus nomius, an important aflatoxin producer in Brazil nuts ? » World Mycotoxin Journal 1, n^o 2 (1 mai 2008) : 123–26. http://dx.doi.org/10.3920/wmj2008.1032.

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The relationship between aflatoxin B1 and G1 was examined in samples from 199 aflatoxin contaminated lots of inshell Brazil nuts imported to Europe. In most of the samples, the relationship between B1 and G1 were approximately 50/50 indicating that the major responsible aflatoxin producing fungi cannot be Aspergillus flavus, which produces solely B aflatoxins. Fungal strains were isolated from two batches of Brazil nuts and isolates of both A. nomius and A. flavus could be identified. The A. nomius isolates were good producers of both B and G aflatoxins, while the A. flavus strains only produced B aflatoxins. In conclusion, this study suggests that A. nomius is an important producer of aflatoxins in Brazil nuts and that its occurrence, and possibly other B and G aflatoxin producers, should be further examined since this may influence strategies for prevention and control of aflatoxins in Brazil nuts.

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Leszczyńska, J., J. MasŁowska, A. Owczarek et U. Kucharska. « Determination of aflatoxins in food products by the ELISA method ». Czech Journal of Food Sciences 19, No. 1 (7 février 2013) : 8–12. http://dx.doi.org/10.17221/6567-cjfs.

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To determine the total content of aflatoxins, aflatoxin B1 and aflatoxin M1 in food the ELISA method was used. Milk, dairy products and cereal samples were mainly investigated. A few samples were found to be contaminated with aflatoxins. A great usability of the ELISA method for aflatoxin determination in food was established. Selectivity and sensitivity of the method is reported.

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Varga, J., J. Frisvad et R. Samson. « A reappraisal of fungi producing aflatoxins ». World Mycotoxin Journal 2, n^o 3 (1 août 2009) : 263–77. http://dx.doi.org/10.3920/wmj2008.1094.

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Aflatoxins are decaketide-derived secondary metabolites which are produced by a complex biosynthetic pathway. Aflatoxins are among the economically most important mycotoxins. Aflatoxin B1 exhibits hepatocarcinogenic and hepatotoxic properties, and is frequently referred to as the most potent naturally occurring carcinogen. Acute aflatoxicosis epidemics occur in several parts of Asia and Africa leading to the death of several hundred people. Aflatoxin production has incorrectly been claimed for a long list of Aspergillus species and also for species assigned to other fungal genera. Recent data indicate that aflatoxins are produced by 13 species assigned to three sections of the genus Aspergillus: section Flavi (A. flavus, A. pseudotamarii, A. parasiticus, A. nomius, A. bombycis, A. parvisclerotigenus, A. minisclerotigenes, A. arachidicola), section Nidulantes (Emericella astellata, E. venezuelensis, E. olivicola) and section Ochraceorosei (A. ochraceoroseus, A. rambellii). Several species claimed to produce aflatoxins have been synonymised with other aflatoxin producers, including A. toxicarius (=A. parasiticus), A. flavus var. columnaris (=A. flavus) or A. zhaoqingensis (=A. nomius). Compounds with related structures include sterigmatocystin, an intermediate of aflatoxin biosynthesis produced by several Aspergilli and species assigned to other genera, and dothistromin produced by a range of non-Aspergillus species. In this review, we wish to give an overview of aflatoxin production including the list of species incorrectly identified as aflatoxin producers, and provide short descriptions of the 'true' aflatoxin producing species.

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Stroka, Joerg, Elke Anklam, Urban Jörissen, John Gilbert, Anna Barmark, Carlo Brera, Per-Erik Clasen et al. « Immunoaffinity Column Cleanup with Liquid Chromatography Using Post-Column Bromination for Determination of Aflatoxins in Peanut Butter, Pistachio Paste, Fig Paste, and Paprika Powder : Collaborative Study ». Journal of AOAC INTERNATIONAL 83, n^o 2 (1 mars 2000) : 320–40. http://dx.doi.org/10.1093/jaoac/83.2.320.

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Abstract A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for the determination of aflatoxin B1 and total aflatoxins at European regulatory limits. The test portion is extracted with methanol–water (8 + 2) for dried figs and paprika, and with methanol–water (8 + 2) plus hexane (or cyclohexane) for peanut butter and pistachios. The sample extract is filtered, diluted with phosphate buffer saline, and applied to an immunoaffinity column. The column is washed with water and the aflatoxins are eluted with methanol. Aflatoxins are quantitated by reversed-phase LC with post-column derivatization (PCD) involving bromination. PCD is achieved with either an electrochemical cell (Kobra cell) and addition of bromide to the mobile phase or pyridinium hydrobromide perbromide. Determination is by fluorescence. Peanut butter, pistachio paste, dried fig paste, and paprika powder samples, both naturally contaminated with aflatoxins and containing added aflatoxins, were sent to 16 collaborators in 16 European countries. Test portions of samples were spiked at levels of 2.4 and 9.6 ng/g for total aflatoxins which included 1.0 and 4.0 ng/g aflatoxin B1, respectively. Recoveries for total aflatoxins ranged from 71 to 92% with corresponding recoveries for aflatoxin B1 of 82 to 109%. Based on results for spiked samples (blind duplicates at 2 levels) as well as naturally contaminated samples (blind duplicates at 4 levels, including blank), the relative standard deviation for repeatability ranged from 4.6 to 23.3% for total aflatoxins and from 3.1 to 20.0% for aflatoxin B1. The relative standard deviation for reproducibility ranged from 14.1 to 34.2% for total aflatoxins, and from 9.1 to 32.2% for aflatoxin B1. The method showed acceptable within-laboratory and between-laboratory precision for all 4 matrixes, as evidenced by HORRAT values <1, at the low levels of determination for both total aflatoxins and aflatoxin B1.

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Ayo, E. M., A. Matemu, G. H. Laswai et M. E. Kimanya. « Socioeconomic Characteristics Influencing Level of Awareness of Aflatoxin Contamination of Feeds among Livestock Farmers in Meru District of Tanzania ». Scientifica 2018 (2018) : 1–11. http://dx.doi.org/10.1155/2018/3485967.

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Aflatoxins occurrence in feeds challenges human and animal health. Farmers’ awareness status of these toxins has an effect on their level of exposure. The study assessed the influence of socioeconomic characteristics of farmers on their awareness of aflatoxin contamination of feeds. Data were collected from 258 households and analysed by SPSS program for descriptive statistics and association between socioeconomic characteristics and awareness of aflatoxin contamination of feeds. Over seventy percent of the farmers had never heard about aflatoxins. Education level, specialization, and period of keeping animals had significant influence on aflatoxin awareness. Hearing about aflatoxins was six times higher among farmers who studied life or social sciences than those without specialization and those who studied other fields. Awareness that aflatoxins may occur in feeds was twice higher among farmers with higher education than those with lower education. Perception that aflatoxins in feeds are detoxifiable was threefold higher among young people (with ≤10-year period of keeping animals) than among older ones. Awareness of aflatoxins was particularly low among farmers with low education and those without exposure to life or social sciences and vice versa. Sensitization is recommended to raise farmers’ awareness on aflatoxin contamination of feeds and incorporating aflatoxin knowledge in school curricula.

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Nazhand, Amirhossein, Alessandra Durazzo, Massimo Lucarini, Eliana B. Souto et Antonello Santini. « Characteristics, Occurrence, Detection and Detoxification of Aflatoxins in Foods and Feeds ». Foods 9, n^o 5 (18 mai 2020) : 644. http://dx.doi.org/10.3390/foods9050644.

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Mycotoxin contamination continues to be a food safety concern globally, with the most toxic being aflatoxins. On-farm aflatoxins, during food transit or storage, directly or indirectly result in the contamination of foods, which affects the liver, immune system and reproduction after infiltration into human beings and animals. There are numerous reports on aflatoxins focusing on achieving appropriate methods for quantification, precise detection and control in order to ensure consumer safety. In 2012, the International Agency for Research on Cancer (IARC) classified aflatoxins B1, B2, G1, G2, M1 and M2 as group 1 carcinogenic substances, which are a global human health concern. Consequently, this review article addresses aflatoxin chemical properties and biosynthetic processes; aflatoxin contamination in foods and feeds; health effects in human beings and animals due to aflatoxin exposure, as well as aflatoxin detection and detoxification methods.

