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1.
J Agric Food Chem ; 69(45): 13608-13617, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34747604

RESUMO

Aspergillus flavus is saprophytic soil fungus that contaminates seed crops with the carcinogenic secondary metabolite aflatoxin, posing a significant threat to humans and animals. Ferrous sulfate is a common iron supplement that is used to the treatment of iron-deficiency anemia. Here, we identified an unexpected inhibitory role of ferrous sulfate on A. flavus. With specific fluorescent dyes, we detected several conidial ferroptosis hallmarks in conidia under the treatment of 1 mM Fe2+, including nonapoptosis necrosis, iron-dependent, lipid peroxide accumulation, and ROS burst. However, unlike traditional ferroptosis in mammals, Fe2+ triggered conidial ferroptosis in A. flavus was regulated by NADPH oxidase (NOXs) activation instead of Fenton reaction. Transcriptomic and some other bioinformatics analyses showed that NoxA in A. flavus might be a potential target of Fe2+, and thus led to the occurrence of conidial ferroptosis. Furthermore, noxA deletion mutant was constructed, and both ROS generation and conidial ferroptosis in ΔnoxA was reduced when exposed to Fe2+. Taken together, our study revealed an exogenous Fe2+-triggered conidial ferroptosis pathway mediated by NoxA of A. flavus, which greatly contributes to the development of an alternative strategy to control this pathogen.


Assuntos
Aflatoxinas , Ferroptose , Animais , Aspergillus flavus/genética , Humanos , Ferro , NADPH Oxidases , Esporos Fúngicos
2.
Shokuhin Eiseigaku Zasshi ; 62(5): 148-156, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34732640

RESUMO

Aflatoxins (AFs) are known to be oncogenic mycotoxins. This study investigated the mitigation effects of lactic acid bacteria (LAB) isolated from four types of vegetable, cucumber, Chinese cabbage, Japanese radish and eggplant, which are used to make Japanese traditional fermented pickles, on AFs. Using aflatoxin M1 (AFM1) binding assay for screening, four representative strains were selected (one from each vegetable) from total 94 LAB strains, based on the highest binding ratio. The ranges of the binding ratio of these representative strains to aflatoxin B1 (AFB1), aflatoxin B2, aflatoxin G1, aflatoxin G2 and AFM1 were 57.5%-87.9% for the LAB strain derived from cucumber, 18.9%-43.9% for the LAB strain derived from Chinese cabbage, 26.4%-41.7% for the LAB strain derived from Japanese radish, and 15.0%-42.6% for the LAB strain derived from eggplant. The strains isolated from cucumber, Chinese cabbage, Japanese radish and eggplant were identified as Lactococcus lactis subsp. lactis, Weissella cibaria, Leuconostoc mesenteroides and Leu. mesenteroides, respectively. An in vitro binding assay of the four strains under acidic conditions showed that the number of living bacteria decreased, while the binding ratio increased in some strains, suggesting that the LAB maintained their capacity to bind aflatoxins even in an environment that imitated the stomach. An in vivo experiment using L. lactis subsp. lactis derived from cucumber revealed that the bacteria significantly inhibited the absorption of AFB1 into blood. These results showed that the LAB used for Japanese vegetable pickles was an effective binding agent of AFs and suggested that they might play a role in mitigating AF absorption.


Assuntos
Aflatoxinas , Lactobacillales , Weissella , Verduras
3.
Int J Food Microbiol ; 359: 109428, 2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34655921

