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1.
Environ Monit Assess ; 193(4): 214, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33759035

RESUMO

There is a close relationship between human health and the quality of the ration used by domestic animals. Also, molds, like genus of Aspergillus, infect animal and human food products with dangerous toxic substances, i.e., aflatoxins that are causing primary and secondary mycotoxicosis in animals and human. The aim of this study was to compare fungal species that contaminated and produced aflatoxin in livestock and poultry feed in Gonabad that is a semi-arid city in northeast of Iran. Sampling was randomly performed three times from two livestock feed mills and two poultry feed mills during summer and autumn. Samples were cultured in two forms of solid and suspension in Sabouraud dextrose agar with chloramphenicol medium (SC) for 5 days in 28 °C. Microscopic diagnostic test and also molecular diagnostic test were used to determine fungal species in culture based on ß-tubulin gene sequencing. A total of 27.25% and 31.7% of two livestock feed and two poultry feed samples were contaminated with Aspergillus, respectively. Aspergillus flavus (n = 4), Aspergillus Fumigatus (n = 2), Aspergillus versicolor (n = 2), Aspergillus niger (n = 2), Aspergillus parasiticus (n = 1), Aspergillus ochraceus (n = 1), and Aspergillus terreus (n = 1) were detected by molecular PCR test. The rate of contamination to genus of Aspergillus in autumn was higher than summer (P value = 0.008). Poultry feed sample showed more contamination to Aspergillus species compared with livestock feed.


Assuntos
Aflatoxinas , Testes Diagnósticos de Rotina , Aflatoxinas/análise , Ração Animal/análise , Animais , Aspergillus , Aspergillus flavus , Monitoramento Ambiental , Fungos , Humanos , Irã (Geográfico)
2.
Environ Pollut ; 277: 116715, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33652183

RESUMO

Herbs and spices are food crops susceptible to contamination by toxigenic fungi. Ozone, as a decontamination approach in the industry, has attractive benefits over traditional food preservation practices. A contribution to the studying of ozone as an antifungal and anti-mycotoxigenic agent in herbs and spices storage processes is achieved in this research. Nine powdered sun-dried herbs and spices were analyzed for their fungal contamination. The results indicate that licorice root and peppermint leaves were found to have the highest population of fungi while black cumin and fennel record the lowest population. The most dominant fungal genera are Aspergillus, Penicillium, Fusarium, and Rhizopus. Ozone treatment was performed at a concentration of 3 ppm applied for exposure times of 0, 30, 90, 150, 210, and 280 min. After 280 min of exposure to ozone, the reduction of fungal count ranged from 96.39 to 98.26%. The maximum reduction in spore production was achieved in the case of A. humicola and Trichderma viride exposed for 210 min ozone gas. There was a remarkable reduction in the production of the total mycotoxin, reaching 24.15% in aflatoxins for the 150 min-treated inoculum in the case of A. flavus. The total volume of essential oil of chamomile and peppermint was reduced by 57.14 and 26.67%, respectively, when exposed to 3 ppm. For 280 min. In conclusion, fumigation with ozone gas can be used as a suitable method for achieving sanitation and decreasing microbial load in herbs and spices. Still, it is crucial to provide precautions on ozone's effect on major active constituents before recommending this method for industrial application.


Assuntos
Aflatoxinas , Micotoxinas , Ozônio , Aflatoxinas/análise , Contaminação de Alimentos/análise , Especiarias/análise
3.
Food Chem ; 354: 129497, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33752112

RESUMO

Aflatoxin B1 is the potential chemical contaminant of most concern during the production and storage of fermented tea. In this work, a simple, fast, sensitive, accurate, and inexpensive method has been developed and validated for the simultaneous detection of four aflatoxins in fermented tea based on a modified sample pretreatment method and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Aflatoxins were extracted using acetonitrile and purified using mixed fillers (carboxyl multiwalled carbon nanotubes, hydrophilic-lipophilic balance, silica gel). Under optimum LC-MS conditions, the limits of quantification (LOQs) were 0.02-0.5 µg·kg-1. Recoveries from aflatoxins-fortified tea samples (1-12 µg·kg-1) were in the range of 78.94-105.23% with relative standard deviations (RSDs) less than 18.20%. The proposed method was applied successfully to determine aflatoxin levels in fermented tea samples.