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Dahal, Aashma, Ashish Lamichhane et Alina Karna. « Metabolic Pathways and Pathological Outcomes of Aflatoxins : A Review ». Nepal Journal of Health Sciences 1, n^o 2 (31 décembre 2021) : 63–68. http://dx.doi.org/10.3126/njhs.v1i2.42385.

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Aflatoxin is a secondary fungal metabolite that contaminates foods, mostly staple diets like maize, peanuts, chillies, and even rice. These foods are also a major constituent of weaning food for infants in Asia and Sub-Saharan Africa. The fungal metabolite contaminates food during production, harvest, storage, and processing. The contamination is largely promoted by genotypes of crops, soil conditions, temperate regions, and insect activity. Once ingested into the body, aflatoxins get metabolized into different hydroxylated derivatives such as AFb1, AfM1, AFP1, aflatoxicol, and Aflatoxin B1. AFB1 is the most carcinogenic and potent of the known metabolites and they have been categorized as Group I carcinogenic agents by the International Agency for Research on Cancer. The toxic metabolites of aflatoxins have been found in blood samples, breast milk and also have been shown to traverse the placental route. Through various metabolic pathways aflatoxins are responsible for different types of pathological outcomes like gut enteropathy, anemia, stunting, and other immunological disorders. Moreover, socioeconomic determinants have indirectly shown to be strong predictors of aflatoxins exposure and thus its related pathological outcomes. Since we have a very limited number of researches about aflatoxins, this review altogether puts forward what is known about the toxin and its harmful metabolites. Keywords: Aflatoxins; aflatoxinB1; carcinogens; fungal toxins.

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P. Tito, Goodluck, Jovin K. Mugula et Richard Raphael Madege. « A REVIEW OF SELECTED PREHARVEST MANAGEMENT OPTIONS OF ASPERGILLUS FLAVUS AND AFLATOXIN CONTAMINATION OF MAIZE IN TANZANIA ». International Journal of Agriculture, Environment and Bioresearch 07, n^o 05 (2022) : 65–74. http://dx.doi.org/10.35410/ijaeb.2022.5764.

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Maize (Zea mays L.) is a staple food in Tanzania, but it is often susceptible to aflatoxin contamination caused by the Aspergillus flavus fungi. Aflatoxin contamination in crops is influenced by insufficient knowledge of pre-harvest management practices. Due to the toxic nature of aflatoxins, their proportions and concentrations in various food ingredients are subject to strict regulations in developed countries. The contamination resulting from aflatoxins remains one of the critical mycotoxin challenges in Tanzania because it affects food safety, security, trade, and human health. Either, an integrated combination of intervention measures such as biocontrol is the perfect strategy for sustainable reduction of A. flavus and aflatoxin production in maize. This paper explores several agricultural approaches that potentially reduce aflatoxins production in maize. Selected bio-controls such as Trichoderma spp and Atoxigenic A.flavus are among these strategies. The anticipation of this appraisal is to stimulate improvement of the existing aflatoxin management methods and inventions to exploit their effectiveness in managing toxigenic A.flavus and Aflatoxin production at harvest.

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Omara, Timothy, Ambrose K. Kiprop, Phanice Wangila, Alex Paul Wacoo, Sarah Kagoya, Papias Nteziyaremye, Mark Peter Odero, Caroline Kiwanuka Nakiguli et Samuel Baker Obakiro. « The Scourge of Aflatoxins in Kenya : A 60-Year Review (1960 to 2020) ». Journal of Food Quality 2021 (18 février 2021) : 1–31. http://dx.doi.org/10.1155/2021/8899839.

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Aflatoxins are endemic in Kenya. The 2004 outbreak of acute aflatoxicosis in the country was one of the unprecedented epidemics of human aflatoxin poisoning recorded in mycotoxin history. In this study, an elaborate review was performed to synthesize Kenya’s major findings in relation to aflatoxins, their prevalence, detection, quantification, exposure assessment, prevention, and management in various matrices. Data retrieved indicate that the toxins are primarily biosynthesized by Aspergillus flavus and A. parasiticus, with the eastern part of the country reportedly more aflatoxin-prone. Aflatoxins have been reported in maize and maize products (Busaa, chan’gaa, githeri, irio, muthokoi, uji, and ugali), peanuts and its products, rice, cassava, sorghum, millet, yams, beers, dried fish, animal feeds, dairy and herbal products, and sometimes in tandem with other mycotoxins. The highest total aflatoxin concentration of 58,000 μg/kg has been reported in maize. At least 500 acute human illnesses and 200 deaths due to aflatoxins have been reported. The causes and prevalence of aflatoxins have been grossly ascribed to poor agronomic practices, low education levels, and inadequate statutory regulation and sensitization. Low diet diversity has aggravated exposure to aflatoxins in Kenya because maize as a dietetic staple is aflatoxin-prone. Detection and surveillance are only barely adequate, though some exposure assessments have been conducted. There is a need to widen diet diversity as a measure of reducing exposure due to consumption of aflatoxin-contaminated foods.

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Wokorach, Godfrey, Sofie Landschoot, Amerida Lakot, Sidney Arihona Karyeija, Kris Audenaert, Richard Echodu et Geert Haesaert. « Characterization of Ugandan Endemic Aspergillus Species and Identification of Non-Aflatoxigenic Isolates for Potential Biocontrol of Aflatoxins ». Toxins 14, n^o 5 (26 avril 2022) : 304. http://dx.doi.org/10.3390/toxins14050304.

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Acute stunting in children, liver cancer, and death often occur due to human exposure to aflatoxins in food. The severity of aflatoxin contamination depends on the type of Aspergillus fungus infecting the crops. In this study, Aspergillus species were isolated from households’ staple foods and were characterized for different aflatoxin chemotypes. The non-aflatoxigenic chemotypes were evaluated for their ability to reduce aflatoxin levels produced by aflatoxigenic A. flavus strains on maize grains. Aspergillus flavus (63%), A. tamarii (14%), and A. niger (23%) were the main species present. The A. flavus species included isolates that predominantly produced aflatoxins B1 and B2, with most isolates producing a high amount (>20 ug/µL) of aflatoxin B1 (AFB1), and a marginal proportion of them also producing G aflatoxins with a higher level of aflatoxin G1 (AFG1) than AFB1. Some non-aflatoxigenic A. tamarii demonstrated a strong ability to reduce the level of AFB1 by more than 95% when co-inoculated with aflatoxigenic A. flavus. Therefore, field evaluation of both non-aflatoxigenic A. flavus and A. tamarii would be an important step toward developing biocontrol agents for mitigating field contamination of crops with aflatoxins in Uganda.

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Leite, F. M. N., Leite de Souza, J. M. L. de Souza, C. B. da C. Cartaxo, V. de S. Álvares et C. R. da Cunha. « Incidence of Aspergillus flavus, Aspergillus parasiticus and aflatoxins in Brazil nuts in the Amazon forest environment ». World Mycotoxin Journal 7, n^o 2 (1 janvier 2014) : 199–205. http://dx.doi.org/10.3920/wmj2012.1488.

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This work aimed to evaluate, in the Amazon Forest environment, the effect of time on contamination of Brazil nuts with Aspergillus flavus, Aspergillus parasiticus and aflatoxins after falling of the pods. Samples were collected at three different times and analysed for water activity, potentially aflatoxigenic fungi A. flavus and A. parasiticus, other fungi and aflatoxins. The mean values for the parameters tested were: water activity 0.98; A. flavus and A. parasiticus 1.3×101 colony forming units (cfu)/g; other fungi 3.2×103 cfu/g; aflatoxin B1 0.073 μg/kg, aflatoxin B2 0.009 μg/kg, aflatoxin G1 0.034 μg/kg and aflatoxin G2 0.007 μg/kg. The incidence of A. flavus and A. parasiticus was not significantly affected by the time, during which the pods were on the forest soil. Moreover, aflatoxins levels were low during the whole study period, suggesting that adverse forest conditions were not the main factor that stimulate the production of aflatoxins.

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Yan, Chunlei, Qi Wang, Qingli Yang et Wei Wu. « Recent Advances in Aflatoxins Detection Based on Nanomaterials ». Nanomaterials 10, n^o 9 (19 août 2020) : 1626. http://dx.doi.org/10.3390/nano10091626.

