Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 910
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
BMC Plant Biol ; 24(1): 394, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741071

RESUMO

Wheat is one of the essential crops for the human and animal nutrition, however, contamination with aflatoxigenic fungi, due to the improper storage conditions and high humidity, was the main global threats. So, preventing the growth of aflatoxigenic fungi in stored wheat grains, by using different essential oils was the main objective of this work. Aspergillus flavus EFBL-MU12 PP087400, EFBL-MU23 PP087401 and EFBL-MU36 PP087403 isolates were the most potent aflatoxins producers inhabiting wheat grains. The effect of storage conditions of wheat grains "humidity, temperature, incubation period, and pH" on growth of A. flavus, was assessed by the response surface methodology using Plackett-Burman design and FCCD. The highest yield of aflatoxins EFBL-MU12 B1 and B2 by A. flavus grown on wheat grains were 145.3 and 7.6 µg/kg, respectively, at incubation temperature 35°C, 16% moisture contents, initial pH 5.0, and incubated for 14 days. The tested oils had a powerful antifungal activity for the growth and aflatoxins production by A. flavus in a concentration-dependent manner. Among these oils, cinnamon oil had the highest fungicidal activity for A. flavus at 0.125%, with about 85-90 % reduction to the aflatoxins B1 and B2, conidial pigmentation and chitin contents on wheat grains. From the SEM analysis, cinnamon oils had the most deleterious effect on A. flavus with morphological aberrations to the conidial heads, vegetative mycelia, alteration in conidiophores identity, hyphae shrank, and winding. To emphasize the effect of the essential oils on the aflatoxins producing potency of A. flavus, the molecular expression of the aflatoxins biosynthetic genes was estimated by RT-qPCR. The molecular expression of nor-1, afLR, pKsA and afLJ genes was suppressed by 94-96%, due to cinnamon oil at 0.062% compared to the control. Conclusively, from the results, cinnamon oils followed by the peppermint oils displayed the most fungicidal activity for the growth and aflatoxins production by A. flavus grown on wheat grains.


Assuntos
Aflatoxinas , Aspergillus flavus , Cinnamomum zeylanicum , Óleos Voláteis , Triticum , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Triticum/microbiologia , Óleos Voláteis/farmacologia , Cinnamomum zeylanicum/química , Antifúngicos/farmacologia , Fungicidas Industriais/farmacologia , Armazenamento de Alimentos , Grão Comestível/microbiologia
2.
BMC Microbiol ; 24(1): 209, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877423

RESUMO

Fungi can spoil the majority of baked products. Spoilage of cake during storage is commonly associated with fungi. Therefore, this study aimed to assess the quality of different types of cakes sold in the market. The most predominant fungal genera in the tested cake samples (14 samples) were Aspergillus spp., and Penicillium spp. On Potato Dextrose Agar (PDA), the medium fungal total count was 43.3 colonies /g. Aspergillus was the most dominant genus and was isolated from six samples of cake. Aspergillus was represented by 3 species namely, A. flavus, A. niger, and A. nidulans, represented by 13.32, 19.99, and 3.33 colonies /g respectively. On Malt Extract Agar (MEA) Medium, the fungal total count was 123.24 colonies / g. Aspergillus was the most dominant isolated genus from 11 samples of cake and was represented by 5 species, namely, A. flavus, A. niger, A. ochraceous, A. terreus, and A. versicolor (26. 65, 63.29, 3.33, 6.66, and 3.33 colonies / g , respectively). Twenty-four isolates (88.88 %) of the total tested twenty-seven filamentous fungi showed positive results for amylase production. Ten isolates (37.03%) of the total tested filamentous fungi showed positive results for lipase production, and finally eleven isolates (40.74 %) of the total fungal isolates showed positive results for protease production. Aflatoxins B1, B2, G1, G2, and ochratoxin A were not detected in fourteen collected samples of cake. In this study, clove oil was the best choice overpeppermint oil and olive oil for preventing mold development when natural agents were compared. It might be due to the presence of a varietyof bioactive chemical compounds in clove oil, whose major bioactive component is eugenol, which acts as an antifungal reagent. Therefore, freshly baked cake should be consumed within afew days to avoid individuals experiencing foodborne illnesses.