Assuntos
Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão/métodos , Chás de Ervas/análise , Aflatoxinas/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Nanotubos de Carbono/química , Reprodutibilidade dos Testes , Sílica Gel/química , Espectrometria de Massas em Tandem
4.
Food Res Int ; 140: 109878, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33648196

RESUMO

Aflatoxins are toxic secondary metabolites mainly produced by Aspergillus fungi, posing high carcinogenic potency in humans and animals. Dietary exposure to aflatoxins is a global problem in both developed and developing countries especially where there is poor regulation of their levels in food and feed. Thus, academics have been striving over the decades to develop effective strategies for degrading aflatoxins in food and feed. These strategies are technologically diverse and based on physical, chemical, or biological principles. This review summarizes the recent progress on novel aflatoxin degradation strategies including irradiation, cold plasma, ozone, electrolyzed oxidizing water, organic acids, natural plant extracts, microorganisms and enzymes. A clear understanding of the detoxification efficiency, mechanism of action, degradation products, application potential and current limitations of these methods is presented. In addition, the development and future perspective of nanozymes in aflatoxins degradation are introduced.


Assuntos
Aflatoxinas , Aflatoxinas/análise , Animais , Aspergillus , Alimentos , Contaminação de Alimentos/análise , Humanos
5.
Food Res Int ; 140: 109899, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33648201

RESUMO

Peanuts in China are heavily contaminated with aflatoxin, which pose a threaten to human health. To compare the dietary exposure risk of aflatoxins (AFT) in peanuts and peanut oil in different areas of China, the spatial distribution of AFT contamination levels in peanuts and peanut oil from different areas was analyzed. The dietary exposure was calculated by simple distributed risk assessment method before characterizing the health risk using both the margin of exposure (MOE) approach proposed by the European Food Safety Authority (EFSA) and the quantitative liver cancer risk approach proposed by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO) Expert Committee on Food Additives (JECFA). The results showed that the AFT content in peanuts and peanut oil was high with agglomeration in several provinces of East and South China under a subtropical temperate monsoon climate, and the AFT contamination in peanut oil was more substantial than peanuts. On average, the estimated dietary exposure to AFT from the total of peanuts and peanut oil for Chinese general population ranged from 1.776 to 1.940 ng/kg bw/day (LB-UB), from which the MOE values of 88-96 (UB-LB) and liver cancer risk of 0.055-0.060 cases/100,000 persons/year (LB-UB) were calculated. As for different areas in China, the mean AFT exposure ranged between 0.000 and 17.270 ng/kg bw/day. Moreover, the corresponding health risk was estimated at 10-868759 MOE values and 0.000-0.851 liver cancer cases/100,000 persons/year. Guangdong, Fujian and Jiangxi provinces were at a higher risk rank. The liver cancer risk of AFT exposure from peanuts and peanut oil was far below all-cause liver cancer incidence (18.0 cases/100,000 persons/year) in China, but several areas with relatively high risk should be of concern. Compared with other age groups, children aged 2-6 years should be paid more attention because they have the highest AFT exposure level.


Assuntos
Aflatoxinas , Aflatoxina B1/análise , Aflatoxinas/análise , Arachis , Criança , Pré-Escolar , China/epidemiologia , Exposição Dietética , Contaminação de Alimentos/análise , Humanos , Óleo de Amendoim , Análise Espacial
6.
Toxicon ; 195: 7-16, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33610638

RESUMO

Aflatoxins are carcinogenic compounds produced by certain Aspergillus spp and naturally contaminate poultry rations. Exposure to low levels of Aflatoxin B1 (AFB1) in poultry feeds is the second most threatening issue facing the poultry industry in Egypt; it can cause a reduction in growth, egg production, and compromised immune functions, resulting in significant economic loss. Hence, a safe, effective and eco-friendly detoxification method is strongly required. Biological decontamination is a promising approach to reduce aflatoxin levels within threshold limits. This study explores the biodegradation capacity of bacteria isolated from the moldy feed, soil and poultry feces in various poultry farms against AFB1 (100 ppb), G1 (100 ppb), B2 (30 ppb), G2 (30 ppb). Sixty-five bacterial isolates were initially screened using coumarin media with a concentration of (0.01%-0.5%) coumarin. Only one soil isolate (SZ1) grew at the highest concentration (0.5%). Coumarin and Aflatoxin degradation rates of ten promising isolates were measured using spectrophotometry and HPLC. Six isolates reduced AFG1 by more than 90% in the liquid medium, five reduced AFB2 while only four did the same with AFB1& AFG2. Impressively, isolate SZ1 (identified as Pseudomonas fluorescens) exhibited the best degradation capacity to both coumarin and aflatoxin with 100% degradation of AFG1 and 99% degradation of AFB1, AFB2 and AFG2. Biochemical and molecular identification of the ten isolates revealed that they belong to four genera; Bacillus (6), Pseudomonas (2), Enterococcus (1) and Stenotrophomonas (1). Factors affecting Pseudomonas fluorescens SZ1 degradation activity was further investigated. Optimum temperature, time and pH for maximum aflatoxin degradation were at 37 °C, 72 h and 7, respectively. Treatment with proteinase K reduced the degradation activity of G1 (31% ± 1.438), B1 (42% ± 1.438), G2 (19% ± 1.097), and B2 (25% ± 1.732), suggesting that the effective component in aflatoxin degradation may be protein in nature. Our study suggests the biocontrol potential of several different species isolated from poultry farms; B. haynesii, B. licheniformis, B. tequilensis, B. subtilis, B. amyloliquefaciens, Pseudomonas fluorescens, Enterococcus casseliflavus, and Stenotrophomonas maltophilia. The results proposed Pseudomonas fluorescens SZ1 as an excellent candidate for bioremediation and decontamination of aflatoxin in feed matrices. To the best of our knowledge, this is the first report identifying B. haynesii, Enterococcus casseliflavus, B. tequilensis and B. amyloliquefaciens with aflatoxin degradation activity.