RESUMO

For a long period, Nelumbinis semen has been widely used as a medicinal and edible product. However, it is susceptible to contamination with toxigenic fungi and aflatoxins during the growth, collection, transportation, and storage processes, causing serious health threats to humans and huge economic losses. Effectively monitoring the fungal communities is of great importance to avoid aflatoxins contamination in Nelumbinis semen. High-throughput sequencing (HTS) is a new technology to evaluate fungal communities so as to overcome the limitations of the traditional cultural ways. In this study, the ITS2 based Illumina-MiSeq platform was developed to evaluate the fungal communities in normal and moldy Nelumbinis semen by using the HTS technology. Two different primer pairs were introduced to compare their performance in amplifying the target gene. The primer pair that produced more reads was selected to analyze the results. In all the nine tested Nelumbinis semen samples, 2 phyla, 5 classes, 6 orders, 8 families, 9 genera and 4 species were detected. A total of 9 genera were spotted, of which, Aspergillus (0.04%-72.93%) and Rhizopus (0.002%-48.12%) were the most dominant. ANOISM analysis showed no significant differences in the normal and moldy groups. The use of HTS technology can detect the fungal communities in complex Nelumbinis semen samples, providing an early warning for toxigenic fungi and aflatoxins contamination to warrant their quality and safety.


Assuntos
Aflatoxinas , Medicamentos de Ervas Chinesas , Micobioma , Aflatoxinas/análise , Fungos/genética , Sequenciamento de Nucleotídeos em Larga Escala
4.
Molecules ; 26(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34641298

RESUMO

Pistachios are one of the types of tree nut fruits with the highest mycotoxin contamination, especially of aflatoxins, worldwide. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method that was followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC-ToF-MS) for the determination of mycotoxins in pistachios. Different approaches to dispersive solid phase extraction as a clean-up method for high lipid matrices were evaluated. For this, classic sorbents such as C18 (octadecyl-modified silica) and PSA (primary secondary amine), and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide), were used. The QuEChERS method, followed by Z-Sep d-SPE clean-up, provided the best analytical performance for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2) in pistachios. The method was validated in terms of linearity, sensitivity, repeatability, interday precision and recovery; it achieved good results according to criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to real samples and the results show that pistachios that are available in Portuguese markets are safe from mycotoxins that are of concern to human health.


Assuntos
Aflatoxinas/análise , Contaminação de Alimentos/análise , Pistacia/química , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Espectrometria de Massas , Micotoxinas/análise , Extração em Fase Sólida
5.
J Agric Food Chem ; 69(38): 11451-11460, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34524794

RESUMO

The objective of the present study was to investigate the bioavailability of aflatoxins (AFs) from fish, and chicken and rabbit livers using an in vitro dialyzability approach. Ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to assess the aflatoxin content in samples, as well as in dialyzate and residue fractions after the in vitro procedure. A vortex-assisted dispersive liquid-liquid microextraction (VALLME) technique was used for preconcentrating AFs before determination. Raw samples showed bioavailability ratios of 41-45% for aflatoxin B1 (AFB1), 28-38% for aflatoxin B2 (AFB2), and 42% for aflatoxin G2 (AFG2). Aflatoxin G1 (AFG1) was not detected. The culinary process (steaming or grilling) was found to change AFs' bioavailability (higher bioavailability ratios were found in cooked samples). AFB2 was found to be transformed into other compounds during the in vitro process, and the presence of AFB2 and AFB2 transformation/degradation products was investigated and confirmed by high-resolution mass spectrometry (HRMS).


Assuntos
Aflatoxinas , Espectrometria de Massas em Tandem , Aflatoxina B1 , Aflatoxinas/metabolismo , Animais , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos/análise , Fígado/metabolismo , Coelhos
6.
Int J Food Microbiol ; 357: 109368, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34481126

RESUMO

In this study, the effect of in-package gas composition on growth and aflatoxin production of toxigenic Aspergillus flavus was investigated. For this purpose, semi-dried red pepper samples and potato dextrose agar media with different pH values (3.5, 5.6, 7.0 and 9.0) were inoculated with A. flavus and packaged under different gas atmospheres (air, 100% N2, 70% N2 + 30% CO2 and 100% CO2). The growth of the fungus was monitored during storage at 25 °C for 8 days and the aflatoxin levels produced were determined at the end of storage. The highest growth rate was observed in the medium at pH 9.0 and the highest toxin production was in the medium at pH 5.6. Slowdowns up to 55.6% and 28.0% in the growth of A. flavus in the culture medium and red pepper were observed when packaging under 100% N2 was employed. It was found that 70% N2 + 30% CO2 atmosphere was more effective than 100% N2 in inhibiting the growth of A. flavus in red peppers; however, the difference between the aflatoxin levels produced in the samples packaged under these gas compositions was not significant (p > 0.05). CO2 concentrations higher than 90% in the package were quite effective against A. flavus resulting in 60% and 99% reductions in the growth and aflatoxin production of the fungus in red pepper.