Assuntos
Microbiologia de Alimentos , Fungos , Micotoxinas , Fungos/isolamento & purificação , Fungos/classificação , Fungos/enzimologia , Fungos/genética , Micotoxinas/análise , Aspergillus/isolamento & purificação , Aspergillus/enzimologia , Penicillium/isolamento & purificação , Penicillium/enzimologia , Contaminação de Alimentos/análise , Aflatoxinas/análise , Lipase/metabolismo , Amilases/metabolismo , Amilases/análise
3.
Environ Sci Technol ; 58(8): 3580-3594, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38354120

RESUMO

Mycotoxins are a heterogeneous group of toxins produced by fungi that can grow in staple crops (e.g., maize, cereals), resulting in health risks due to widespread exposure from human consumption and inhalation. Dried blood spot (DBS), dried serum spot (DSS), and volumetric tip microsampling (VTS) assays were developed and validated for several important mycotoxins. This review summarizes studies that have developed these assays to monitor mycotoxin exposures in human biological samples and highlights future directions to facilitate minimally invasive sampling techniques as global public health tools. A systematic search of PubMed (MEDLINE), Embase (Elsevier), and CINAHL (EBSCO) was conducted. Key assay performance metrics were extracted to provide a critical review of the available methods. This search identified 11 published reports related to measuring mycotoxins (ochratoxins, aflatoxins, and fumonisins) using DBS/DSS and VTS assays. Multimycotoxin assays adapted for DBS/DSS and VTS have undergone sufficient laboratory validation for applications in large-scale population health and human biomonitoring studies. Future work should expand the number of mycotoxins that can be measured in multimycotoxin assays, continue to improve multimycotoxin assay sensitivities of several biomarkers with low detection rates, and validate multimycotoxin assays across diverse populations with varying exposure levels. Validated low-cost and ultrasensitive minimally invasive sampling methods should be deployed in human biomonitoring and public health surveillance studies to guide policy interventions to reduce inequities in global mycotoxin exposures.


Assuntos
Micotoxinas , Humanos , Saúde Global , Monitoramento Ambiental/métodos
4.
Phytopathology ; : PHYTO06230200KC, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37581424

RESUMO

Aflatoxins are carcinogens produced by the fungi Aspergillus flavus and A. parasiticus that contaminate pistachio crops. International markets reject pistachio when aflatoxins exceed permitted maximum levels. Releasing the atoxigenic strain AF36 of A. flavus is the leading aflatoxin pre-harvest control method. The product AF36 Prevail, sorghum grains coated with AF36 propagules, has been used in California since 2017. However, a high percentage of grains of the Prevail fail to sporulate in orchards. Here, the effect of soil moisture on the percentage of AF36 product grains sporulating (SG) and the quantity of spores per grain using a sporulation index (SI) was determined. Under controlled conditions, SG was higher than 85% when soil moisture was 13% or more, and SI increased with increasing soil moisture from 8.4 to 21%. The highest AF36 sporulation occurred near the micro-sprinklers when the grains were not impacted by the irrigation water drops. Arthropod predation was responsible for lost product grains, which was more pronounced in non-tilled soil than in tilled soil. Dispersal of the AF36 spores decreased markedly with the height and distance from the inoculum source, following a pattern of diffusion equations. However, AF36 spores easily reached canopies of pistachios located 10 m from the inoculum source. Our results indicate that AF36 Prevail should be applied close to the irrigation line in the moist soil area but avoiding the areas where excess irrigation causes water accumulation. The biocontrol of aflatoxins in California's pistachio production areas was optimized by improving the field realization of the biological control agent.