Assuntos
Aflatoxinas/metabolismo , Biodegradação Ambiental , Aflatoxina B1/análise , Aflatoxinas/análise , Animais , Egito , Enterococcus , Fazendas , Aves Domésticas
7.
Nutr. hosp ; 38(1): 146-151, ene.-feb. 2021. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-198851

RESUMO

ANTECEDENTES Y OBJETIVO: las aflatoxinas son metabolitos secundarios producidos por hongos de los géneros Aspergillus y Penicillium. Estos hongos contaminan los cereales y varios otros tipos de alimentos. Los efectos fisiopatológicos de las aflatoxinas en los seres humanos incluyen el cáncer de hígado, la cirrosis y la acumulación en los tejidos humanos. El objetivo del estudio fue cuantificar las aflatoxinas cancerígenas en alimentos no procesados vendidos en los mercados de alimentos de 13 distritos de la ciudad de Lima, Perú, y discutir el efecto sobre la salud pública. MATERIALES Y MÉTODOS: se realizó un ensayo inmunoenzimático -utilizando el kit Veratox(R) para la aflatoxina total- a fin de detectar aflatoxinas en los alimentos de consumo humano, mencionándose además la implicación de los hallazgos para la salud pública. RESULTADOS: los alimentos más contaminados que se encontraron fueron el cacahuete o maní (Arachis hypogaea) (149,7 ppb) del mercado Limoncillo del distrito de Rímac y el ají panca o chile rojo peruano (Capsicum chinense) (56,4 ppb) del mercado central del distrito de Comas. El cacahuete se puede consumir crudo en pastas o cremas y el ají panca también se consume a veces crudo, siempre de forma sostenida en el tiempo al formar parte de la gastronomía típica de Perú. CONCLUSIONES: se demuestra un alto riesgo para la salud pública debido al vínculo entre las aflatoxinas de estos alimentos y el cáncer de hígado, principalmente, en una ciudad donde el cáncer hepático y el gástrico son prevalentes


INTRODUCTION AND OBJECTIVES: aflatoxins are secondary metabolites produced by fungi of the Aspergillus and Penicillium geni. These fungi contaminate cereals and several other types of food. The pathophysiologic effects of aflatoxins in humans include liver cancer, cirrhosis, and accumulation in human tissues. The study aimed to quantify carcinogenic aflatoxins in unprocessed food sold in the foodstuff markets of 13 districts of the city of Lima, Perú, and to discuss their effects for public health. METHODS: in order to so, we performed an immunoenzymatic assay using a Veratox(R) kit for total aflatoxin to detect aflatoxins in food for human consumption, and the implications of our findings for public health. RESULTS: the most contaminated foods we found included peanuts (Arachis hypogaea) (149.7 ppb) from the Limoncillo market at the Rimac district, and "ají panca" or Peruvian red chili pepper (Capsicum chinense) (56.4 ppb) from the central market at the Comas district. Peanuts may be eaten raw in pasta or creams, and Capsicum chinense is also eaten sometimes raw, always in a sustained manner over time as part of typical Peruvian cuisine. CONCLUSIONS: we demonstrated a high risk to public health due to the link between aflatoxins in these foods and mainly liver cancer, in a city where the hepatic cancer and gastric cancer are prevalent