Assuntos
Aflatoxinas , Capsicum , Aflatoxina B1 , Aspergillus flavus , Meios de Cultura
7.
Med Mycol J ; 62(3): 47-52, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34471034

RESUMO

Aflatoxin produced by Aspergillus flavus is known to be strongly related to liver injury (hepatocellular carcinoma) and immune system damage involving leukocytes. This toxin suppresses both the cell-mediated immune system and macrophage function, and decreases the production of complement and interferon molecules. PURPOSE: To evaluate the presence of aflatoxin in infectious lesions as well as how the toxin is taken up by leukocytes. METHOD: Pathological specimens from a patient who died from aspergillosis caused by aflatoxin-producing A. flavus were used. Anti-aflatoxin B1 antibody was reacted with paraffin-embedded lesion specimens from the heart, kidney, and thyroid gland of the patient and observed microscopically. RESULT: Positive reactions were detected in fungal elements and leukocytes (neutrophils and macrophages) in inflammatory lesions. CONCLUSION: Within the patient's body, A. flavus likely produced aflatoxin, which then was taken up by neutrophils and macrophages.These results suggest that leukocyte function and the immune mechanism are locally suppressed by aflatoxin.


Assuntos
Aflatoxinas , Aspergilose , Aflatoxina B1 , Aspergillus flavus , Fungos , Humanos
8.
Int J Food Microbiol ; 357: 109369, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34474198

RESUMO

Aspergillus parasiticus is a pre-harvest and postharvest pathogen that is known to produce aflatoxin; however, it is less studied compared to A. flavus. Inappropriate storage conditions are a cause of food spoilage and growth of mycotoxigenic fungi especially in low moisture foods thus constituting hazards to health. Hence, this study investigated the behaviour of A. parasiticus on aflatoxin production in inoculated wheat flour as influenced by storage conditions using the response surface methodology. Twenty experimental runs consisting of independent variables (incubation temperature (A), time (B) and (C) moisture content) and responses (aflatoxin concentrations, i.e., AFB1, AFB2, AFG1, AFG2 and AFTOT) were developed. A central composite face-centered design was used with lower and upper limits: A (25-35 °C), B (7-15 days) and C (15-25%), while the non-inoculated wheat flour served as the negative control. Aflatoxin production was determined using High Performance Liquid Chromatography (HPLC) according to standard procedures. Numerical and graphical process variables were optimized, adequate models were predicted and optimal point prediction for aflatoxin concentration was determined. AFG1 concentrations ranged from 1.10 to 360.06 µg/g, AFG2 (0.91-446.94 µg/g), AFB2 (7.95-488.77 µg/g), AFB1 (17.21-20,666.6 µg/g) and AFTOT (15.91-21,851.09 µg/g). Aflatoxin concentration increased with increase in 'B' and 'A' but decreased with prolonged increase in 'B'. AFB1 concentrations in A. parasiticus inoculated wheat flour increased at prolonged 'B' and 'A' at constant moisture (12.09%). A reduced cubic model was significantly adequate to describe the relationship between process variables and responses (AFG1 and AFG2), cubic model (AFB1 and AFTOT) and a transformed square root cubic model for AFG2 concentrations (p ≤ 0.05). 'A' influenced AFG1 production more than 'C' while 'C' and 'A' had no significant effect on AFG2 production. Process variables 'AB' influenced AFB2 concentrations more than 'C' while 'A' had a more significant effect on the AFTOT production than 'B' (p ≤ 0.05). The predicted (R2) and adjusted coefficient of regression (adj R2) were in reasonable agreement. After optimal point prediction and validation, minimum aflatoxin concentration ≤ 0 µg/g could be achieved at the predicted conditions (A = 30.42 °C, B = 10.58 days and C = 14.49%) except in AFG2 (3.33 µg/g).