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Aflatoxins are the secondary metabolites of Aspergillus flavus and Aspergillus parasiticus and are highly toxic and carcinogenic, teratogenic and mutagenic. Ingestion of crops and food contaminated by aflatoxins causes extremely serious harm to human and animal health. Therefore, there is an urgent need for a selective, sensitive and simple method for the determination of aflatoxins. Due to their high performance and multipurpose characteristics, nanomaterials have been developed and applied to the monitoring of various targets, overcoming the limitations of traditional methods, which include process complexity, time-consuming and laborious methodologies and the need for expensive instruments. At the same time, nanomaterials provide general promise for the detection of aflatoxins with high sensitivity, selectivity and simplicity. This review provides an overview of recent developments in nanomaterials employed for the detection of aflatoxins. The basic aspects of aflatoxin toxicity and the significance of aflatoxin detection are also reviewed. In addition, the development of different biosensors and nanomaterials for aflatoxin detection is introduced. The current capabilities and limitations and future challenges in aflatoxin detection and analysis are also addressed.

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Senyuva, Hamide Z., et John Gilbert. « Immunoaffinity Column Cleanup with Liquid Chromatography Using Post-Column Bromination for Determination of Aflatoxins in Hazelnut Paste : Interlaboratory Study ». Journal of AOAC INTERNATIONAL 88, n^o 2 (1 mars 2005) : 526–35. http://dx.doi.org/10.1093/jaoac/88.2.526.

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Abstract An interlaboratory study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 and total aflatoxins in hazelnut paste at European regulatory limits. The test portion was extracted with methanol–water (6 + 4). The extract was filtered, diluted with phosphate-buffered saline (PBS) solution to a specified solvent concentration, and applied to an immunoaffinity column containing antibodies specific to aflatoxins. The aflatoxins were removed from the immunoaffinity column with methanol, and then quantified by reversed-phase LC with post-column derivatization (PCD) involving bromination. The PCD was achieved with electrochemically generated bromine (Kobra Cell®) followed by fluorescence detection (except for one participant who used pyridinum hydrobromide perbromide for bromination). Hazelnut paste, both naturally contaminated with aflatoxins and blank (<0.1 ng/g) for spiking by participants with aflatoxins, was sent to 14 collaborators in Belgium, The Netherlands, Spain, Turkey, the United Kingdom, and the United States. Test portions were spiked at levels of 4.0 and 10.0 ng/g for total aflatoxins by participants using supplied total aflatoxins standards. Recoveries for total aflatoxins and aflatoxin B1 averaged from 86 to 89%. Based on results for naturally contaminated samples (blind duplicates at 3 levels ranging from 4.0 to 11.8 ng/g total aflatoxins), the relative standard deviation for repeatability (RSDr) ranged from 2.3 to 3.4% for total aflatoxins and from 2.2 to 3.2% for aflatoxin B1. The relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 7.0% for total aflatoxins and from 7.3 to 7.8% for aflatoxin B1. The method showed exceptionally good within-laboratory and between-laboratory precision for hazelnut paste, as evidenced by HORRAT values, which in all cases were significantly below target levels, the low levels of determination for both aflatoxin B1 and total aflatoxins.

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Diprossimo, Vincent P., et Emil G. Malek. « Comparison of Three Methods for Determining Aflatoxins in Melon Seeds ». Journal of AOAC INTERNATIONAL 79, n^o 6 (1 novembre 1996) : 1330–35. http://dx.doi.org/10.1093/jaoac/79.6.1330.

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Abstract The suitability of 3 methods for determining aflatoxins in melon seeds was examined. The first 2 are the Contaminants Branch (CB) method and the Best Foods (BF) method, both official methods for determining aflatoxins in peanuts and peanut products. The third method, the modified CB method–Rapid Modification of the Cottonseed (CB-RCSMod) method, devised in this work, was derived by combining steps from the CB method and the Rapid Modification of the Cottonseed method. The CB method was superior to the other 2 methods for quantitation of aflatoxins. It gave better recoveries and cleaner extracts that exhibit less fluorescent interference for thin-layer chromatography (TLC) than the BF method. Also, its solvent efficiency was better than that of the CB-RCS-Mod method. With the CB method, recoveries from spiked samples were 85.0% for aflatoxin B1 and 90.0% for anatoxin B2. Recoveries of G1 aflatoxins were more variable, averaging 90.0% for aflatoxin d and 72.5% for aflatoxin G2. Total aflatoxin recovery was 86.5% for the CB method. At a low aflatoxin contamination level (8 μg B1/kg sample), aflatoxin B1 was detectable by the CB method but not by the BF method. Detection of aflatoxins in BF method sample extracts by TLC was not improved by the use of chloroform–acetone–water (88 + 12 + 1), benzene–ethanol–water, or ether–methanol–water (96 + 3 +1) in place of the standard chloroform–acetone (88 + 12) developer. Use of ether–methanol–water (96 + 3 + 1) for detecting aflatoxins by TLC in the CB method extracts increased interference compared with the standard chloroform–acetone (88 + 12) developer.

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Almaghrabi, Merfat Abdulrahman. « The Occurrence of Aflatoxins in Date Palm (Phoenix dactylifera L.) Worldwide ». Journal of Food Quality 2022 (7 mars 2022) : 1–9. http://dx.doi.org/10.1155/2022/1326861.

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Due to global warming, the risk of aflatoxins exposure through the consumption of contaminated food has increased. Aflatoxins pose serious health hazards to humans’ and animals’ health because of their carcinogenic, mutagenic, and teratogenic properties and their immunosuppressive effects. Aflatoxin contamination in various agricultural commodities has attracted much attention worldwide. Date palm fruits are among these important commodities that are vulnerable to fungal contamination and consequent aflatoxins production. Furthermore, dates are often consumed directly without any further processing, which may result in direct exposure to aflatoxins. Moreover, dates are the second dried fruits traded worldwide, which reflects the widespread consumption of dates due to their nutritive values in addition to religious and cultural values. Accordingly, this review summarizes and discusses the frequency and incidence of aflatoxin contamination in dates worldwide and outlines the analytical procedure for aflatoxin determination in dates for the first time. The susceptibility of date palm fruits to aflatoxins contamination has been documented at various levels in several regions. The findings urged the importance of conducting more comprehensive studies on aflatoxin occurrence and contamination levels in dates as a likely contributor to the dietary exposure to aflatoxins.

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Jiang, Yun, Ibukun M. Ogunade, Diwakar Vyas et Adegbola T. Adesogan. « Aflatoxin in Dairy Cows : Toxicity, Occurrence in Feedstuffs and Milk and Dietary Mitigation Strategies ». Toxins 13, n^o 4 (17 avril 2021) : 283. http://dx.doi.org/10.3390/toxins13040283.

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Aflatoxins are poisonous carcinogens produced by fungi, mainly Aspergillus flavus and Aspergillus parasiticus. Aflatoxins can contaminate a variety of livestock feeds and cause enormous economic losses, estimated at between US$52.1 and US$1.68 billion annually for the U.S. corn industry alone. In addition, aflatoxin can be transferred from the diet to the milk of cows as aflatoxin M1 (AFM1), posing a significant human health hazard. In dairy cows, sheep and goats, chronic exposure to dietary aflatoxin can reduce milk production, impair reproduction and liver function, compromise immune function, and increase susceptibility to diseases; hence, strategies to lower aflatoxin contamination of feeds and to prevent or reduce the transfer of the toxin to milk are required for safeguarding animal and human health and improving the safety of dairy products and profitability of the dairy industry. This article provides an overview of the toxicity of aflatoxin to ruminant livestock, its occurrence in livestock feeds, and the effectiveness of different strategies for preventing and mitigating aflatoxin contamination of feeds.

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Pickova, Darina, Vladimir Ostry, Jakub Toman et Frantisek Malir. « Aflatoxins : History, Significant Milestones, Recent Data on their Toxicity and Ways to Mitigation ». Toxins 13, n^o 6 (3 juin 2021) : 399. http://dx.doi.org/10.3390/toxins13060399.

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In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey “X” disease in England. The disease was associated with Brazilian groundnut meal affected by Aspergillus flavus. The toxin was named Aspergillus flavus toxin—aflatoxin. From the point of view of agriculture, aflatoxins show the utmost importance. Until now, a total of 20 aflatoxins have been described, with B1, B2, G1, and G2 aflatoxins being the most significant. Contamination by aflatoxins is a global health problem. Aflatoxins pose acutely toxic, teratogenic, immunosuppressive, carcinogenic, and teratogenic effects. Besides food insecurity and human health, aflatoxins affect humanity at different levels, such as social, economical, and political. Great emphasis is placed on aflatoxin mitigation using biocontrol methods. Thus, this review is focused on aflatoxins in terms of historical development, the principal milestones of aflatoxin research, and recent data on their toxicity and different ways of mitigation.