Assuntos
Humanos , Aflatoxinas/efeitos adversos , Aflatoxinas/análise , 24457/normas , Microbiologia de Alimentos , Peru , Arachis , Capsicum , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Neoplasias Gástricas/epidemiologia , Estudos Transversais , Estudos Prospectivos
8.
Int J Food Microbiol ; 337: 108940, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33232888

RESUMO

Fungal contamination and mycotoxin accumulation in agricultural products are influenced markedly by processing and storage conditions. This study aimed at determining the growth of Aspergillus flavus and aflatoxin production in Bambara groundnut flour processed by milling, lactic acid bacteria (Lactobacillus plantarum) fermentation or roasting at 140 °C for 20 min and stored for up to 10 weeks at 25 ± 2 °C and 75 ± 2% relative humidity. It also studied the behaviour of A. flavus in maize-bambara composite flour. Processed and irradiated flour samples were inoculated with 2 × 107 spores/ml of A. flavus and stored. Samples were withdrawn weekly and analyzed for viable populations of A. flavus, concentrations of AFB1, AFB2, AFG1 and AFG2 using HPLC-Fluorescence detection method, and changes in water activity values. The population of A. flavus significantly (p ≤ 0.05) decreased in roasted Bambara groundnut flour from 7.18 to 2.00 Log10 CFU/g over the storage period, and in fermented Bambara groundnut flour from 6.72 to 2.67 Log10 CFU/g after 7 weeks of storage and beyond was not detected. Significant (p ≤ 0.05) decrease in the concentration of AFB1 from 0.36 to 0.26 µg/kg and AFG1 from 0.15 to 0.07 µg/kg was also recorded in roasted Bambara groundnut flour over the storage period. Conversely, AFB1 concentration in the composite flour significantly (p ≤ 0.05) increased from 1.17 to 2.05 µg/kg over the storage period. Lactic acid bacteria fermentation, roasting and compositing markedly influenced the growth of A. flavus and aflatoxin production in Bambara groundnut and maize flours during storage.


Assuntos
Aspergillus flavus/crescimento & desenvolvimento , Manipulação de Alimentos , Microbiologia de Alimentos , Vigna/microbiologia , Aflatoxinas/análise , Aflatoxinas/metabolismo , Culinária , Fermentação , Farinha/microbiologia , Armazenamento de Alimentos , Zea mays/microbiologia
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 246: 118999, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33038860

RESUMO

Nanomaterials-based colorimetric immunoassays showed increasing attention for monitoring different biomarkers because of their unique optical and electrical features. Here, a highly sensitive and selective optical sensor was described for the determination of different aflatoxins (AFs). Mesoporous silica nanoparticles (m-SNPs) with an average particle size of 40 nm were prepared by the sol-gel method and then decorated with gold nanoparticles (AuNPs). The Au NPs@m-SiNPs nanocomposite with an average particle size of 66 nm was modified with AFs antibodies. The assay includes the following steps: the Au NPs@m-SiNPs nanocomposite was immersed with AFs antibodies, and then the AFs-Ab/Au NPs@m-SiNPs was used as a probe for AFs detection. The interaction between the AFs-Ab/Au NPs@m-SiNPs and the AFs has resulted in a change in its color from pink to violet. Measurements are performed by absorptiometry at a wavelength of 425 nm. The immunoassay works in the concentration range from 1 ng·mL-1 to 75 ng·mL-1 AFB1 and has a limit of detection 0.16 ng·mL-1 (at S/N = 3). The assay was applied to the determination of AFs in different food samples spiked with AFS. Finally, the assay was used to detect AFs in a real sample, and the LC-MS technique was used to verify the results.


Assuntos
Aflatoxinas , Nanopartículas Metálicas , Aflatoxinas/análise , Colorimetria , Ouro , Imunoensaio , Dióxido de Silício
10.
Environ Sci Pollut Res Int ; 27(33): 42064-42071, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32705556

RESUMO

Storage of wheat in conventional packaging materials is not safe as seeds gain moisture from surrounding air of high relative humidity which promotes growth of fungal and insect pests and loss of quality during storage. Implementing the dry chain, initial drying to low moisture content followed by storage in hermetic bags to maintain low moisture may prevent these losses without using fumigants or chemicals. Different levels of initial moisture contents (SMC), i.e., 8, 10, 12, and 14% and packaging materials, including hermetic super bags along with paper, woven polypropylene (PP), jute, and cloth bags were used as two factors for this experiment. After 4 months of storage, small variation in SMC of seed was observed in super bags while SMC increased significantly in conventional packaging materials. Higher storage losses (≈9%), grain quality losses and aflatoxin B1, B2, G1, and G2 contamination (1-2 ppb) in conventional packaging materials were linked to high seed moisture contents. Storage in hermetic bags at 8 and 10% SMC ideally preserved seed quality. In conclusion, hermetic storage of wheat at low seed moisture maintains a dry chain and prevents aflatoxin contamination and grain quality losses and offers an organic approach to avoid contamination of food grains.