5.
Pestic Biochem Physiol ; 201: 105887, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685218

RESUMO

Aspergillus flavus is a ubiquitous facultative pathogen that routinely infects important crops leading to formation of aflatoxins during crop development and after harvest. Corn and peanuts in warm and/or drought-prone regions are highly susceptible to aflatoxin contamination. Controlling aflatoxin using atoxigenic A. flavus is a widely adopted strategy. However, no A. flavus genotypes are currently approved for use in China. The current study aimed to select atoxigenic A. flavus endemic to Guangxi Zhuang Autonomous Region with potential as active ingredients of aflatoxin biocontrol products. A total of 204 A. flavus isolates from corn, peanuts, and field soil were evaluated for ability to produce the targeted mycotoxins. Overall, 57.3% could not produce aflatoxins while 17.15% were incapable of producing both aflatoxins and CPA. Atoxigenic germplasm endemic to Guangxi was highly diverse, yielding 8 different gene deletion patterns in the aflatoxin and CPA biosynthesis gene clusters ranging from no deletion to deletion of both clusters. Inoculation of corn and peanuts with both an aflatoxin producer and selected atoxigenic genotypes showed significant reduction (74 to 99%) in aflatoxin B1 (AFB1) formation compared with inoculation with the aflatoxin producer alone. Atoxigenic genotypes also efficiently degraded AFB1 (61%). Furthermore, atoxigenic isolates were also highly efficient at reducing aflatoxin concentrations even when present at lower concentrations than aflatoxin producers. The use of multiple atoxigenics was not always as effective as the use of a single atoxigenic. Effective atoxigenic genotypes of A. flavus with known mechanisms of atoxigenicity are demonstrated to be endemic to Southern China. These A. flavus may be utilized as active ingredients of biocontrol products without concern for detrimental impacts that may result from introduction of exotic fungi. Field efficacy trials in the agroecosystems of Southern China are needed to determine the extent to which such products may allow the production of safer food and feed.


Assuntos
Aflatoxinas , Arachis , Aspergillus flavus , Zea mays , Aspergillus flavus/genética , Aspergillus flavus/metabolismo , Arachis/microbiologia , Zea mays/microbiologia , China , Agentes de Controle Biológico , Contaminação de Alimentos/prevenção & controle , Genótipo
6.
Foodborne Pathog Dis ; 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39229759

RESUMO

Because of the medical importance of cumin as well as it being one of the food additives to many Saudi dishes, there was a need to study the fungal load of this type of spice. This study aimed to determine the mycological profile of the retail black and green cumin distributed in different markets at western region, Saudi Arabia, using the dilution plat method on dichloran 18% glycerol (DG18) agar and incubation at 25°C. Using morphological criteria and molecular markers (internal transcribed spacer sequence), 39 species belonging to 18 genera were collected from different black cumin (33 species belonging to 17 genera) and green cumin (25 species belonging to 9 genera). Alternaria alternata, Aspergillus flavus, A. niger, A. ochraceus, Cladosporium cladosporioides, and Stemphylium botryosum were the most prevalent. Black cumin harbors fungal counts reaching 545 colony-forming units (CFU)/g, while green cumin included 500 CFU/g. Also, the natural occurrence of aflatoxins and ochratoxin A was also measured. Seventy-two cumin samples (90% of tested samples) showed toxin contamination. Aflatoxins and ochratoxin A ranged from 9.35 to 3.9 PPB in black cumin samples and from 4.08 to 5.75 PPB in green cumin samples.

7.
Mikrochim Acta ; 191(10): 607, 2024 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-39289224

RESUMO

A functional material was developed with specific recognition properties for aflatoxins for pre-processing enrichment and separation in the detection of aflatoxins in Chinese herbal medicines. In the experiment, ethyl coumarin-3-carboxylate, which has a highly similar structure to the oxonaphthalene o-ketone of aflatoxin, was selected as a pseudo-template, zinc acrylate, neutral red derivative, and methacrylic acid, which have complementary functions, were selected as co-monomers to prepare a pseudo-template multifunctional monomer molecularly imprinted polymer (MIP). The MIP obtained under the optimal preparation conditions has a maximum adsorption capacity of 0.036 mg/mg and an imprinting factor of 3.67. The physical property evaluation of the polymers by Fourier infrared spectrometer, scanning electron microscopy, pore size analyzer, thermogravimetric analyzer, and diffuse reflectance spectroscopy showed that the MIP were successfully prepared and porous spherical-like particles were obtained. The synthesized polymer was used as a solid-phase extraction agent for the separation of aflatoxins from the extract of spina date seed. The linear range of the developed method was 10-1000 ng/mL, the limit of detection was 0.36 ng/mL, the limit of quantification was 1.19 ng/mL, and the recoveries of the extracts at the concentration level of 0.2 µg/mL were in the range 88.0-93.4%, with relative standard deviations (RSDs) of 1.97% (n). The results showed that the preparation of MIPs using ethyl coumarin-3-carboxylate as a template was simple, economical, and convenient. It is expected to become a promising functional material for the enrichment and separation aflatoxins from complex matrices.