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Petrov, Roman, et Oleksiy Pidlubniy. « Aflatoxicosis of crucians : experimental treatment and biological value of fish ». EUREKA : Life Sciences, n^o 2 (1 avril 2021) : 25–31. http://dx.doi.org/10.21303/2504-5695.2021.001754.

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The aim of this study was to investigate a possibility to decrease a toxic influence of aflatoxin on the fish organism and veterinary-sanitary evaluation of fish, fed by a pure fodder, aflatoxin and ketoconazole+aflatoxin. Fish aflatoxicoses cause essential losses at fish growing using industrial production technologies. It is characterized by decreasing weight gains and increasing kill of commodity fish, worsening fodder conversion. Farmers often use fodders of own production, without conducting laboratory studies, and don’t know about aflatoxins. At the same time because of different reasons, first of all economic ones, they don’t use adsorbents for decreasing the negative influence of aflatoxins on the fish organism. Their use doesn’t guarantee 100 % fish resistance to micotoxicoses and correspondingly product safety for a consumer. Fish, received aflatoxins with food, is dangerous as a food product for humans and animals. Aflatoxins are very stable in the environment, so even thermal processing doesn’t exceed risk of aflatoxin contamination. The article presents a possibility of effective treatment of fish at aflatoxicosis. It is known, that aflatoxin beyond cells is not dangerous. Its activation takes place within a cell by the enzyme system cytochrome Р-450, forming an epoxide, in which result the aflatoxin inclusion complex with DNA forms in the kernel. The veterinary preparation “Ketoconazole” inhibits cytochrome enzymes Р-450, so aflatoxin activation within a cell doesn’t take place, epoxides don’t form, DNA cells are not injured, aflatoxicosis doesn’t develop in fish that has been proved experimentally. The veterinary-sanitary mark of fish, treated for aflatoxicosis, is satisfactory. The importance of this study is in fact that for today there is no developed effective method of fish aflatoxicosis treatment. An influence of aflatoxin on the crucian organism has not been studied experimentally

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Ayeni, Kolawole I., Oluwatosin M. Akinyemi, Tihomir Kovač et Chibundu N. Ezekiel. « Aflatoxin contamination of maize vended in Ondo state, Nigeria, and health risk assessments ». Croatian journal of food science and technology 12, n^o 1 (29 mai 2020) : 123–29. http://dx.doi.org/10.17508/cjfst.2020.12.1.16.

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Aflatoxin contamination of maize is a serious food safety problem worldwide. Despite the widespread consumption of maize in Nigeria, there is limited data on aflatoxin contents of maize vended in open markets in Ondo state, Nigeria. A total of 140 maize samples randomly purchased from major markets in four locations in Ondo state, were screened for total aflatoxins using an ELISA method. Exposure and health risk assessments were performed for the maize consumers by the deterministic and Margin of exposure (MOE) approaches, respectively. About 99% of the maize were contaminated with total aflatoxins (range: 0.65–265 µg/kg; mean: 125.9 µg/kg). Aflatoxin levels exceeding the 4 µg/kg set by the European Union for total aflatoxins were found in 88% of the maize whilst more than one half contained at least 100 µg/kg aflatoxins. The average probable daily intake values were 830, 332 and 138 ng/kg bw/day for the average children, adolescent and adult populations, respectively. Consequently, MOEs for the respective populations were 0.20, 0.51 and 1.23, suggesting a high level of health risk for consumers of maize vended in open markets in Ondo state due to high aflatoxin levels. Maize farmers and households in Ondo state need urgent aflatoxin mitigation interventions.

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Safameher, A. R., A. Allameh et M. Shivazad. « Performance and biochemical parameters of broiler chicks fed aflatoxin-contaminated and ammonia-treated corn ». Proceedings of the British Society of Animal Science 2005 (2005) : 163. http://dx.doi.org/10.1017/s1752756200010747.

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Aflatoxins (AF), natural contaminants of food stuffs and are toxic metabolites produced by Aspergillus flavus and A. parasiticus. Aflatoxins damage the liver, kidney and thymus resulting in a variety of effects including decreased growth rate, poor productivity and immunosuppression. Recently we have reported that ammonia solution can directly inhibit aflatoxin production in Aspergillus parasiticus in culture growth (Namazi et al., 2001). A study was conducted to determine the efficacy ammoniation of contaminated-corn with aflatoxin in decreasing aflatoxin in diet of broiler chicks and its effects on production and biochemical parameters.

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Lien, Keng-Wen, Xin Wang, Min-Hsiung Pan et Min-Pei Ling. « Assessing Aflatoxin Exposure Risk from Peanuts and Peanut Products Imported to Taiwan ». Toxins 11, n^o 2 (1 février 2019) : 80. http://dx.doi.org/10.3390/toxins11020080.

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Aflatoxins are highly toxic and cause disease in livestock and humans. In order to assess Taiwan population exposure to aflatoxin from peanuts and peanut products, a total of 1089 samples of peanut candy, peanut butter, and peanuts etc. were collected in the period from 2011 to 2017 and analyzed using a liquid chromatography/tandem mass spectrometer. The overall mean contamination levels of aflatoxin in peanuts and peanut products were 2.40 μg/kg of aflatoxin B1, 0.41 μg/kg of aflatoxin B2, 0.19 μg/kg of aflatoxin G1, and 0.03 μg/kg of aflatoxin G2. We use margin of exposure (MOE) as a tool to improve food safety management. According to MOE levels of aflatoxins in peanuts and peanut products from China, Indonesia, Thailand, the United States, and the Philippines were above the safe lower limit of 10,000, indicating an absence of public health or safety risk for the majority of the population. However, products from Vietnam were under the MOE safe lower limit, suggesting that regulatory actions must be continued to avoid excessive consumer exposure.

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Cervino, Christian, Dietmar Knopp, Michael Weller et Reinhard Niessner. « Novel Aflatoxin Derivatives and Protein Conjugates ». Molecules 12, n^o 3 (27 mars 2007) : 641–53. http://dx.doi.org/10.3390/12030641.

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Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

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Bursic, Vojislava, Gorica Vukovic, Igor Jajic, Sanja Lazic, Magdalena Kara, Radmilo Colovic et Djuro Vukmirovic. « Analysis of aflatoxins B1 and G1 in maize by quechers ». Zbornik Matice srpske za prirodne nauke, n^o 124 (2013) : 51–57. http://dx.doi.org/10.2298/zmspn1324051b.

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A reliable and easy method has been developed for the determination of aflatoxins B1 and G2 in maize samples. High performance liquid chromatography coupled with FLD (HPLC-FLD) with photochemical derivatization was used. Mycotoxins were extracted from maize using a QuEChERS-based extraction procedure. The optimized analytical conditions were evaluated in terms of recoveries, reproducibility, LOD, LOQ and linearity for aflatoxin B1 and aflatoxin G1 in maize. Extraction, chromatographic and detection conditions were optimized in order to increase sample sensitivity. The linearity was analyzed in the range of 0.4-20 ?g/kg and the correlation coefficients (R2) were higher than 0.99 for aflatoxins B1 and G1. Blank samples were spiked at 1.0, 2.0 and 4.0 ?g/kg, and the average recovery for aflatoxin G1 was 96.96?1.72% and for aflatoxin B1 it was 86.80?1.24%. RSDs were lower than 25% for both mycotoxins. LOD for both aflatoxins was 0.5 ?g/kg and LOQ was 1.0 ?g/kg, respectively.

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Whitaker, Thomas B., Andrew B. Slate, Merle Jacobs, J. Michael Hurley, Julie G. Adams et Francis G. Giesbrecht. « Sampling Almonds for Aflatoxin, Part I : Estimation of Uncertainty Associated with Sampling, Sample Preparation, and Analysis ». Journal of AOAC INTERNATIONAL 89, n^o 4 (1 juillet 2006) : 1027–34. http://dx.doi.org/10.1093/jaoac/89.4.1027.