Assuntos
Aflatoxinas , Praguicidas , Aflatoxinas/análise , Grão Comestível/química , Sementes/química , Triticum
11.
Arch Microbiol ; 202(9): 2379-2390, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32588083

RESUMO

In the aquaculture industry, the selection and quality of feed are highly relevant because their integrity and management have an impact on the health and development of organisms. In general, feeds contamination depends on storage conditions and formulation. Furthermore, it has been recognized that filamentous fungi are among the most important contaminating agent in formulated feeds. Therefore, the purpose of this research was to identify saprophytic fungi capable of proliferating in commercial feeds, as well as determining their prevalence, extracellular enzymes profile, ability to assimilate carbon sources, and finally their ability to produce aflatoxins. In order to do that, twenty-two fungi were isolated from commercial fish feeds. After, the species Aspergillus chevalieri, A. cristatus, A. sydowii, A. versicolor, A. flavus, A. creber, and Lichtheimia ramosa were identified. These fungi were able to produce extracellular enzymes, such as phosphatases, esterases, proteases, ß-glucosidase, and N-acetyl-ß-glucosaminidase. The isolated fungi showed no selective behavior in the assimilation of the different carbon sources, showing a strong metabolic diversity. Prevalence percentages above 85% were recorded. Among all fungi studied, A. flavus M3-C1 had the highest production of aflatoxins when this strain was inoculated directly in the feeds (295 ppb). The aflatoxin production by this strain under the experimental setting is above the permitted levels, and it has been established that high levels of aflatoxins in feeds can cause alterations in fish growth as well as the development of cancerous tumors in the liver, in addition to enhancing mortality.


Assuntos
Aflatoxinas/análise , Ração Animal/microbiologia , Fungos/classificação , Fungos/crescimento & desenvolvimento , Animais , Organismos Aquáticos , Proliferação de Células , Peixes , Fungos/isolamento & purificação , Fungos/patogenicidade
12.
Sci Total Environ ; 731: 138851, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32408204

RESUMO

Provision of supplementary food for garden birds is practiced on a large scale in multiple countries. While this resource has benefits for wild bird populations, concern has been expressed regarding the potential for contamination of foodstuffs by mycotoxins, and the implications this might have for wildlife health. We investigated whether aflatoxin (AF) and ochratoxin A (OA) residues are present in foodstuffs sold for wild bird consumption at point of sale in Great Britain using high pressure liquid chromatography analyses. The hypothesis that production of these mycotoxins occurs in British climatic conditions, or under storage conditions after the point of sale, was tested under experimental conditions but was not proved by our study. While the majority of peanut samples were negative for AF residues, 10% (10/98) of samples at point of sale and 11% (13/119) of those across the storage and climate exposure treatment replicates contained AFB1 that exceeded the maximum permitted limit of 20 µg/kg. No significant difference was found in the detection of either mycotoxin between branded and non-branded products. The clinical significance, if any, of exposure of wild birds to mycotoxins requires further investigation. Nevertheless, the precautionary principle should be adopted and best practice steps to reduce the likelihood of wild bird exposure to mycotoxins are recommended.


Assuntos
Aflatoxinas/análise , Micotoxinas/análise , Animais , Aves , Contaminação de Alimentos/análise , Ocratoxinas , Reino Unido
13.
Int J Food Microbiol ; 328: 108666, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32454365