Assuntos
Aflatoxinas , Polímeros Molecularmente Impressos , Extração em Fase Sólida , Aflatoxinas/análise , Polímeros Molecularmente Impressos/química , Extração em Fase Sólida/métodos , Adsorção , Impressão Molecular , Limite de Detecção , Acrilatos/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Metacrilatos/química , Polímeros/química
8.
Phytochem Anal ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261748

RESUMO

INTRODUCTION: Aflatoxins, potent carcinogens produced by Aspergillus species, present significant health risks and commonly contaminate herbal products such as Chrysanthemum morifolium. Detecting these toxins in C. morifolium proves challenging due to the complex nature of the herbal matrix and the fluctuating levels of toxins found in different samples. OBJECTIVES: This study aimed to develop and optimize a novel method for the detection of aflatoxins in C. morifolium using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography-fluorescence detection based on quality by design principles. METHODOLOGY: The method involved determining critical method attributes and parameters through the Plackett-Burman design, followed by optimization using the Box-Behnken design. Monte Carlo simulation was employed to establish a design space, which was experimentally verified. Method validation was performed to confirm accuracy, precision, and stability. RESULTS: The developed method exhibited excellent linearity (R2 > 0.9991) for aflatoxins B1, B2, G1, and G2 across a range of concentrations, with recovery rates between 85.52% and 102.01%. The validated method effectively quantified aflatoxins in C. morifolium under different storage conditions, highlighting the impact of temperature and storage time on aflatoxin production. CONCLUSION: This study successfully established a reliable and effective method for the detection of aflatoxins in C. morifolium, highlighting the importance of strict storage conditions to reduce aflatoxin contamination. Using a quality by design framework, the method demonstrated robustness and high analytical performance, making it suitable for routine quality control of herbal products.

9.
Food Control ; 162: 110463, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39092408

RESUMO

Designing and implementing processing procedures for producing safe complementary foods in dynamic and unregulated food systems where common food staples are frequently contaminated with mycotoxins is challenging. This paper presents lessons about minimizing aflatoxins (AF) in groundnut flour and AF and/or fumonisins (FUM) in maize and groundnut pre-blended flour for complementary feeding in the context of a dietary research intervention in rural Tanzania. The flours were processed in collaboration with Halisi Products Limited (Halisi), a medium scale enterprise with experience in milling cereal-based flours in Arusha, Tanzania. Using a hazard analysis critical control point (HACCP) approach for quality assurance, two critical control points (CCPs) for AF in processing the pre-blended flour were identified: 1) screening maize before procurement, and 2) blending during the processing of each constituent flour. Blending of maize flour was also identified as a CCP for FUM. Visual inspection during screening and sorting were identified as important control measures for reducing AF, but these steps did not meet the criteria for a CCP due to lack of objective measurement and verifiable standards for AF. The HACCP approach enabled the production of low AF (<5 µg/kg) and FUM (<2 µg/g) flours with low rejection rates for the final products. The paper presents practical lessons that could be of value to a range of commercial processors in similar low- and middle-income contexts who are keen on improving food quality.

10.
Int J Mol Sci ; 25(14)2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39062915

RESUMO

Cultivated peanut (Arachis hypogaea L.) is a key oil- and protein-providing legume crop of the world. It is full of nutrients, and its nutrient profile is comparable to that of other nuts. Peanut is a unique plant as it showcases a pegging phenomenon, producing flowers above ground, and after fertilization, the developing peg enters the soil and produces seeds underground. This geocarpic nature of peanut exposes its seeds to soil pathogens. Peanut seeds are protected by an inedible pericarp and testa. The pericarp- and testa-specific promoters can be effectively used to improve the seed defense. We identified a pericarp- and testa-abundant expression gene (AhN8DT-2) from available transcriptome expression data, whose tissue-specific expression was further confirmed by the qRT-PCR. The 1827bp promoter sequence was used to construct the expression vector using the pMDC164 vector for further analysis. Quantitative expression of the GUS gene in transgenic Arabidopsis plants showed its high expression in the pericarp. GUS staining showed a deep blue color in the pericarp and testa. Cryostat sectioning of stained Arabidopsis seeds showed that expression is only limited to seed coat (testa), and staining was not present in cotyledons and embryos. GUS staining was not detected in any other tissues, including seedlings, leaves, stems, and roots, except for some staining in flowers. Under different phytohormones, this promoter did not show an increase in expression level. These results indicated that the AhN8DT-2 promoter drives GUS gene expression in a pericarp- and testa-specific manner. The identified promoter can be utilized to drive disease resistance genes, specifically in the pericarp and testa, enhancing peanut seed defense against soil-borne pathogens. This approach has broader implications for improving the resilience of peanut crops and other legumes, contributing to sustainable agricultural practices and food security.