Assuntos
Aflatoxinas , Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus , Aspergillus flavus , Farinha , Triticum
9.
Talanta ; 235: 122709, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517582

RESUMO

Herein, a high-performance screening tool for the selective and sensitive monitoring of aflatoxins is reported based on their great quenching effect on the blue emission of graphene quantum dots (GQDs). To make a specific determination, a pre-extraction method was also developed using a new nano-sorbent based on the surface-imprinted Zr metal-organic framework on the magnetic graphene oxide (MGO/MOF-808@MIP). The adsorbing efficiency of the prepared composite was remarkably higher than the pristine MOF-808 or bare GO. The presence of GO nanosheets, as well as nanoporous MOF-808 provided a high accessible surface area to form the MIP layer. It provided a great number of MIP sites for high efficient and rapid extraction of aflatoxins. The presence of magnetic nanoparticles in the structure of nanocomposite also facilitated the extraction process using a magnetic solid-phase extraction (MSPE) system. The combination of this specific and high-performance extraction with simple fluorometric detection caused a potent screening tool for aflatoxins. The method was able to monitor the total aflatoxins content of food samples with a linear range of 0.05-8 ng mL-1, which was more sensitive than the fluorometric system without extraction (5-500 ng mL-1). More developments were made by the application of a high-performance liquid chromatography (HPLC) method for the discrimination of the extracted aflatoxins. The system showed high sensitivity and selectivity and was able to detect different aflatoxins with an acceptable resolution.


Assuntos
Aflatoxinas , Grafite , Adsorção , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Fenômenos Magnéticos , Extração em Fase Sólida
10.
J Agric Food Chem ; 69(40): 11971-11981, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34591470

RESUMO

Biotin is an important enzyme cofactor that plays a key role in all three domains. The classical bifunctional enzyme BioDA in eukaryotes (such as Aspergillus flavus and Arabidopsis thaliana) is involved in the antepenultimate and penultimate steps of biotin biosynthesis. In this study, we identified a A. flavus bifunctional gene bioDA which could complement both Escherichia coli ΔEcbioD and ΔEcbioA mutants. Interestingly, the separated domain of AfBioD and AfBioA could, respectively, fuse with EcBioA and EcBioD well and work together. What is more, we found that BioDA was almost localized to the mitochondria in A. flavus, as shown by N-terminal red fluorescent protein tag fusion. Noteworthy, the subcellular localization of AfBioDA is never affected by common environmental stresses (such as hyperosmotic stress or oxidative stress). The knockout strategy demonstrated that the deletion of AfbioDA gene from the chromosome impaired the biotin de novo synthesis pathway in A. flavus. Importantly, this A. flavus mutant blocked biotin production and decreased its pathogenicity to infect peanuts. Based on the structural comparison, we found that two inhibitors (amiclenomycin and gemcitabine) could be candidates for antifungal drugs. Taken together, our findings identified the bifunctional AfbioDA gene and shed light on biotin biosynthesis in A. flavus.


Assuntos
Aflatoxinas , Arabidopsis , Arabidopsis/metabolismo , Aspergillus flavus/genética , Aspergillus flavus/metabolismo , Vias Biossintéticas , Biotina , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Virulência
11.
Appl Microbiol Biotechnol ; 105(18): 6871-6886, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34477940