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Abstract Domestic and international regulatory limits have been established for aflatoxin in almonds and other tree nuts. It is difficult to obtain an accurate and precise estimate of the true aflatoxin concentration in a bulk lot because of the uncertainty associated with the sampling, sample preparation, and analytical steps of the aflatoxin test procedure. To evaluate the performance of aflatoxin sampling plans, the uncertainty associated with sampling lots of shelled almonds for aflatoxin was investigated. Twenty lots of shelled almonds were sampled for aflatoxin contamination. The total variance associated with measuring B1 and total aflatoxins in bulk almond lots was estimated and partitioned into sampling, sample preparation, and analytical variance components. All variances were found to increase with an increase in aflatoxin concentration (both B1 and total). By using regression analysis, mathematical expressions were developed to predict the relationship between each variance component (total, sampling, sample preparation, and analysis variances) and aflatoxin concentration. Variance estimates were the same for B1 and total aflatoxins. The mathematical relationships can be used to estimate each variance for a given sample size, subsample size, and number of analyses other than that measured in the study. When a lot with total aflatoxins at 15 ng/g was tested by using a 10 kg sample, a vertical cutter mixer type of mill, a 100 g subsample, and high-performance liquid chromatography analysis, the sampling, sample preparation, analytical, and total variances (coefficient of variation, CV) were 394.7 (CV, 132.4%), 14.7 (CV, 25.5%), 0.8 (CV, 6.1%), and 410.2 (CV, 135.0%), respectively. The percentages of the total variance associated with sampling, sample preparation, and analytical steps were 96.2, 3.6, and 0.2, respectively.

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Obade, MI, P. Andang’o, C. Obonyo et F. Lusweti. « Exposure of children 4 to 6 months of age to aflatoxin in Kisumu County, Kenya ». African Journal of Food, Agriculture, Nutrition and Development 15, n^o 69 (30 mars 2015) : 9949–63. http://dx.doi.org/10.18697/ajfand.69.14020.

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Contamination of foods by aflatoxins is a global health problem in both developed and developing countries. Exposure to the toxin s is associated with a range of effects on health including stunting in children. Commodities at high risk of aflatoxin contamination include cereals, legumes, milk, fish and meats. Children are more vulnerable to effects of aflatoxin exposure compared to adults. Being genotoxic , levels of aflatoxins in foods should be kept as low as possible, given that there is no known threshold at which they may pose a health risk . This study investigated the potential exposure of young children to aflatoxin contamination in Kisumu County, Kenya. Kisumu County may have the potential for low to high levels of aflatoxin contamination due to prevailing weather conditions as well as reliance on maize, sorghum, cassava and rice as the main staple foods, groundnuts as snack and omena ( Rastrienobola argentea ) and milk as cheap source s of protein. These foods are also used as weaning foods in the County. Samples of omena , rice, groundnuts, cassava, maize, and sorghum were collected from Kibuye wholesale market , Kibuye open air market , Ahero market , Oile market and Mamboleo market in Kisumu County using a combination of cluster and systematic sampling. Processed cow’s milk samples were collected from supermarkets and raw cow’s milk samples from 3 market milk bazaars in the County . Analysis of solid foods was done using HELICA Total Aflatoxin Assay, intended for quantitative detection of aflatoxin B 1 , B 2 , G 1 and G 2 . Milk sampling was done using the European model outlined in the Codex Alimentarius. Aflatoxin M 1 levels in milk were analyzed using HELICA Aflatoxin M 1 Assay. Aflatoxin levels in the foods ranged from 0 to 34.5 ppb aflatoxin B 1 , 0.012 to 0.127 ppb aflatoxin M 1 in processed milk and 0.0002 to 0.013 ppb aflatoxin M 1 in raw milk . All the food products , except cassava, had samples with detectable aflatoxin levels. Daily aflatoxin consumption ranged from 35 ng (4.43/kgBw/day) to as high as 872 ng (110.4 ng/kgBW ). These findings indicate that weaning children in Kisumu County are potentially exposed to levels of aflatoxins above the permissible amounts , given that the food stuffs that were analyzed are the commonly used weaning food items. Its effects on their health should be assessed and efforts taken to reduce potential exposure both from the commonly suspected sources as well as from milk.

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Smajlovic, Ahmed, Mehmed Muminovic, Indira Mujezinovic et Vitormir Cupic. « Investigation of aflatoxin M1 degradation in milk ». Veterinarski glasnik 66, n^o 5-6 (2012) : 387–94. http://dx.doi.org/10.2298/vetgl1206387s.

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Aflatoxin M1 is a highly toxic 4-hydroxylated metabolite of aflatoxins B1 and B2. It is one of the most potent hepatocarcinogens, mutagens, teratogens and immunosuppressors. Feed is often contaminated with aflatoxigenic moulds and aflatoxins with a high possibility of contaminating milk and dairy products with aflatoxin M1. Samples of artificially contaminated milk were exposed to the effects of physical conditions (temperature of -18oC and for microwaves in a microwave oven), time (during the period from 1 to 12 months) and a combination of the above mentioned conditions. Following this, levels of aflatoxin M1 degradation were established by using the ELISA method. An insignificant decrease in concentration of toxin was observed which indicates that a temperature of -18?C does not significantly influence the concentration of aflatoxin M1 in the artificially contaminated milk. At the same time, treatment of milk with microwaves in a microwave oven showed an insignificant influence on the percentage of aflatoxin M1 absorbance.

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KANKAANPÄÄ, PASI, ELINA TUOMOLA, HANI EL-NEZAMI, JORMA AHOKAS et SEPPO J. SALMINEN. « Binding of Aflatoxin B1 Alters the Adhesion Properties of Lactobacillus rhamnosus Strain GG in a Caco-2 Model ». Journal of Food Protection 63, n^o 3 (1 mars 2000) : 412–14. http://dx.doi.org/10.4315/0362-028x-63.3.412.

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Lactic acid bacteria have been previously reported to possess antimycotoxigenic activities both in vitro and in vivo. The objective of this study was to investigate the effect of aflatoxin B1 on adhesion capability of Lactobacillus rhamnosus strain GG using a Caco-2 adhesion model. Removal of aflatoxin B1 by L. rhamnosus strain GG reduced the adhesion capability of this strain from 30% to 5%. It is therefore concluded that aflatoxins may influence the adhesion properties of probiotics able to sequester them, and subsequently these bacteria may reduce the accumulation of aflatoxins in the intestine via increased excretion of an aflatoxin–bacteria complex.

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Miller, Noah, Helena E. Pretorius et Donald W. Trinder. « Determination of Aflatoxins in Vegetable Oils ». Journal of AOAC INTERNATIONAL 68, n^o 1 (1 janvier 1985) : 136–37. http://dx.doi.org/10.1093/jaoac/68.1.136.

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Abstract A simple method is proposed for determination of aflatoxins in vegetable oils. The method was successfully applied to both crude and degummed oils. The oil sample, dissolved in hexane, was applied to a silica column and washed with ether, toluene, and chloroform; aflatoxins were eluted from the column with chloroform-methanol (97 + 3). As quantitated by thin layer chromatography and liquid chromatography, the oils analyzed contained aflatoxin Bx at levels of 5-200 αg/kg. Recoveries of aflatoxin Bi standards added to aflatoxin-free oils were between 89.5 and 93.5%, with coefficients of variation of 6.3- 8.0%.

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Vongbuddhapitak, Amara, Mary W. Trucksess, Kanoporn Atisook, Duangchan Suprasert et William Horwitz. « Laboratory Proficiency Testing of Aflatoxins in Corn and Peanuts—A Cooperative Project between Thailand and the United States ». Journal of AOAC INTERNATIONAL 82, n^o 2 (1 mars 1999) : 259–63. http://dx.doi.org/10.1093/jaoac/82.2.259.

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Abstract The objective of this project was to conduct an aflatoxin proficiency test program in government, academia, and industry laboratories in Thailand. Aflatoxin-free corn and peanuts and corn and peanuts naturally contaminated with aflatoxins diluted to approximately 25 μg/kg were analyzed. Homogeneity of prepared, naturally contaminated test samples was checked on multiple replicates. The test was conducted according to the ISO/IUPAC/AOAC INTERNATIONAL Harmonized Protocol with z scores indicating laboratory performance. The participants used 3 methods: enzyme-linked immunosorbent assay, thin-layer chromatography, and the minicolumn. Of 19 laboratories that reported results for aflatoxins in naturally contaminated corn, 13 (68%) performed satisfactorily, on the basis of the mean obtained by an expert laboratory, a calculated target value for standard deviation, and the z score. Of 21 laboratories that reported results for aflatoxins in naturally contaminated peanuts, 10 (48%) performed satisfactorily. For aflatoxin-free corn, 6 laboratories reported finding aflatoxins at ≥10 ng/g, chiefly by the minicolumn method; for aflatoxin-free peanuts, 1 laboratory reported finding aflatoxins at >10 ng/g. Subsequently, a workshop of lectures and laboratory sessions was conducted to improve performance. A new and simple successive outlier removal procedure applied to the same data removed the same laboratories as did the use of z scores.