Assuntos
Arachis , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Sementes , Arachis/genética , Arachis/metabolismo , Sementes/genética , Clonagem Molecular/métodos , Plantas Geneticamente Modificadas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Arabidopsis/genética
11.
Molecules ; 29(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38792140

RESUMO

Aflatoxins (AFs) including AFB1, AFB2, AFG1 and AFG2 are widely found in agriculture products, and AFB1 is considered one of the most toxic and harmful mycotoxins. Herein, a highly sensitive (at the pg mL-1 level) and group-specific enzyme-linked immunosorbent assay (ELISA) for the detection of AFB1 in agricultural and aquiculture products was developed. The AFB1 derivative containing a carboxylic group was synthesized and covalently linked to bovine serum albumin (BSA). The AFB1-BSA conjugate was used as an immunogen to immunize mice. A high-quality monoclonal antibody (mAb) against AFB1 was produced by hybridoma technology, and the mAb-based ELISA for AFB1 was established. IC50 and limit of detection (LOD) of the ELISA for AFB1 were 90 pg mL-1 and 18 pg mL-1, respectively. The cross-reactivities (CRs) of the assay with AFB2, AFG1, and AFG2 were 23.6%, 42.5%, and 1.9%, respectively, revealing some degree of group specificity. Corn flour, wheat flour, and crab roe samples spiked with different contents of AFB1 were subjected to ELISA procedures. The recoveries and relative standard deviation (RSD) of the ELISA for AFB1 in spiked samples were 78.3-116.6% and 1.49-13.21% (n = 3), respectively. Wheat flour samples spiked with the mixed AF (AFB1, AFB2, AFG1, AFG2) standard solution were measured by ELISA and LC-MS/MS simultaneously. It was demonstrated that the proposed ELISA can be used as a screening method for evaluation of AFs (AFB1, AFB2, AFG1, AFG2) in wheat flour samples.


Assuntos
Aflatoxina B1 , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos , Animais , Camundongos , Aflatoxina B1/análise , Aflatoxina B1/imunologia , Agricultura , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/química , Ensaio de Imunoadsorção Enzimática/métodos , Farinha/análise , Contaminação de Alimentos/análise , Limite de Detecção , Soroalbumina Bovina/química , Zea mays/química , Zea mays/microbiologia
12.
Int J Environ Health Res ; : 1-19, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842007

RESUMO

Mycotoxins have been identified as considerable contaminants in beer. The current investigation's concentration and prevalence of aflatoxins (AFs) in beer were meta-analyzed. The health risk of consumers was estimated through MOEs in the Monte Carlo simulation (MCS) model. The rank order of AFs in beer based on pooled prevalence was AFB1 (26.00%) > AFG1 (14.93%) > AFB2 (7.69%) > AFG2 (7.52%), In addition, the rank order of AFs in beer based on their pooled concentration was AFG1 (0.505 µg/l) > AFB1 (0.469 µg/l) > AFB2 (0.134 µg/l) > AFG2 (0.071 µg/l). The prevalence and concentration of AFs in beer in Malawi were higher than in other countries. The health risk assessment shows consumers in all countries, especially Malawi, Brazil, and Cameroon, are exposed to unacceptably health risks (MOEs <10,000). It is recommended to monitor levels of AFs in beer efficiently and implement control plans in order to decrease health risk of exposed population.