RESUMO

Aspergillus flavus is a notorious saprophytic fungus that compromises the quantity and quality of postharvest grains and produces carcinogenic aflatoxins. The natural compound hexanal disrupts cell membrane synthesis and mitochondrial function and induces apoptosis in A. flavus; here, we investigated the molecular mechanisms underlying these effects. The minimum inhibition and fungicidal concentration (MIC and MFC) of hexanal against A. flavus spores were 3.2 and 9.6 µL/mL, respectively. Hexanal exposure resulted in abnormal spore morphology and early spore apoptosis. These changes were accompanied by increased reactive oxygen species production, reduced mitochondrial membrane potential, and DNA fragmentation. Transcriptomic analysis revealed that hexanal treatment greatly altered the metabolism of A. flavus spores, including membrane permeability, mitochondrial function, energy metabolism, DNA replication, oxidative stress, and autophagy. This study provides novel insights into the mechanism underlying the antifungal activity of hexanal, suggesting that hexanal can be used an anti-A. flavus agent for agricultural applications. KEY POINTS: • Hexanal exposure resulted in abnormal spore morphology. • The apoptotic characteristics of A. flavus were induced after hexanal treatment. • Hexanal could change the expression of key A. flavus growth-related genes.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/metabolismo , Aldeídos , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Apoptose , Mitocôndrias , Esporos Fúngicos/metabolismo
12.
J Hazard Mater ; 416: 125845, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492798

RESUMO

Aflatoxins (AFs) are the extremely hazardous metabolites (carcinogens) that are sporadically observed in crops, and these toxic chemicals are indeed lethal to the health of living organisms including human beings. Thus, AF contaminated food waste needs to be disposed as an environmentally benign way, not releasing it into the environment. This study offered a sustainable disposal and valorization platform for AF contaminated food. Peanut was used as a model food waste, because AF is readily appeared in the peanut during its harvesting, cultivation, storage, transportation process. As the valorization platform, non-catalytic transesterification of AF contaminated peanut was employed to convert it to biodiesel (BD). From the process, lipid in AF contaminated peanut is converted into BD (95.2 wt% yield) at 365°C for 1 min. Since the boiling points of BD and AF are significantly different, this process could also resolve the separation problem of AF (180 °C) from BD (≥ 330 °C) during the transesterification reaction. As a comparison study, alkali-catalyzed reaction was done. The alkali-catalyzed one required a pretreatment process to extract peanut oil for transesterification. The highest yield was 67.8 wt% yield after 6 h of reaction at 65 °C.


Assuntos
Aflatoxinas , Eliminação de Resíduos , Arachis , Biocombustíveis , Esterificação , Alimentos , Humanos
13.
Artigo em Inglês | MEDLINE | ID: mdl-34574455

RESUMO

Eastern herbal medicines (HMs) are plant-derived naturally occurring substances with minimum or no industrial processing that have long been used in traditional medicine. Aflatoxins are frequent contaminants of plants. Therefore, these mycotoxins are likely to contaminate HMs and pose a health risk to individuals using them on a regular basis as preventive or curative treatments of various diseases. The present study aimed to determine aflatoxin levels in the most popular Pakistani HM formulations and to assess the health risk associated with the intake of aflatoxins. A total of 400 samples of HM formulations collected from four districts of Punjab were analyzed for the quantification of aflatoxins, out of which 52.5% were found to be contaminated. The average daily dose (ADD) of AFB1 and AFs through the intake of HM formulations ranged between 0.00483 and 0.118 ng/kg bw/day and between 0.00579 and 1.714 ng/kg bw/day, respectively. The margin of exposure (MOE) and population cancer risk ranged from 99.49 to 29378.8 and from 0.00011 to 0.0325 liver cancer cases/105 individuals/year (0.0075-2.455 liver cancer cases/105 individuals/75 years), respectively. Despite the low exposure to aflatoxins from HM formulations in the four studied Punjab (Pakistan) districts, the frequent contamination of the analyzed samples suggests that official measures should be considered to manage the associated risk.