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Mupunga, Innocent, Ilse Janse van Rensburg, Nokuthula Luthuli, Ovokeroye A. Abafe, Leshweni J. Shai et David R. Katerere. « Analysis of Aflatoxin Biomarkers in the Hair of Experimental Animals ». Toxins 13, n^o 8 (16 août 2021) : 570. http://dx.doi.org/10.3390/toxins13080570.

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Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg−1bw−1, 50 ugkg−1bw−1, and 100 ugkg−1bw−1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.

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Xu, Y., Y. Y. Gong et M. N. Routledge. « Aflatoxin exposure assessed by aflatoxin albumin adduct biomarker in populations from six African countries ». World Mycotoxin Journal 11, n^o 3 (18 septembre 2018) : 411–19. http://dx.doi.org/10.3920/wmj2017.2284.

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Aflatoxins are a group of carcinogenic mycotoxins that have been implicated to have other adverse health impacts, including child growth impairment and immune function suppression. Aflatoxin B1is the most toxic and most common of the aflatoxins. Contamination of various food crops is common in sub-Saharan Africa, particularly in staple crops such as maize and groundnuts, leading to chronic dietary exposure in many populations. For many years we have used the aflatoxin albumin adduct as a biomarker of aflatoxin exposure, assessed using a competitive inhibition enzyme linked immunosorbent assay (ELISA). Here, we review our recent studies of human exposure in six African countries; Gambia, Guinea, Kenya, Senegal, Tanzania and Uganda. This data shows the widespread exposure of vulnerable populations to aflatoxin. Geometric mean (95% confidence interval) levels of the biomarker ranged from 9.7 pg/mg (8.2, 11.5) in Ugandan children to 578.5 pg/mg (461.4, 717.6) in Kenyan adolescents during an acute aflatoxicosis outbreak year. We describe how various factors may have influenced the variation in aflatoxin exposure in our studies. Together, these studies highlight the urgent need for measures to reduce the burden of aflatoxin exposure in sub-Saharan Africa.

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Naeem, Iqra, Amir Ismail, Awais Ur Rehman, Zubair Ismail, Shehzadi Saima, Ambreen Naz, Asim Faraz et al. « Prevalence of Aflatoxins in Selected Dry Fruits, Impact of Storage Conditions on Contamination Levels and Associated Health Risks on Pakistani Consumers ». International Journal of Environmental Research and Public Health 19, n^o 6 (14 mars 2022) : 3404. http://dx.doi.org/10.3390/ijerph19063404.

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Dry fruits and nuts are nutritious foods with several health-promoting properties. However, they are prone to contamination with aflatoxins at all stages of production and storage. The present study aimed to determine the natural occurrence of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), and total aflatoxins (AFT) in dates, pistachios, and walnuts collected from four districts of South Punjab (Pakistan), and to assess the associated health risks as estimated by dietary exposure and the Margin of Exposure (MoE) determinations. The contents of AFB1 and AFT in these food products were monitored during storage under three different conditions (open-air, hermetically closed jars, and refrigeration at 4 °C) to determine the most efficient conditions in preventing aflatoxin accumulation. HPLC-fluorescence analysis of 60 samples of these products for aflatoxin contamination showed that 52 (86.7%) samples were contaminated at different levels, with a maximum of 24.2 ng/g. The overall (all samples) mean concentrations of AFB1, AFB2, AFG1, AFG2, and AFT were 3.39 ± 2.96, 1.39 ± 1.68, 1.63 ± 1.48. 1.12 ± 1.23, and 7.54 ± 6.68, respectively. The Estimated Daily Intake (EDI) and MoE of aflatoxins through the consumption of the products ranged from 0.06 ng/kg bw/day to 2.0 ng/kg bw/day and from 84.84 to 2857.13, respectively, indicating that consumers are at high health risk. Significant differences were recorded between aflatoxin levels in the samples stored under different storage conditions, with storage under refrigeration (4 °C) being the most effective in controlling aflatoxin accumulation, although storage in closed jars was also efficient and offers a more flexible alternative to retailers. The findings of the study urge official authorities of Pakistan to implement appropriate regulatory and control measures and surveillance program to alleviate the potential public health risks associated with the consumption of dry fruits and nuts in the scope of their increased consumption.

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Tessema, Masresha, Hugo De Groote, Inge D. Brouwer, Marthe De Boevre, Arnau Vidal Corominas, Barbara J. Stoecker, Edith JM Feskens, Tefera Belachew, Anastasia Karakitsou et Nilupa S. Gunaratna. « Exposure to aflatoxins and fumonisins and linear growth of children in rural Ethiopia : a longitudinal study ». Public Health Nutrition 24, n^o 12 (1 février 2021) : 3662–73. http://dx.doi.org/10.1017/s1368980021000422.

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AbstractObjective:We hypothesise that exposure to aflatoxins and fumonisins, measured in serum, alters protein synthesis, reducing serum protein and insulin-like growth factor 1 (IGF-1), increasing inflammation and infection, leading to child’s linear growth failure.Design:Children 6–35 months, stratified by baseline stunting, were subsampled from an intervention trial on quality protein maize consumption and evaluated at two time-points.Setting:Blood samples and anthropometric data were collected in the pre-harvest (August–September 2015) and post-harvest (February 2016) seasons in rural Ethiopia.Participants:102 children (50 stunted and 52 non-stunted).Results:Proportions of children exposed to aflatoxin G1, aflatoxin G2 and aflatoxin M1 were higher in the pre-harvest (8, 33 and 7, respectively) compared to post-harvest season (4, 28 and 4, respectively). The proportion of children exposed to any aflatoxin was higher in the pre-harvest than post-harvest season (51 % v. 41 %). Fumonisin exposure ranged from 0 % to 11 %. In joint statistical tests, aflatoxin exposure was associated with serum biomarkers of inflammation (C-reactive protein, α-1-glycoprotein) and protein status (transthyretin, lysine, tryptophan), IGF-1 and linear growth (all P < 0·01). However, exposure to specific aflatoxins was not significantly associated with any biomarkers or outcomes (all P > 0·05).Conclusions:Aflatoxin exposure among rural Ethiopian children was high, with large variation between seasons and individual aflatoxins. Fumonisin exposure was low. There was no clear association between aflatoxin exposure and protein status, inflammation or linear growth. A larger study may be needed to examine the potential biological interactions, and the assessment of aflatoxins in food is needed to determine sources of high exposure.

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Shabeer, Saba, Shahzad Asad, Atif Jamal et Akhtar Ali. « Aflatoxin Contamination, Its Impact and Management Strategies : An Updated Review ». Toxins 14, n^o 5 (27 avril 2022) : 307. http://dx.doi.org/10.3390/toxins14050307.

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Aflatoxin, a type of mycotoxin, is mostly produced by Aspergillus flavus and Aspergillus parasiticus. It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops such as cotton, groundnut, maize, and chilies, and causing immense effects on the health of humans and animals. More than eighteen different types of aflatoxins have been reported to date, and among them, aflatoxins B1, B2, G1, and G2 are the most prevalent and lethal. Early detection of fungal infection plays a key role in the control of aflatoxin contamination. Therefore, different methods, including culture, chromatographic techniques, and molecular assays, are used to determine aflatoxin contamination in crops and food products. Many countries have set a maximum limit of aflatoxin contamination (2–20 ppb) in their food and agriculture commodities for human or animal consumption, and the use of different methods to combat this menace is essential. Fungal infection mostly takes place during the pre- and post-harvest stage of crops, and most of the methods to control aflatoxin are employed for the latter phase. Studies have shown that if correct measures are adopted during the crop development phase, aflatoxin contamination can be reduced by a significant level. Currently, the use of bio-pesticides is the intervention employed in many countries, whereby atoxigenic strains competitively reduce the burden of toxigenic strains in the field, thereby helping to mitigate this problem. This updated review on aflatoxins sheds light on the sources of contamination, and the on occurrence, impact, detection techniques, and management strategies, with a special emphasis on bio-pesticides to control aflatoxins.

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Buttinger, G., S. Harbeck et R. Josephs. « The certification of the aflatoxin mass fractions in peanut butter ». World Mycotoxin Journal 1, n^o 3 (1 août 2008) : 283–89. http://dx.doi.org/10.3920/wmj2008.x038.