13.
J Sci Food Agric ; 104(12): 7441-7453, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38738519

RESUMO

BACKGROUND: This study aims to explore both the toxic effects of aflatoxins (AFs) and the protective effects of degrading enzymes (DE) on broilers exposed to AFs. RESULTS: The findings reveal that a diet contaminated with 69.15 µg kg-1 of aflatoxin B1 had significant adverse effects on broilers. Specifically, it led to a reduction in average daily gain, dressed yield percentage, half-eviscerated yield with giblet yield percentage, eviscerated yield percentage, as well as serum superoxide dismutase (SOD), glutathione peroxidase activity and liver SOD activity (P < 0.05). Conversely, the diet increased the feed conversion ratio, liver index, serum glutamic oxaloacetic transaminase levels and malondialdehyde levels in both serum and liver (P < 0.05). Additionally, AFs disrupted the intestinal microflora significantly (P < 0.05), altering the relative abundance of Enterococcus, Lactobacillus and Escherichia in broiler jejunum. The addition of DE to AF-contaminated feed mitigated these negative effects and reduced the residues of aflatoxin B1, aflatoxin B2 and aflatoxin M1 in the liver and duodenum (P < 0.05). We also observed that broilers fed the diet pelleted at 80 °C exhibited improved dressing percentage and water holding capacity compared to those on the 75 °C diet. CONCLUSION: In summary, DE serves as an effective feed additive for mitigating AF contamination in poultry production. © 2024 Society of Chemical Industry.


Assuntos
Aflatoxinas , Ração Animal , Bactérias , Galinhas , Contaminação de Alimentos , Microbioma Gastrointestinal , Fígado , Animais , Galinhas/metabolismo , Galinhas/crescimento & desenvolvimento , Microbioma Gastrointestinal/efeitos dos fármacos , Aflatoxinas/metabolismo , Aflatoxinas/toxicidade , Ração Animal/análise , Fígado/metabolismo , Contaminação de Alimentos/análise , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , Bactérias/enzimologia , Dieta/veterinária , Masculino , Superóxido Dismutase/metabolismo , Glutationa Peroxidase/metabolismo , Aflatoxina B1/metabolismo , Aflatoxina B1/toxicidade , Malondialdeído/metabolismo
14.
Compr Rev Food Sci Food Saf ; 23(3): e13363, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38720588

RESUMO

There is still considerable controversy about the relative risk of mycotoxin exposure associated with the consumption of organic and conventional cereals. Using validated protocols, we carried out a systematic literature review and meta-analyses of data on the incidence and concentrations of mycotoxins produced by Fusarium, Claviceps, Penicillium, and Aspergillus species in organic and conventional cereal grains/products. The standard weighted meta-analysis of concentration data detected a significant effect of production system (organic vs. conventional) only for the Fusarium mycotoxins deoxynivalenol, with concentrations ∼50% higher in conventional than organic cereal grains/products (p < 0.0001). Weighted meta-analyses of incidence data and unweighted meta-analyses of concentration data also detected small, but significant effects of production system on the incidence and/or concentrations of T-2/HT-2 toxins, zearalenone, enniatin, beauvericin, ochratoxin A (OTA), and aflatoxins. Multilevel meta-analyses identified climatic conditions, cereal species, study type, and analytical methods used as important confounding factors for the effects of production system. Overall, results from this study suggest that (i) Fusarium mycotoxin contamination decreased between the 1990s and 2020, (ii) contamination levels are similar in organic and conventional cereals used for human consumption, and (iii) maintaining OTA concentrations below the maximum contamination levels (3.0 µg/kg) set by the EU remains a major challenge.


Assuntos
Grão Comestível , Contaminação de Alimentos , Micotoxinas , Grão Comestível/química , Grão Comestível/microbiologia , Micotoxinas/análise , Contaminação de Alimentos/análise , Fusarium/química , Alimentos Orgânicos/análise , Alimentos Orgânicos/microbiologia
15.
Indian J Microbiol ; 64(2): 500-510, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39010989

RESUMO

Sugarcane is one of the most important crops in the world. It is also considered the most popular fresh juice in Egypt. The sugar content of the sugarcane stem represents the main source of fungal growth. This study aimed to investigate the natural co-occurrence of fungi in sugarcane plants and juice, test of aflatoxins production by aflatoxigenic fungi, and improve the quality of sugarcane juice. The obtained results indicated a notable decrease in all physical parameters of the naturally infected sugarcane plants. Isolation of fungi from sugarcane plant and juice from three localities revealed that the highest mean fungal count was recorded in sugarcane rootlets (173.55 cfu/cm), followed by sugarcane stem (94.88 cfu/cm), while sugarcane juice had the least mean fungal count (24.33 cfu/mL). The frequency of the isolated fungi associated with sugarcane plant yielded 781 fungal isolates for rootlets, 427 fungal isolates for stems, and 219 fungal isolates for juice. Four isolates of Aspergillus parasiticus were aflatoxins producers. Higher aflatoxin quantity (1434.92 ng/mL) was produced by A. parasiticus (isolate No. 21) from sugarcane stem, while A. parasiticus (isolate No. 5) from sugarcane juice was less aflatoxins producer (276.95 ng/mL). On the other hand, lemon juice showed a significant reduction effect on the fungal count of peeled and non-peeled sugarcane juice. In which the highest reduction percent of the fungal count was recorded with 20% conc. of lemon on peeled sugarcane juice (36.04%).The obtained results concluded that lemon juice was found to decrease the fungal contaminants and improve the quality of sugarcane juice.