Assuntos
Aflatoxinas , Neoplasias Hepáticas , Aflatoxinas/análise , Contaminação de Alimentos/análise , Humanos , Paquistão , Medição de Risco
14.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445674

RESUMO

Background: DNA methylation is an epigenetic control mechanism that may be altered by environmental exposures. We have previously reported that in utero exposure to the mycotoxin and liver carcinogen aflatoxin B1 from the maternal diet, as measured using biomarkers in the mothers' blood, was associated with differential DNA methylation in white blood cells of 6-month-old infants from The Gambia. Methods: Here we examined aflatoxin B1-associated differential DNA methylation in white blood cells of 24-month-old children from the same population (n = 244), in relation to the child's dietary exposure assessed using aflatoxin albumin biomarkers in blood samples collected at 6, 12 and 18 months of age. HM450 BeadChip arrays were used to assess DNA methylation, with data compared to aflatoxin albumin adduct levels using two approaches; a continuous model comparing aflatoxin adducts measured in samples collected at 18 months to DNA methylation at 24 months, and a categorical time-dose model that took into account aflatoxin adduct levels at 6, 12 and 18 months, for comparison to DNA methylation at 24 months. Results: Geometric mean (95% confidence intervals) for aflatoxin albumin levels were 3.78 (3.29, 4.34) at 6 months, 25.1 (21.67, 29.13) at 12 months and 49.48 (43.34, 56.49) at 18 months of age. A number of differentially methylated CpG positions and regions were associated with aflatoxin exposure, some of which affected gene expression. Pathway analysis highlighted effects on genes involved with with inflammatory, signalling and growth pathways. Conclusions: This study provides further evidence that exposure to aflatoxin in early childhood may impact on DNA methylation.


Assuntos
Aflatoxina B1/efeitos adversos , Metilação de DNA/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Experiências Adversas da Infância , Aflatoxinas/efeitos adversos , Aflatoxinas/análise , Aflatoxinas/sangue , Albuminas/análise , Pré-Escolar , DNA/metabolismo , Metilação de DNA/genética , Epigênese Genética/genética , Epigenômica/métodos , Feminino , Gâmbia/epidemiologia , Humanos , Lactente , Leucócitos/metabolismo , Masculino
15.
Curr Microbiol ; 78(10): 3674-3685, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34398304

RESUMO

Many agricultural products are susceptible to contamination by aflatoxin-producing species from Aspergillus section Flavi. The objectives of this study were to determine the occurrence of Aspergillus section Flavi in four agricultural products, such as pistachio, walnut, hazelnut, and dried fruits, collected from market and retail shops in various areas of Kerman County and obtain information on the relationships between isolation source and ability to produce sclerotia and potential for aflatoxin production. Aspergillus species were identified based on morphological characteristics as well as subsequent sequencing of the parts of the ß-tubulin and calmodulin genes. From 207 isolated strains, the following species were identified: A. flavus, A. tamarii A. nomius, A. parasiticus, A. arachidicola, A. caelatus, A. pseudotamarii, and A. leporis. To the best of our knowledge, this is the first report of A. pseudotamarii and A. arachidicola with the potential to produce aflatoxins from dried apricots and hazelnuts, respectively. Sclerotial type was significantly different between isolates from different isolation sources. From 192 tested isolates, 38% were aflatoxin producer from which 5% were scored as strong aflatoxin producers and 33% as average aflatoxin producers. A significant difference in the population of aflatoxin-producing strains across the isolation sources was observed which may reflect host adaptation and thereby different vulnerabilities to aflatoxin-producing species among the examined products.


Assuntos
Aflatoxinas , Micotoxinas , Aspergillus/genética , Aspergillus flavus
16.
Artigo em Inglês | MEDLINE | ID: mdl-34360308