RESUMO

Although Aspergillus flavus and Aspergillus parasiticus are the main microorganisms of concern in peanuts, due to aflatoxin contamination, several Salmonella outbreaks from this product have been reported over the last ten decades. Thus, it is important to understand the relationship between microorganisms to predict, manage and estimate the diversity in the peanut supply chain. The purpose of this study was to evaluate aflatoxin production during the co-cultivation of Aspergillus section Flavi and Salmonella both isolated from peanuts. Three strains of A. section Flavi: A. flavus producing aflatoxin B, A. flavus non-producing aflatoxin and A. parasiticus producing aflatoxin B and G were co-cultivated with seven serotypes of Salmonella of which six were isolated from the peanut supply chain (S. Muenster, S. Miami, S. Glostrup, S. Javiana, S. Oranienburg and S. Yoruba) and one was S. Typhimurium ATCC 14028. First of all, each Salmonella strain was inoculated by pour plate (ca. 5 log cfu/mL) in PDA (potato dextrose agar). Then, each pre-cultured fungus was inoculated in the center of the petri dish. The plates were incubated at 30 °C and the fungal colony diameter was measured once a day for 7 days. As a control each Aspergillus strain was cultivated in the absence of Salmonella culture. All three strains of Aspergillus with absence of Salmonella (control) reached the maximum colony diameter and their growth rate was influenced when co-cultivated (p < 0.05) with all Salmonella serotypes tested. The maximum inhibition in the colony diameter was 20% for A. flavus aflatoxin B producer and A. parasiticus, and 18% for A. flavus non- aflatoxin producer when cultivated with Salmonella. However, no significant difference (p < 0.05) in reduction of colony diameter was observed among the Salmonella serotypes. Aflatoxin production was determined previously, by using the agar plug technique on thin layer chromatography (TLC). The production of aflatoxin G by A. parasiticus in co-cultivation with Salmonella was not observed. On the other hand, A. flavus preserved their characteristics of aflatoxin B production. The quantification of aflatoxin reduction by Salmonella interaction was evaluated using HPLC method. There was a maximum reduction of aflatoxin production of 88.7% and 72.9% in A. flavus and A. parasiticus, respectively, when cultivated with Salmonella. These results indicate that some serotypes of Salmonella may interfere with aflatoxin production and fungal growth of A. flavus and A. parasiticus in the peanut supply chain.


Assuntos
Antibiose/fisiologia , Arachis/microbiologia , Aspergillus flavus/metabolismo , Salmonella/metabolismo , Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus flavus/crescimento & desenvolvimento , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Salmonella/isolamento & purificação
14.
Environ Sci Pollut Res Int ; 27(16): 20125-20135, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32239408

RESUMO

Nanoparticles are widely studied for applications in medical science. In recent years, they have been developed for agronomical purposes to target microbial pest such as bacteria, fungi, and viruses. Nanoparticles are also proposed to limit the use of pesticides, whose abuse is causing environmental impact and human health concerns. In this study, nanoparticles were obtained by using poly-(ε-caprolactone), a polyester chosen for its biocompatibility and biodegradability properties. Poly-(ε-caprolactone) nanoparticles were formulated by using poly(vinyl alcohol) or Pluronic® F127 as non-ionic surfactants, and then loaded with benzophenone or valerophenone thiosemicarbazone, two compounds that inhibit aflatoxin production by Aspergillus flavus. The different types of nanoparticles were compared in terms of size, polydispersity index, morphology, and drug loading capacity. Finally, their effects were investigated on growth, development, and aflatoxin production in the aflatoxigenic species Aspergillus flavus, a ubiquitous contaminant of maize, cereal crops, and derived commodities. Aflatoxin production was inhibited to various extents, but the best inhibitory effect was obtained with respect to sclerotia production that was most effectively suppressed by both benzophenone and valerophenone thiosemicarbazone-loaded nanoparticles. These data support the idea that it is possible to use such nanoparticles as an alternate to pesticides for the control of mycotoxigenic sclerotia-forming fungi.


Assuntos
Aflatoxinas/análise , Tiossemicarbazonas , Aspergillus flavus , Produtos Agrícolas , Zea mays
15.
Food Microbiol ; 90: 103449, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336370

RESUMO

The objective of this work was to assess the efficacy of sodium hypochlorite and peracetic acid for sanitization of Brazil nuts. To evaluate the natural microbiota of the nuts, the total bacteria and fungi as well as the Aspergillus section Flavi were counted. The moisture, water activity and the presence of aflatoxins was quantified. The response surface method was used to determine the influence of exposure time and sanitizers concentration on the reduction of Aspergillus nomius inoculated on the nuts. Microbiological, sensory and quantification analyzes of aflatoxins were performed under optimum conditions The evaluation of the initial contamination of the nuts, despite presenting high microbiological contamination, humidity and water activity, was not detected aflatoxins in any samples. In artificially inoculated samples, the response surface and the desirability function were obtained to determine the optimal point of use for each sanitizer. The nuts had high microbiological contamination, moisture content and water activity. Aflatoxins were not detected in any samples. The response surface and desirability function indicated the optimal sanitization conditions were 250 mg/L and 8.5 min and 140 mg/L and 15 min for sodium hypochlorite and peracetic acid, respectively. Reductions greater than 2 log CFU/g were obtained with sodium hypochlorite and of 1 log CFU/g for peracetic acid. In the tests performed with new Brazil nuts samples under the optimized conditions, reductions of less than 2 log CFU/g were obtained. Aflatoxin B1 was detected in one untreated sample (1.51 µg/kg), one sample treated with sodium hypochlorite (0.60 µg/kg) and two samples treated with peracetic acid (0.64 and 0.72 µg/kg). Demonstrating that the sanitizers in the concentrations used had no action on aflatoxins, despite being efficient for fungal control. The treatments did not cause an unacceptable sensorial impact on the samples.