16.
Anal Bioanal Chem ; 415(23): 5681-5694, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37507464

RESUMO

Aflatoxins (AFs), an important category of pollutants, are formed in many foods and adversely affect human health. Therefore, their determination is critical to ensuring human food health. An efficient dispersive solid-phase microextraction technique was developed as a simple and straightforward sample preparation technique for determination of four aflatoxins using a high-performance liquid chromatography (HPLC) fluorescence detector. A novel efficient, green sorbent for extracting AFs was synthesized based on hydrothermal and chemical strategies. The amounts of three sorbent components were optimized using a mixture design (simplex lattice design), including 14 experiments. The optimal amount of amino-bimetallic Fe/Ni-MIL-53 nanospheres, chitosan, and magnetic Fe3O4 nanoparticles as sorbent components was 0.87, 0.67, and 0.47 g, respectively. Also, various factors affecting the process of AF determination were studied and optimized in two successive experimental designs, including the definitive screening design and the Box-Behnken design. Under optimal conditions, the linear ranges for measuring aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 were 0.05-82.6, 0.07-86.4, 0.08-85.7, and 0.07-89.5 ng mL-1, respectively. The relative standard deviations under inter-day and intra-day conditions for measuring AFs at three analyte concentrations were determined in triplicate analysis and were in the ranges of 3.7-4.6% and 4.9-6.1% for water sample analysis, respectively. The qualitative detection limits for determining AFs were between 0.01 and 0.05 ng mL-1. The pre-concentration factor of the method for measuring AFs ranged from 739.7 to 802.1. The proposed method was used for determining AFs in several real samples, including herbal distillate, black tea, corn, and real water samples. The relative recovery and standard deviation were 87.8-97.8% and 4.10-6.82%, respectively.

17.
J Appl Microbiol ; 134(5)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37073118

RESUMO

AIMS: Elucidating the identity of an isolate of Aspergillus sp. obtained during searches for anti-coffee leaf rust (CLR) biocontrol agents, from healthy coffee berry samples, preliminarily verify whether it is an aflatoxin-producer, confirm its ability to grow as an endophyte in healthy coffee tissues and assess its biocontrol potential against CLR. METHODS AND RESULTS: One, among hundreds of fungal isolates fungus were obtained from healthy coffee tissues belonged to Aspergillus (isolate COAD 3307). A combination of morphology features and molecular analyses; including four regions-internal transcribed spacer, second-largest subunit of RNA polymerase (RPB2), ß-tubulin (BenA) and calmodulin (CAL)-identified COAD 3307 as Aspergillus flavus. Inoculations of healthy Coffea arabica with COAD 3307 confirmed its establishment as an endophyte in leaves, stems, and roots. Treatment of C. arabica plants by combinated applications of COAD 3307 on aerial parts and in the soil, significantly (P > .0001) reduced CLR severity as compared to controls. Thin-layer chromatography indicated that COAD 3307 is not an aflatoxin-producing isolate. In order to confirm this result, the extract was injected into high-performance liquid chromatography system equipped with a fluorescence detector, and no evidence of aflatoxin was found. CONCLUSIONS: COAD 3307 is an endophytic isolate of A. flavus-a species that has never been previously recorded as an endophyte of Coffea spp. It is a non-aflatoxin producing strain that has an anti-CLR effect and merits further evaluation as a biocontrol agent.