RESUMO

Aflatoxins (AFs) are secondary metabolites toxic to humans as well as animals. The environmental conditions, conventional agricultural practices, and illiteracy are the main factors which favor the production of AFs in food and feed. In the current study 744 samples of vegetable seeds and oils (soybean, sunflower, canola, olive, corn, and mustard) were collected and tested for the presence of aflatoxin B1 (AFB1) and total AFs. Liquid-liquid extraction was employed for the extraction of AFs from seeds and oil samples. Reverse phase high performance liquid chromatography equipped with fluorescence detection was used for the analysis. The results have shown that 92 (56.7%) samples of imported and 108 (57.0%) samples of local edible seeds were observed to be contaminated with AFs. All samples of edible seeds have AFB1 levels greater than the proposed limit set by the European Union (EU, 2 µg/kg) and 12 (7.40%) samples of imported seeds and 14 (7.40%) samples of local seeds were found in the range ≥ 50 µg/kg. About 78 (43.3%) samples of imported edible oil and 103 (48.3%) sample of local edible oil were observed to be positive for AFs. Furthermore, 16 (8.88%) and six (3.33%) samples of imported vegetable oil have levels of total AFs in a range (21-50 µg/kg) and greater than 50 µg/kg, respectively. The findings indicate significant differences in AFs levels between imported and local vegetable oil samples (t = 22.27 and p = 0.009) at α = 0.05 and a significant difference in AFs levels were found between vegetable seeds and oil samples (t = -17.75, p = 0.009) at α = 0.05. The highest dietary intake was found for a local sunflower oil sample (0.90 µg/kg/day) in female individuals (16-22 age group). The results have shown considerably high levels of AFB1 and total AFs in seeds and oil samples and emphasise the need to monitor carefully the levels of these toxic substances in food and feed on regular basis.


Assuntos
Aflatoxinas , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão , Ingestão de Alimentos , Feminino , Contaminação de Alimentos/análise , Humanos , Paquistão , Óleos Vegetais , Sementes/química , Verduras
17.
Food Chem ; 365: 130409, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34256225

RESUMO

A new, green, and cost-effective magnetic solid-phase extraction of aflatoxins and ochratoxins from edible vegetable oils samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes (PDA@Fe3O4-MWCNTs) as the absorbent. PDA@Fe3O4-MWCNTs nanomaterials were prepared by chemical co-precipitation and in situ oxidation and self-polymerization of dopamine and was characterized. Factors affecting MSPE and the adsorption behavior of the adsorbent to mycotoxins were studied, and the optimal extraction conditions of MSPE and the complexity of the adsorption process were determined. Based on this, the magnetic solid-phase extraction-high-performance liquid chromatography-fluorescence detection method (MSPE-HPLC-FLD) was established for determining six mycotoxins [aflatoxin B1 (AFB1), AFB2, AFG1, and AFG2, and ochratoxin A (OTA) and OTB)] in vegetable oils. The recovery was 70.15%~89.25%, and RSD was ≤6.4%. PDA@Fe3O4-MWCNTs showed a high affinity toward aflatoxins and ochratoxins, allowing selective extraction and quantification of aflatoxins and ochratoxins from complex sample matrices.


Assuntos
Aflatoxinas , Nanotubos de Carbono , Ocratoxinas , Adsorção , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão , Dopamina , Contaminação de Alimentos/análise , Fenômenos Magnéticos , Ocratoxinas/análise , Óleos Vegetais , Verduras
18.
Molecules ; 26(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205651

RESUMO

High-pressure processing (HPP) has emerged over the last 2 decades as a good alternative to traditional thermal treatment for food safety and shelf-life extension, supplying foods with similar characteristics to those of fresh products. Currently, HPP has also been proposed as a useful tool to reduce food contaminants, such as pesticides and mycotoxins. The aim of the present study is to explore the effect of HPP technology at 600 MPa during 5 min at room temperature on alternariol (AOH) and aflatoxin B1 (AFB1) mycotoxins reduction in different juice models. The effect of HPP has also been compared with a thermal treatment performed at 90 °C during 21 s. For this, different juice models, orange juice/milk beverage, strawberry juice/milk beverage and grape juice, were prepared and spiked individually with AOH and AFB1 at a concentration of 100 µg/L. After HPP and thermal treatments, mycotoxins were extracted from treated samples and controls by dispersive liquid-liquid microextraction (DLLME) and determined by HPLC-MS/MS-IT. The results obtained revealed reduction percentages up to 24% for AFB1 and 37% for AOH. Comparing between different juice models, significant differences were observed for AFB1 residues in orange juice/milk versus strawberry juice/milk beverages after HPP treatment. Moreover, HPP resulted as more effective than thermal treatment, being an effective tool to incorporate to food industry in order to reach mycotoxins reductions.