Assuntos
Aspergillus/efeitos dos fármacos , Bertholletia/microbiologia , Desinfetantes/farmacologia , Contaminação de Alimentos/prevenção & controle , Ácido Peracético/farmacologia , Hipoclorito de Sódio/farmacologia , Aflatoxinas/análise , Microbiologia de Alimentos
16.
J Food Sci ; 85(4): 1353-1360, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32220140

RESUMO

Here, molecular docking simulation was used to predict and compare interactions between a recombinant Trametes sp. C30 laccase from Saccharomyces cerevisiae and four aflatoxins (AFB1 , AFB2 , AFG1 , and AFG2 ) as well as their degradation at a molecular level. The computational result of docking simulation indicates that each of the aflatoxins tested can interact with laccase with a binding ability of AFB1 >AFG2 >AFG1 >AFB2 . Simultaneously, it also demonstrated that aflatoxin B1 , B2 , G1 , G2 may interact near the T1 copper center of the enzyme through H-bonds and hydrophobic interactions with amino acid residues His481 and Asn288; His481; Asn288, and Asp230; His481 and Asn288. Biological degradation test was performed in vitro in the presence of a recombinant laccase. Degradation increased as incubation time increased from 12 to 60 hr and the maximum degradation obtained for AFB1 , AFB2 , AFG1 , and AFG2 was 90.33%, 74.23%, 85.24%, and 87.58%, respectively. Maximum degradation of aflatoxins was determined with a total activity 3 U laccase at 30 °C in 0.1 M phosphate buffer, pH 5.7 after 48-hr incubation. The experimental results are consistent with that of docking calculation on the biological degradation test of four aflatoxins by laccase. PRACTICAL APPLICATION: In this study, the degradation efficiencies of laccase for B and G series of aflatoxins were determined by computer simulation and verified by performing in vitro experiments. It can provide reference for rapid screening of aflatoxin degradation-related enzymes.


Assuntos
Aflatoxinas/metabolismo , Contaminação de Alimentos/análise , Lacase/metabolismo , Saccharomyces cerevisiae/enzimologia , Trametes/enzimologia , Aflatoxina B1/química , Aflatoxinas/análise , Aflatoxinas/química , Cromatografia Líquida de Alta Pressão/métodos , Simulação por Computador , Lacase/genética , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular
17.
Food Microbiol ; 89: 103456, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32139000

RESUMO

The production of aflatoxin (AF) B1 and B2 was determined during malting of wheat grains artificially contaminated with a toxigenic A. flavus strain (CCDCA 11553) isolated from craft beer raw material. Malting was performed in three steps (steeping, germination and kilning) following standard Central European Commission for Brewing Analysis procedures. AFB1 and AFB2 were quantified in eleven samples collected during the three malting steps and in malted wheat. Both, AFB1 and AFB2 were produced at the beginning of steeping and detected in all samples. The levels of AFB1 ranged from 229.35 to 455.66 µg/kg, and from 5.65 to 13.05 µg/kg for AFB2. The AFB2 increased during steeping, while no changes were observed in AFB1. Otherwise, AFB1 decreased during germination and AFB2 did not change. AFB1 and AFB2 increased after 16 h of kilning at 50 °C and decreased at the end of kilning, when the temperature reached 80 °C. The levels of AFB1 wheat malt were lower than those detected in wheat grains during steeping; however, levels of both AFB1 (240.46 µg/kg) and AFB2 (6.36 µg/kg) in Aspergillus flavus inoculated wheat malt exceeded the limits imposed by the regulatory agencies for cereals and derived products.