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In the context of control activities contamination of food and feed with aflatoxins is a frequently observed non compliance. Pistachios, peanuts and products thereof are particularly affected. The Institute for Reference Materials and Measurements has therefore produced a peanut butter material certified for its aflatoxin mass fractions. This certified reference material (CRM) allows for the evaluation of analytical method performance and the assessment of the comparability of results from different laboratories. The CRM was produced using naturally contaminated raw materials to ensure equivalent behaviour compared to samples routinely encountered. The homogeneity and stability of the CRM were thoroughly tested and certified values were determined in an inter-laboratory study. Furthermore, uncertainties of the certified values were assessed including contributions of the homogeneity, stability and certification studies to the combined uncertainty. This newly prepared CRM allows an assessment of trueness of the analytical method at a concentration level corresponding to the legal limits enforced in the European Union. The material has the following certified properties: aflatoxin B1 1.77±0.29 µg/kg, aflatoxin B2 0.48±0.07 µg/kg, aflatoxin G1 0.9±0.4 µg/kg, aflatoxin G2 0.31±0.12 µg/kg and total aflatoxins, as sum of aflatoxins B1, B2, G1 and G2, 3.5±0.5 µg/kg.

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Turner, Paul Craig. « The Molecular Epidemiology of Chronic Aflatoxin Driven Impaired Child Growth ». Scientifica 2013 (2013) : 1–21. http://dx.doi.org/10.1155/2013/152879.

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Aflatoxins are toxic secondary fungal metabolites that contaminate dietary staples in tropical regions; chronic high levels of exposure are common for many of the poorest populations. Observations in animals indicate that growth and/or food utilization are adversely affected by aflatoxins. This review highlights the development of validated exposure biomarkers and their use here to assess the role of aflatoxins in early life growth retardation. Aflatoxin exposure occurs in utero and continues in early infancy as weaning foods are introduced. Using aflatoxin-albumin exposure biomarkers, five major studies clearly demonstrate strong dose response relationships between exposure in utero and/or early infancy and growth retardation, identified by reduced birth weight and/or low HAZ and WAZ scores. The epidemiological studies include cross-sectional and longitudinal surveys, though aflatoxin reduction intervention studies are now required to further support these data and guide sustainable options to reduce the burden of exposure. The use of aflatoxin exposure biomarkers was essential in understanding the observational data reviewed and will likely be a critical monitor of the effectiveness of interventions to restrict aflatoxin exposure. Given that an estimated 4.5 billion individuals live in regions at risk of dietary contamination the public health concern cannot be over stated.

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Nguyen, Thanh Binh, Thi Bich Vu, Hong Minh Pham, Cao Son Tran, Hong Hao Le Thi et Ngoc Thuy Vo Thi. « Detection of Aflatoxins B1 in Maize Grains Using Fluorescence Resonance Energy Transfer ». Applied Sciences 10, n^o 5 (26 février 2020) : 1578. http://dx.doi.org/10.3390/app10051578.

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Aflatoxins are secondary metabolites of Aspergillus flavus and Aspergillus parasiticus. These fungal species are the most dangerous and common toxin group causing food contamination. Aflatoxin has high toxicity and can cause cancer to humans and animals. The quantitative detection of aflatoxin in food, therefore, plays a very important role. However, in practice, due to low concentrations, aflatoxin detection analysis methods need to be highly sensitive and simple to apply. In this report, the fluorescence resonance energy transfer method (FRET) adopts the donor–acceptor interaction of aflatoxin B1. The CdSe/ZnS quantum dot detection of aflatoxin B1 will be presented wherein the aflatoxin B1 concentration can be determined from the changes in fluorescence lifetime or fluorescence intensity. A fluorescence lifetime calibration curve versus aflatoxin B1 concentrations was established. Test results of aflatoxin B1 determination in maize in Vietnam by FRET method are consistent with the results of aflatoxin B1 determination by HPLC based on ppm concentration.

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KACHAPULULA, PAUL W., JULIET AKELLO, RANAJIT BANDYOPADHYAY et PETER J. COTTY. « Aflatoxin Contamination of Dried Insects and Fish in Zambia ». Journal of Food Protection 81, n^o 9 (17 août 2018) : 1508–18. http://dx.doi.org/10.4315/0362-028x.jfp-17-527.

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ABSTRACT Dried insects and fish are important sources of income and dietary protein in Zambia. Some aflatoxin-producing fungi are entomopathogenic and also colonize insects and fish after harvest and processing. Aflatoxins are carcinogenic, immune-suppressing mycotoxins that are frequent food contaminants worldwide. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination of crops in Africa. However, aflatoxin producers associated with dried fish and edible insects in Zambia remain unknown, and aflatoxin concentrations in these foods have been inadequately evaluated. The current study sought to address these data gaps to assess potential human vulnerability through the dried fish and edible insect routes of aflatoxin exposure. Caterpillars (n = 97), termites (n = 4), and dried fish (n = 66) sampled in 2016 and 2017 were assayed for aflatoxin by using lateral flow immunochromatography. Average aflatoxin concentrations exceeded regulatory limits for Zambia (10 μg/kg) in the moth Gynanisa maja (11 μg/kg), the moth Gonimbrasia zambesina (Walker) (12 μg/kg), and the termite Macrotermes falciger (Gerstacker) (24 μg/kg). When samples were subjected to simulated poor storage, aflatoxins increased (P < 0.001) to unsafe levels in caterpillars (mean, 4,800 μg/kg) and fish (Oreochromis) (mean, 23 μg/kg). The L strain morphotype of A. flavus was the most common aflatoxin producer on dried fish (88% of Aspergillus section Flavi), termites (68%), and caterpillars (61%), with the exception of Gynanisa maja, for which A. parasiticus was the most common (44%). Dried fish and insects supported growth (mean, 1.3 × 109 CFU/g) and aflatoxin production (mean, 63,620 μg/kg) by previously characterized toxigenic Aspergillus section Flavi species, although the extent of growth and aflatoxigenicity depended on specific fungus-host combinations. The current study shows the need for proper storage and testing of dried insects and fish before consumption as measures to mitigate human exposure to aflatoxins through consumption in Zambia.

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Akinola, Stephen Abiola, Collins Njie Ateba et Mulunda Mwanza. « Polyphasic Assessment of Aflatoxin Production Potential in Selected Aspergilli ». Toxins 11, n^o 12 (26 novembre 2019) : 692. http://dx.doi.org/10.3390/toxins11120692.

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This study investigated the aflatoxin production potentials of selected fungi using a polyphasic approach. Internally transcribed spacer region of the fungi was amplified using the polymerase chain reaction. Forty-five Aspergillus strains were further assessed for aflatoxin production using the conventional methods such as growth on yeast extract sucrose, β-cyclodextrin neutral red desiccated coconut agar (β-CNRDCA); expression of the aflatoxin regulatory genes and the use of both thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A large proportion (82.22%) of the isolates harbored the Nor-1 gene while 55.56%, 68.89%, and 80% possessed the ver-1, omt-A, and aflR genes, respectively. All 100% the isolates harbored the aflJ gene. Twenty-three isolates were positive for aflatoxin production based on the yeast extract sucrose medium (YES) test; ammonium vapor test (51%), yellow pigment production (75.5%), and β-CNRDCA tests; and blue/green fluorescence (57.7%). Based on TLC detection 42.2% produced aflatoxins while in the HPLC, total aflatoxin (AFTOT) production concentrations ranged from 6.77–71,453 µg/g. Detectable aflatoxin B1 (AFB1) concentrations obtained from the HPLC ranged between 3.76 and 70,288 µg/g; 6.77 and 242.50 µg/g for aflatoxin B2 (AFB2); 1.87 and 745.30 µg/g for aflatoxin G1 (AFG1); and 1.67 and 768.52 µg/g for aflatoxin G2 (AFG2). AFTOT contamination levels were higher than European Union tolerable limits (4 µg/kg). The regression coefficient was one (R2 = 1) while significant differences exist in the aflatoxin concentrations of Aspergillus (p ≤ 0.05). This study reports the potentials of Aspergillus oryzae previously known as a non-aflatoxin producer to produce AFG1, AFG2, AFB1, and AFB2 toxins. Aspergillus species in feedlots of animals reared for food are capable of producing aflatoxins which could pose hazards to health.

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Larionova, D., I. Goryacheva, C. Van Peteghem et S. De Saeger. « Thin-layer chromatography of aflatoxins and zearalenones with β-cyclodextrins as mobile phase additives ». World Mycotoxin Journal 4, n^o 2 (1 janvier 2011) : 113–17. http://dx.doi.org/10.3920/wmj2010.1267.

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The conditions of thin-layer chromatography separation of related aflatoxins and zearalenones in the presence of β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin were studied. Effects of the stationary phase and mobile phase composition were investigated. Analytical conditions for the separation and simultaneous semi-quantitative fluorescence detection of aflatoxins B1, B2, G1 and G2, zearalenone and α-zearalenol on normal-phase plates (silica gel, polyamide) and reversed-phase plates (C18) with cyclodextrin modified mobile phase were optimised. The limit of quantification was found 2 ng per spot for aflatoxin G1 and aflatoxin B2, 3.5 ng for aflatoxin B1 and aflatoxin G2 and 100 ng per spot for zearalenone and α-zearalenol. Addition of cyclodextrins to the mobile phase allowed a decrease in the amount of toxic solvents, and improved separation characteristics, but did not improve the limit of quantification.

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Siruguri, Vasanthi, Srinivasu Kurella et Nupur Bharadwaj. « Assessment of Aflatoxin Contamination from Discoloured Kernels in Ready-To-Eat Processed Groundnut Products ». Indian Journal of Nutrition and Dietetics 55, n^o 4 (9 octobre 2018) : 397. http://dx.doi.org/10.21048/ijnd.2018.55.4.21510.

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The present study was attempted to assess the extent of aflatoxin contamination from presence of discoloured kernels (DKs) in ready-to-eat (RTE) processed whole groundnut products sold in Hyderabad city in southern India. A total of 34/56 fried (FG) and roasted and salted groundnut (RSG) samples were examined for the presence of DKs. DKs were segregated from the samples and subjected to aflatoxin analysis either as single DK or pooled DKs using HPLC methods. The aflatoxin content in the RTE samples was computed from the aflatoxin levels determined in the segregated DKs as well as in the non-discoloured kernels (NDKs) and ingredients used for coating such as flour and spices. Analysis of 77 single DKs indicated presence of aflatoxins in 31% of the DKs at levels ranging from 0.007 to 1383.4 μg/g. Analysis of 17 pooled DK samples indicated presence of aflatoxins in 13 pooled DKs at levels ranging from 0.142-357.3 μg/ pooled DKs. The total aflatoxin content in the RTE samples calculated from aggregate of aflatoxin levels in DKs, NDKs and other components ranged from 0.001 to 2.779 μg/g sample respectively and was contributed mostly by DKs (90%). Aflatoxin was not detected in 22 samples that did not contain DKs. Presence of DKs in RTE groundnut products for direct human consumption can become potential sources of aflatoxin exposure to the consumer and methods to prevent their entry into processed foods containing whole kernels at post processing is urgently required.

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El-Nagerabi, Saifeldin A. F., Mohammed S. R. Al-Maqbali, Khalid M. S. Alabri et Abdulkadir E. Elshafie. « An in Vitro Antifungal and Antiaflatoxigenic Properties of Commiphora myrrha and Prunus mahaleb ». Journal of Food Research 10, n^o 6 (21 novembre 2021) : 10. http://dx.doi.org/10.5539/jfr.v10n6p10.

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Aflatoxins and especially aflatoxin B, are the devastating contaminant of food and feed products with hazardous effects to mankind and his domestic animals. These investigations were set to evaluate the effect of various levels of Commiphora myrrha resin (1.0, 1.25, 2.25, and 3.25 g/100 ml) and Prunus mahaleb seed extract (0.75, 1.5, 2.5, and 3.5 g/100 ml) on the growth and aflatoxin secretion by two aflatoxigenic strains of Aspergillus flavus and A. parasiticus. The two plant extracts significantly (p<0.05) decreased aflatoxin secretion, and inhibited the fungal growth. Resin of C. myrrha displayed 51.9-95.7% reduction in total aflatoxin secretion by A. flavus, and 46.9-92% for A. parasiticus, and Seed extract of P. mahaleb decreased aflatoxin up to 53.7-95.8% and 40-94.7%, respectively. The inhibition of aflatoxin B (B1 and B2) by myrrh resin and seed extract of mahaleb ranged between 51.7-93.5, 50-93.6% (A. flavus) and 39.5-89.7%, 37.9-93% (A. parasiticus). The mycelial dry weight of A. flavus and A. parasiticus ws decreased up to 46.1-58.7%, 28.9-51.3% (Myrrh resin), and between 45-56.9%, 33.3-55.9% (Mahaleb seed extract). Nonetheless, the two plant extracts did not detoxify aflatoxin B1. Therefore, it apparent that the resin of C. myrrha and seed extract of P. mahaleb affected the biosynthesis pathway of aflatoxins. Thus, they can be recommended as effective natural plant biopreservative against aflatoxin contamination of food and feed products.

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Beatrice Mukandungutse, Isabelle, James K. Tuitoek, Anthony M. King’ori et Meshack A. Obonyo. « The Effect of Fermented Aflatoxins Contaminated Feed on Digestibility and Performance of Broiler Chickens ». ANIMAL PRODUCTION 22, n^o 1 (17 septembre 2020) : 55–60. http://dx.doi.org/10.20884/1.jap.2020.22.1.3.

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Poultry is susceptible to mycotoxicoses caused by aflatoxins. Two experiments were carried out, where twenty-four, 28days old and 144 one-day-old broilers were assigned to six diets respectively. The diets were: diet1 (no aflatoxin and not fermented), diet2 (no aflatoxin and fermented without yeast), diet3 (no aflatoxin and fermented with yeast), diet4 (contained aflatoxin and not fermented), diet5 (contained aflatoxin and fermented without yeast) and diet6 (contained aflatoxin fermented with yeast). The aflatoxins were 20.034 and 30.08ppb for the first and second experiments respectively. In the first experiment, each diet was assigned to 4 chickens for 7days adaptation and 7days for feces and leftover collection. The feces were oven dried for the determination of dry matter digestibility (DMD), metabolizable energy (ME) and nitrogen (MN). In the second experiment, each diet was assigned to six chicks, replicated 4 times for 21days. Leftovers and mortalities were recorded daily and chicks were weighed on a weekly basis. The results showed that DMD and MN were significantly (p<0.05) affected by fermentation. Natural fermentation improved DMD of the clean and contaminated diets. No difference found in feed intake and body weight gain. However, gain: feed ratio was significantly (p=0.048) better in broilers fed diets fermented naturally. The mortality rate was 75.0% in chicks fed on aflatoxin diet which was not fermented. Therefore, natural fermentation is the best method of improving the quality of aflatoxin contaminated feed for broilers.

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Ojiambo, Peter S., Paola Battilani, Jeffrey W. Cary, Burt H. Blum et Ignazio Carbone. « Cultural and Genetic Approaches to Manage Aflatoxin Contamination : Recent Insights Provide Opportunities for Improved Control ». Phytopathology® 108, n^o 9 (septembre 2018) : 1024–37. http://dx.doi.org/10.1094/phyto-04-18-0134-rvw.

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Aspergillus flavus is a morphologically complex species that can produce the group of polyketide derived carcinogenic and mutagenic secondary metabolites, aflatoxins, as well as other secondary metabolites such as cyclopiazonic acid and aflatrem. Aflatoxin causes aflatoxicosis when aflatoxins are ingested through contaminated food and feed. In addition, aflatoxin contamination is a major problem, from both an economic and health aspect, in developing countries, especially Asia and Africa, where cereals and peanuts are important food crops. Earlier measures for control of A. flavus infection and consequent aflatoxin contamination centered on creating unfavorable environments for the pathogen and destroying contaminated products. While development of atoxigenic (nonaflatoxin producing) strains of A. flavus as viable commercial biocontrol agents has marked a unique advance for control of aflatoxin contamination, particularly in Africa, new insights into the biology and sexuality of A. flavus are now providing opportunities to design improved atoxigenic strains for sustainable biological control of aflatoxin. Further, progress in the use of molecular technologies such as incorporation of antifungal genes in the host and host-induced gene silencing, is providing knowledge that could be harnessed to develop germplasm that is resistant to infection by A. flavus and aflatoxin contamination. This review summarizes the substantial progress that has been made to understand the biology of A. flavus and mitigate aflatoxin contamination with emphasis on maize. Concepts developed to date can provide a basis for future research efforts on the sustainable management of aflatoxin contamination.

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