Assuntos
Aflatoxinas/química , Bebidas/análise , Sucos de Frutas e Vegetais/análise , Frutas/química , Leite/química , Vitis/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Lactonas/química , Microextração em Fase Líquida/métodos , Micotoxinas/química , Espectrometria de Massas em Tandem/métodos
19.
Anal Methods ; 13(30): 3433-3443, 2021 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-34259236

RESUMO

A selective molecularly imprinted polymer (MIP) adsorbent was synthesised and used in a batch micro-solid phase extraction format for isolating aflatoxins (AFB1, and AFB2) from non-dairy beverages before liquid chromatography-tandem mass spectrometry determination. MIP synthesis (precipitation polymerization in 3 : 1 acetonitrile/toluene as a porogen) was performed with 5,7-dimethoxycoumarin (DMC), methacrylic acid (MAA) and divinylbenzene-80 (DVB) as a dummy template, functional monomer and cross-linker, respectively (1 : 4 : 20 molar ratio). 2,2'-Azobisisobutyronitrile (AIBN) was used as a polymerization initiator. The adsorbent MIP (50 mg) was enclosed in a cone-shaped polypropylene membrane (porous membrane protected molecularly imprinted micro-solid phase extraction), and parameters such as sample pH, mechanical (orbital-horizontal) shaking, the extraction time (loading stage), the composition of the eluting solution, and the desorption time were optimised. The highest extraction yields were obtained by using 5 mL of non-dairy beverages (pH adjusted at 6.0), and mechanical shaking (150 rpm) for 15 min. Elution was performed with 5 mL of an acetonitrile/formic acid (97.5 : 2.5) mixture under ultrasound (325 W, 35 kHz) for 15 min. After eluate evaporation to dryness and re-dissolution in 150 µL of the mobile phase, the pre-concentration factor of the method was 33.3, which yields limits of detection within the 0.085-0.207 µg L-1 range. In addition, the current proposal was shown to be an accurate and precise method through relative standard deviation of intraday and inter-day assays below 18% and analytical recoveries in the range of 91-104%. However, the method was found to suffer from matrix effects.


Assuntos
Aflatoxinas , Impressão Molecular , Aflatoxinas/análise , Bebidas , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Polímeros Molecularmente Impressos , Polímeros , Extração em Fase Sólida , Espectrometria de Massas em Tandem
20.
Toxicon ; 200: 55-68, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34228958

RESUMO

Aflatoxins (AFs) are a class of mycotoxins produced by the toxigenic Aspergillus fungi and are common contaminants of foods and feeds. Aflatoxin B1 (AFB1), the most potent aflatoxin, is well characterized to reduce productive performance and mortality in broilers. This exclusive review summarizes the efficacy of various plant products and phytochemicals to counteract AFB1 toxicity in broilers. The biochemical and molecular mode of action of AFB1 to induce liver damage, genotoxicity, immunosuppression and the protective effect of plant products against such mechanisms and their toxic effects are discussed. The link between antioxidant, immunomodulatory and hepatoprotective functions of plant products; oxidative stress and AFB1 macromolecular adducts mediated AFB1 toxicity are covered. Efficacy of Satureja khuzistanica, Zataria multiflora Boiss, Thymus vulgaris, Sauropsus androgynus, Hemidesmus indicus, Leucas aspera, Moringa oleifera, Eclipta alba, Curcuma longa, Silybum marianum, Urtica dioica, and citrus fruit are summarized. The anti-aflatoxic effect of water-soluble substances of wheat, grape seed proanthocyanidin extract and phytochemicals like thymol, carvarol, piperine, transcinnamaldehyde, resveratrol, curcumin, and silymarin are also discussed. Specific plant products and phytochemicals are shown to be effective against AF toxicity in broilers and could represent an important tool to reduce health and economic losses associated with AFB1 exposure.


Assuntos
Aflatoxinas , Galinhas , Aflatoxina B1/toxicidade , Aflatoxinas/toxicidade , Animais , Fígado , Compostos Fitoquímicos/farmacologia
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