Assuntos
Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus flavus/metabolismo , Cerveja/análise , Contaminação de Alimentos
18.
Artigo em Inglês | MEDLINE | ID: mdl-32178381

RESUMO

The growing interest in spicy foods leads to the global demand for spices, particularly dried chili. This study aimed to assay both aflatoxin (AFs) and ochratoxin A (OTA) contamination using an integrative method of morphological identification, molecular detection, and chromatography analysis on dried chili provided from traditional and modern markets in Indonesia. The results showed that total fungal infection ranged from 1-408 × 103 CFU/g. Eighty percent of the chili obtained from both the traditional and the modern markets were infected by Aspergillus spp., in which 50% of the infections were identified as A. parasiticus and A. flavus. A complete set of targeted genes involved in AF production and OTA were detected in two isolates of A. flavus and one isolate of A. carbonarius, respectively. The levels of AFs B1, B2, and OTA in the contaminated dried chilies were in the range of 39.3-139.5 µg/kg, 2.6-33.3 µg/kg, and 23.7-84.6 µg/kg, respectively. In contrast, no AFs G1 and G2 were detected. This study showed that the fungal infection of Indonesian dried chili occurs both in the field and during storage; thus, it is suggested to implement good agricultural and handling processes.


Assuntos
Aflatoxinas , Microbiologia de Alimentos , Alimentos em Conserva , Ocratoxinas , Aflatoxinas/análise , Aspergillus/genética , Aspergillus/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Alimentos em Conserva/análise , Alimentos em Conserva/microbiologia , Indonésia , Ocratoxinas/análise
19.
Mikrochim Acta ; 187(3): 167, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32055989

RESUMO

A paper based sensor array is presented to discriminate and determine five mycotoxins classified into three categories, namely aflatoxins, ochratoxins and zearalenone. The gold and silver nanoparticles, synthesized by three different reducing or capping agents, were employed as sensing elements of the fabricated device. These nanoparticles were poured onto hydrophilic circular zones embedded on the hydrophobic substrate. The response of the assay is dependent on the aggregation of nanoparticles for interaction with mycotoxins. Due to aggregation, the gold and silver nanoparticles changed to purple and brown, respectively. Color changes provide unique colorimetric signatures conducive to recognizing the type of mycotoxin, identifying its chemical structure, and finding the fungi that produce it. The discrimination ability of the assay was investigated by both supervised (linear discriminate analysis) and unsupervised (principle component analysis and hierarchical cluster analysis) pattern recognition methods. The assay was applied to the point of need determination of aflatoxin B1, aflatoxin G1, aflatoxin M1, ochratoxin A and zearalenone with a detection limit of 2.7, 7.3, 2.1, 3.3 and 7.0 ng.mL-1, respectively. The fabricated device has high potential of simultaneously determining the mycotoxins in pistachio, wheat, coffee and milk with the help of partial least square method. The root mean square errors for prediction of PLS model were 5.7, 5.2, 1.5, 7.2 and 2.9 for aflatoxin B1, aflatoxin G1, aflatoxin M1, ochratoxin A and zearalenone, respectively. Graphical abstractSchematic representation of paper based colorimetric sensor array based on gold and silver nanoparticles for both qualitative and quantitative analysis of aflatoxins, ochratoxin and zearalenone.


Assuntos
Aflatoxinas/análise , Colorimetria/métodos , Ouro/química , Nanopartículas Metálicas/química , Ocratoxinas/análise , Prata/química , Zearalenona/análise , Colorimetria/instrumentação , Humanos , Papel
20.
J Food Prot ; 83(3): 497-502, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32068855

RESUMO

ABSTRACT: This study was conducted to investigate possible contamination by aflatoxins (AFs) and aflatoxigenic fungi in imported chia seeds consumed in Thailand. A survey was performed on 100 samples of imported chia seeds collected from supermarkets and health food stores in Bangkok from May 2017 to February 2018. Ten mold species belonging to Aspergillus and Penicillium were isolated, and Aspergillus flavus was the most prevalent aflatoxigenic fungi. Chia seed samples were cleaned with an immunoaffinity column and analyzed for AFs by high-performance liquid chromatography with fluorescence detection using precolumn derivatization. AFs were detected in 40% of total samples at concentrations of 0.4 to 10.99 ng/g. Among the positive samples, three were contaminated with total AFs at concentrations higher than the European Union regulatory limit (4 ng/g). The most commonly found AF found in chia seeds was AFB1.


Assuntos
Aflatoxinas , Contaminação de Alimentos/análise , Salvia/química , Aflatoxinas/análise , Aspergillus , Aspergillus flavus , Cromatografia Líquida de Alta Pressão , Fungos , Sementes/química , Tailândia
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