Assuntos
Aflatoxinas , Basidiomycota , Coffea , Aspergillus flavus , Camarões , Basidiomycota/genética , Aspergillus , Doenças das Plantas/microbiologia , Coffea/microbiologia
18.
Regul Toxicol Pharmacol ; 145: 105503, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37778435

RESUMO

The present study aims to investigate the presence of Aflatoxins (AF) in 180 samples dried fruits and Ochratoxin A (OTA) in 210 samples dried fruits and grape juices collected in Morocco. Mycotoxins were analyzed by high performance liquid chromatography (HPLC) coupled to fluorescence detection and immunoaffinity columns (IAC) cleanup. Contamination levels were compared with the maximum regulatory limits (MRL) recently adopted in the country, and mycotoxin exposure of adult consumers was assessed. Results showed that 13.8% of samples were contaminated with AF, with incidences of 23.3, 23.3, 20, 13.8, and 3.3%, in raisins, figs, nuts, peanuts and pistachio, respectively. There were 12 samples (6.6%) that exceeded the MRL of 2-12 ng/g set for aflatoxin B1 (AFB1). While OTA was detected in 17.1% of samples, with incidences of 3.3, 3.3, 30, 30, and 53.3% in walnuts, pistachios, peanuts, raisins and figs, respectively, and a maximum value of 99.1 in dried raisins, that exceeded the MRL (10 ng/g) set for OTA. The co-occurrence of OTA and AF was observed in 4.7% of total samples. Dietary intake showed that the OTA exposure level was lower than safety guidelines set by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) at 100 ng/kg b.w./week.


Assuntos
Aflatoxinas , Micotoxinas , Vitis , Aflatoxinas/análise , Frutas/química , Marrocos , Contaminação de Alimentos/análise , Micotoxinas/análise , Cromatografia Líquida de Alta Pressão , Arachis
19.
Lett Appl Microbiol ; 76(12)2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38111225

RESUMO

Populations of ochratoxin-producing Aspergillus section Circumdati species and aflatoxin-producing Aspergillus section Flavi species frequently coexist in soil and are the main sources of mycotoxin contamination of tree nuts. Identification of mycotoxigenic Aspergillus species in these sections is difficult using traditional isolation and culture methods. We developed a multiplex digital PCR (dPCR) assay to detect and quantify Aspergillus ochraceus, Aspergillus westerdijkiae, and Aspergillus steynii (section Circumdati), as well as Aspergillus flavus and Aspergillus parasiticus (section Flavi), in environmental samples based on species-specific calmodulin gene sequences. Relative quantification of each species by dPCR of mixed-species templates correlated with corresponding DNA input ratios. Target species could be detected in soil inoculated with conidia from each species. Non-target species of sections Circumdati, Flavi, and Nigri were generally not detectable using this dPCR method. Detected non-target species (Aspergillus fresenii, Aspergillus melleus, Aspergillus sclerotiorum, and Aspergillus subramanianii) were discernible from A. ochraceus in dual-template dPCR reactions based on differential fluorescence intensity.


Assuntos
Aflatoxinas , Micotoxinas , Aspergillus/genética , Aspergillus flavus/genética , Reação em Cadeia da Polimerase Multiplex , Solo
20.
J Dairy Sci ; 106(8): 5468-5473, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37296052

RESUMO

The objective of the study was to identify the presence of toxigenic fungi Aspergillus spp. and Fusarium spp. in domestic flies collected from dairy farms. We selected 10 dairy farms distributed in the central valley of the state of Aguascalientes, México. The flies were trapped using entomological traps with an olfactory attractant in 7 sites of the farm (silo-cutting surface, feed store, milking parlor, 3 feeders, and the rearing room). The fungi were cultivated in Sabouraud agar through direct sowing by serial dilutions to obtain the isolates, and a taxonomical identification was carried out under the microscope. The aflatoxins and zearalenone production capacity of the pure isolates were quantified using the ELISA test. The flies were present in all of the capture sites (45.3 flies, 567 mg, trap per day). We obtained 50 isolates of Aspergillus spp. genus, 12 of which produced aflatoxins (327 ± 143 µg/kg), whereas from 56 of the Fusarium spp. isolates, 10 produced large quantities of zearalenone (3,132 ± 665 µg/kg). These results suggest that the presence of domestic flies on dairy farms can constitute a source of dissemination for toxigenic fungi that can eventually contaminate grains and forage that are part of the daily cattle diet.


Assuntos
Aflatoxinas , Fusarium , Moscas Domésticas , Muscidae , Zearalenona , Animais , Bovinos , Moscas Domésticas/microbiologia , Fazendas , Aspergillus , Fungos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA