Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Basic Microbiol ; 61(2): 165-176, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33448033

RESUMO

Sugarcane/peanut intercropping is a highly efficient planting pattern in South China. However, the effects of sugarcane/peanut intercropping on soil quality need to be clarified. This study characterized the soil microbial community and the soil quality in sugarcane/peanut intercropping systems by the Illumina MiSeq platform. The results showed that the intercropping sugarcane (IS) system significantly increased the total N (TN), available N (AN), available P (AP), pH value, and acid phosphatase activity (ACP), but it had little effect on the total P (TP), total K (TK), available K (AK), organic matter (OM), urease activity, protease activity, catalase activity, and sucrase activity, compared with those in monocropping sugarcane (MS) and monocropping peanut (MP) systems. Both intercropping peanut (IP) and IS soils contained more bacteria and fungi than soils in the MP and MS fields, and the microbes identified were mainly Chloroflexi and Acidobacteria, respectively. Intercropping significantly increased the number of unique microbes in IS soils (68 genera), compared with the numbers in the IP (14), MS (17), and MP (16) systems. The redundancy analysis revealed that the abundances of culturable Acidobacteriaceae subgroup 1, nonculturable DA111, and culturable Acidobacteria were positively correlated with the measured soil quality in the intercropping system. Furthermore, the sugarcane/peanut intercropping significantly increased the economic benefit by 87.84% and 36.38%, as compared with that of the MP and MS, respectively. These results suggest that peanut and sugarcane intercropping increases the available N and P content by increasing the abundance of rhizospheric microbes, especially Acidobacteriaceae subgroup 1, DA111, and Acidobacteria.


Assuntos
Agricultura/métodos , Arachis/crescimento & desenvolvimento , Saccharum/crescimento & desenvolvimento , Microbiologia do Solo , Solo/química , Fosfatase Ácida/análise , Agricultura/economia , Arachis/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Concentração de Íons de Hidrogênio , Microbiota , Nitrogênio/análise , Fosfatos/análise , Saccharum/microbiologia
2.
Int J Biol Macromol ; 171: 480-490, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33428956

RESUMO

In this study, a comparative efficacy of Cananga odorata EO (CoEO) and its nanoencapsulated formulation into chitosan nanoemulsion (CoEO-CsNe) against a toxigenic strain of Aspergillus flavus (AF-M-K5) were investigated for the first time in order to determine its efficacy in preservation of stored food from fungal, aflatoxin B1 (AFB1) contamination and lipid peroxidation. GC and GC-MS analysis of CoEO revealed the presence of linalool (24.56%) and benzyl acetate (22.43%) as the major components. CoEO was encapsulated into chitosan nanoemulsion (CsNe) through ionic-gelation technique and characterized by High Resolution-Scanning Electron Microscopy (HR-SEM), Fourier Transform Infrared spectroscopy (FTIR), and X-Ray Diffraction (XRD) analysis. The CoEO-CsNe during in vitro investigation against A. flavus completely inhibited the growth and AFB1 production at 1.0 µL/mL and 0.75 µL/mL, respectively. Additionally, CoEO-CsNe showed improved antioxidant activity against DPPH• and ABTS•+ with IC50 value 0.93 and 0.72 µL/mL, respectively. Further, CoEO-CsNe suppressed fungal growth, AFB1 secretion and lipid peroxidation in Arachis hypogea L. during in situ investigation without causing any adverse effect on seed germination. Overall results demonstrated that the CoEO-CsNe has potential of being utilized as a suitable plant based antifungal agent to improve the shelf-life of stored food against AFB1 and lipid peroxidation mediated biodeterioration.


Assuntos
Antifúngicos/administração & dosagem , Antioxidantes/administração & dosagem , Arachis/microbiologia , Aspergillus flavus/efeitos dos fármacos , Cananga/química , Conservantes de Alimentos/administração & dosagem , Nanocápsulas/administração & dosagem , Óleos Voláteis/administração & dosagem , Óleos de Plantas/administração & dosagem , Aflatoxina B1/metabolismo , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Aspergillus flavus/metabolismo , Avaliação Pré-Clínica de Medicamentos , Emulsões , Conservantes de Alimentos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Germinação/efeitos dos fármacos , Química Verde , Concentração Inibidora 50 , Peroxidação de Lipídeos/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Sementes/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
3.
Ultrason Sonochem ; 59: 104728, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421619

RESUMO

Ultra-sonication (US) at varying intensities (200 W, 300 W and 400 W) and hydrodynamic cavitation (HC) at increasing pressures (6 bar, 8 bar and 10 bar) on freshly extracted peanut milk as non-thermal processing of milk for enhanced quality. The effects of US and HC was investigated on physico-chemical properties of peanut milk, microbial inactivation (total plate count and yeasts and molds), microstructure by optical microscopy and particle size, ζ-potential, sedimentation index, rheology and color measurements. The high temperature short time (HTST) treated milk samples have shown 1.53 and 2 log reduction in TPC, yeast and molds respectively with highest protein hydrolysis of 15.7%. Among the non-thermal treatments HC has shown highest log reduction of TPC at around 1.2 for sample treated at 10 bar pressure, whereas the US treatment was most effective for yeast and mold at 400 W with log reduction of 0.9. A non-Newtonian flow behaviour was observed for all peanut milk samples. Viscosity determined by Herschel-Bulkley equation decreased significantly (p > 0.05) after both cavitation treatments. The US was found to be superior to HC and HTST with improved separation index and colour attributes. Therefore, the US and HC appear to be a remarkable non-thermal processing methods for peanut milk and or any dairy or non-dairy beverages.


Assuntos
Arachis/química , Bebidas/microbiologia , Fenômenos Químicos , Hidrodinâmica , Viabilidade Microbiana , Sonicação , Arachis/microbiologia , Cor , Concentração de Íons de Hidrogênio , Hidrólise , Fenômenos Ópticos , Tamanho da Partícula , Proteínas de Plantas/química , Solubilidade , Temperatura
4.
Toxicol Lett ; 314: 75-81, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31284020

RESUMO

Aflatoxin is a fungal secondary metabolite with high toxicity that is capable of contaminating various types of food crops. It has been identified as a Group 1 human carcinogen by the International Agency for Research on Cancer. Chronic aflatoxin exposure has caused worldwide concern as a matter of public food safety. Peanuts and peanut products are the major sources of aflatoxin exposure. Therefore, some reduction interventions have been developed to minimize contamination throughout the peanut production chain. The purpose of this study is to estimate the efficacy of interventions in reducing the health impact of hepatocellular carcinoma caused by aflatoxin contamination in peanuts. The estimated total Disability-Adjusted Life Years (DALYs) were calculated using FDA-iRISK software. Six aflatoxin reduction strategies were evaluated, including good agricultural practice (GAP), biocontrol, Purdue Improved Crop Storage packaging, basic processing, ozonolysis, and ultraviolet irradiation. The results indicated that basic processing could prevent huge public health loss of 4,079.7-21,833 total DALYs per year. In addition, GAP and biocontrol were both found to be effective strategies in the farm field. Meanwhile, the other three interventions had limited effectiveness in reducing total DALYs. In conclusion, this study could help farmers, processing plants, and government policy makers to alleviate aflatoxin contamination issues in the peanut production chain.


Assuntos
Aflatoxinas/efeitos adversos , Arachis/microbiologia , Carcinoma Hepatocelular/prevenção & controle , Produtos Agrícolas/microbiologia , Exposição Dietética/efeitos adversos , Exposição Dietética/prevenção & controle , Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Anos de Vida Ajustados por Qualidade de Vida , Agentes de Controle Biológico , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/epidemiologia , Efeitos Psicossociais da Doença , Avaliação da Deficiência , Manipulação de Alimentos/métodos , Armazenamento de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/epidemiologia , Ozônio/química , Fatores de Proteção , Medição de Risco , Fatores de Risco , Fatores de Tempo , Raios Ultravioleta
5.
Food Microbiol ; 83: 187-192, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31202412

RESUMO

The control of Salmonella in low water activity foods poses a challenge for the food industry because of its thermal resistance. The use of surrogate bacteria in a food plant is considered a critical component to validate processing steps. The objective of this study was to evaluate the use of Pediococcus acidilactici ATCC 8042, a generally recognized as safe bacterium (GRAS), as potential surrogate for Salmonella in commercial toasted oats cereal (TOC) and peanut butter. P. acidilactici was compared to a five-serovar cocktail of Salmonella and Enterococcus faecium NRRL-B2354, separately. Cultures were inoculated into TOC and thermal kinetic parameters (δ, ß) were determined at 80, 85, 90, and 95 °C using the Weibull model. In peanut butter, δ and ß parameters were obtained at 63, 68, 73, and 77 °C. In TOC, the δ values (initial decimal reduction time) of P. acidilactici were 63 and 7 min at 80 and 95 °C, respectively, and at all four temperatures they were not significantly different from δ values of E. faecium. The δ value of Salmonella at 80 °C (139 min) was two-fold greater than the other two bacteria's values (p < 0.05). In peanut butter, δ values of P. acidilactici ranged from 31 min at 63 °C to 2.6 min at 77 °C, and at all temperatures they were not significantly different from E. faecium's δ values. In peanut butter, all Salmonella cocktail's δ values were significantly smaller than P. acidilactici's with values of 2 min at 63 °C and 0.4 min at 77 °C. These results indicated that P. acidilactici was as heat tolerant as E. faecium in these food matrices. However, the thermal inactivation kinetic parameters suggested that P. acidilactici can only be considered a Salmonella surrogate in TOC at temperatures above 85 °C. Because of its greater thermal tolerance in peanut butter, P. acidilactici may be used as Salmonella surrogate if an additional safety factor is recommended.


Assuntos
Arachis/microbiologia , Avena/microbiologia , Microbiologia de Alimentos/métodos , Viabilidade Microbiana , Pediococcus acidilactici/fisiologia , Termotolerância , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor/normas , Temperatura Alta , Cinética , Salmonella/fisiologia
6.
Microbiol Res ; 205: 118-124, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28942837

RESUMO

Phenolic acids can enhance the mycotoxin production and activities of hydrolytic enzymes related to pathogenicity of soilborne fungus Fusarium oxysporum. However, characteristics of phenolic acid-degrading bacteria have not been investigated. The objectives of this study were to isolate and characterize bacteria capable of growth on benzoic and vanillic acids as the sole carbon source in the peanut rhizosphere. Twenty-four bacteria were isolated, and the identification based on 16S rRNA gene sequencing revealed that pre-exposure to phenolic acids before sowing shifted the dominant culturable bacterial degraders from Arthrobacter to Burkholderia stabilis-like isolates. Both Arthrobacter and B. stabilis-like isolates catalysed the aromatic ring cleavage via the ortho pathway, and Arthrobacter isolates did not exhibit higher C12O enzyme activity than B. stabilis-like isolates. The culture filtrate of Fusarium sp. ACCC36194 caused a strong inhibition of Arthrobacter growth but not B. stabilis-like isolates. Additionally, Arthrobacter isolates responded differently to the culture filtrates of B. stabilis-like isolates. The Arthrobacter isolates produced higher indole acetic acid (IAA) levels than B. stabilis-like isolates, but B. stabilis-like isolates were also able to produce siderophores, solubilize mineral phosphate, and exert an antagonistic activity against peanut root rot pathogen Fusarium sp. ACCC36194. Results indicate that phenolic acids can shift their dominant culturable bacterial degraders from Arthrobacter to Burkholderia species in the peanut rhizosphere, and microbial interactions might lead to the reduction of culturable Arthrobacter. Furthermore, increasing bacterial populations metabolizing phenolic acids in monoculture fields might be a control strategy for soilborne diseases caused by Fusarium spp.


Assuntos
Arachis/microbiologia , Bactérias/metabolismo , Agentes de Controle Biológico , Hidroxibenzoatos/metabolismo , Doenças das Plantas/prevenção & controle , Rizosfera , Antibiose , Arachis/crescimento & desenvolvimento , Arthrobacter/enzimologia , Arthrobacter/crescimento & desenvolvimento , Arthrobacter/isolamento & purificação , Arthrobacter/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Ácido Benzoico/metabolismo , Burkholderia/enzimologia , Burkholderia/crescimento & desenvolvimento , Burkholderia/isolamento & purificação , Burkholderia/metabolismo , Catecol 1,2-Dioxigenase/metabolismo , Catecol 2,3-Dioxigenase/metabolismo , Fusarium/patogenicidade , Hidroxibenzoatos/farmacologia , Ácidos Indolacéticos/metabolismo , Fosfatos/metabolismo , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Sideróforos/metabolismo , Solo , Microbiologia do Solo , Ácido Vanílico/metabolismo
7.
J Food Prot ; 80(9): 1451-1460, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28782996

RESUMO

In Nigeria, Aflasafe is a registered biological product for reducing aflatoxin infestation of crops from the field to storage, making the crops safer for consumption. The important questions are whether farmers will purchase and apply this product to reduce aflatoxin contamination of crops, and if so under what conditions. A study was carried out to address these questions and assess determinants of willingness to pay (WTP) for the product among maize and groundnut farmers in Kano and Kaduna states in Nigeria. A multistage sampling technique was used to collect primary data from 492 farmers. The majority of farmers who had direct experience with Aflasafe (experienced farmers) in Kano (80.7%) and Kaduna (84.3%) had a WTP bid value equal to or greater than the threshold price ($10) at which Aflasafe was to be sold. The mean WTP estimates for Aflasafe for experienced farmers in Kano and Kaduna were statistically the same. However, values of $3.56 and $7.46 were offered in Kano and Kaduna states, respectively, by farmers who had never applied Aflasafe (inexperienced farmers), and the difference here was significant (P < 0.01). Regression results indicate that contact with extension agents (P < 0.01) and access to credit (P < 0.05) positively and significantly influenced the probability that a farmer would be willing to pay more for Aflasafe than the threshold price. Lack of awareness of the importance of Aflasafe was the major reason cited by inexperienced farmers (64% in Kano state and 21% in Kaduna state) for not using the product. A market strategy promoting a premium price for aflatoxin-safe produce and creating awareness and explaining the availability of Aflasafe to potential users should increase Aflasafe usage.


Assuntos
Aflatoxinas/análise , Serviços de Saúde Comunitária/economia , Fazendeiros/psicologia , Financiamento Pessoal , Arachis/química , Arachis/microbiologia , Redes Comunitárias , Humanos , Nigéria , Controle Biológico de Vetores/economia , Zea mays/química , Zea mays/microbiologia
8.
Int J Food Microbiol ; 251: 24-32, 2017 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-28380344

RESUMO

The fungal and multi-mycotoxin profiles of groundnuts sold in domestic markets in Nigeria as well as the associated risk to consumers were assessed in the present study. Four hundred fungal isolates representing mainly Aspergillus [58.6%: Aspergillus section Flavi (37.1%) and A. niger-clade (21.5%)], Penicillium (40.9%) and Fusarium (0.5%) were isolated from 82 (97.6%, n=84) groundnut samples collected from four agro-ecological zones (AEZs) of Nigeria. The incidence of aflatoxin-producing A. flavus isolates (71%) was significantly (p<0.05) higher in the groundnuts than that of the non-aflatoxigenic isolates (29%). Fifty-four fungal metabolites [including aflatoxins (AFB1, AFB2, AFG1, AFG2 and AFM1), beauvericin (BEAU), cyclopiazonic acid (CPA), moniliformin, nivalenol and ochratoxin A] and four bacterial metabolites were detected in the groundnuts by liquid chromatography tandem mass spectrometry. Aflatoxins (39%; max: 2076µg/kg; mean: 216µg/kg) were detected in more samples than any other mycotoxin. About 25, 23 and 14% of the samples respectively were above the 2µg/kg AFB1, 4 and 20µg/kg total aflatoxin limits of the European Union and US FDA respectively. The mean margins of exposure of AFB1 and total aflatoxins for adult consumers were 1665 and 908, respectively, while mean estimated daily intake values for infants, children and adults were <0.1% for BEAU and 4% for CPA. Consumers of mycotoxin contaminated groundnuts in Nigeria may therefore be at a risk of liver cancer in addition to other combinatory effects of mycotoxin/metabolite cocktails. There is need for increased targeted interventions in the groundnut value chain in Nigeria for public health benefits.


Assuntos
Arachis/química , Arachis/microbiologia , Aspergillus flavus/isolamento & purificação , Fusarium/isolamento & purificação , Micotoxinas/análise , Nozes/química , Nozes/microbiologia , Penicillium/isolamento & purificação , Aflatoxinas/análise , Aspergillus flavus/metabolismo , Cromatografia Líquida , Ciclobutanos/análise , Depsipeptídeos/análise , Fusarium/metabolismo , Humanos , Indóis/análise , Lactente , Neoplasias Hepáticas/epidemiologia , Nigéria/epidemiologia , Ocratoxinas/análise , Penicillium/metabolismo , Medição de Risco , Espectrometria de Massas em Tandem , Tricotecenos/análise
9.
Food Addit Contam Part B Surveill ; 9(4): 290-298, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27748169

RESUMO

This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers' management practices. A total of 160 groundnut seed samples from farmers' stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g-1 from 2013/2014 and 2014/2015 samples, respectively. The level of specific aflatoxin concentration varied between 0.1 and 2526 ng g-1 for B2 and B1, respectively. Among contaminated samples of groundnut cake, 68% exhibited aflatoxin concentration below 20 ng g-1, while as high as 158 ng g-1 aflatoxin B1 was recorded. The study confirms high contamination of groundnut products in East Ethiopia.


Assuntos
Aflatoxinas/análise , Arachis/microbiologia , Aspergillus/isolamento & purificação , Culinária , Produtos Agrícolas/microbiologia , Contaminação de Alimentos , Sementes/microbiologia , Aflatoxina B1/análise , Aflatoxina B1/biossíntese , Aflatoxina B1/toxicidade , Aflatoxinas/biossíntese , Aflatoxinas/toxicidade , Agricultura/métodos , Arachis/efeitos adversos , Arachis/química , Arachis/crescimento & desenvolvimento , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/metabolismo , Cromatografia Líquida de Alta Pressão , Produtos Agrícolas/efeitos adversos , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Dieta/efeitos adversos , Dieta/etnologia , Etiópia , Fast Foods/efeitos adversos , Fast Foods/análise , Fast Foods/economia , Fast Foods/microbiologia , Inspeção de Alimentos , Armazenamento de Alimentos , Humanos , Restaurantes , Sementes/efeitos adversos , Sementes/química , Sementes/crescimento & desenvolvimento , Análise Espaço-Temporal
10.
Toxins (Basel) ; 7(10): 4157-74, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26501322

RESUMO

Based on the 2983 peanut samples from 122 counties in six provinces of China's Yangtze River ecological region collected between 2009-2014, along with the dietary consumption data in Chinese resident nutrition and health survey reports from 2002 and 2004, dietary aflatoxin exposure and percentiles in the corresponding statistics were calculated by non-parametric probability assessment, Monte Carlo simulation and bootstrap sampling methods. Average climatic conditions in the Yangtze River ecological region were calculated based on the data from 118 weather stations via the Thiessen polygon method. The survey results found that the aflatoxin contamination of peanuts was significantly high in 2013. The determination coefficient (R²) of multiple regression reflected by the aflatoxin B1 content with average precipitation and mean temperature in different periods showed that climatic conditions one month before harvest had the strongest impact on aflatoxin B1 contamination, and that Hunan and Jiangxi provinces were greatly influenced. The simulated mean aflatoxin B1 intake from peanuts at the mean peanut consumption level was 0.777-0.790 and 0.343-0.349 ng/(kg·d) for children aged 2-6 and standard adults respectively. Moreover, the evaluated cancer risks were 0.024 and 0.011/(100,000 persons·year) respectively, generally less than China's current liver cancer incidence of 24.6 cases/(100,000 persons·year). In general, the dietary risk caused by peanut production and harvest was low. Further studies would focus on the impacts of peanut circulation and storage on aflatoxin B1 contamination risk assessment in order to protect peanut consumers' safety and boost international trade.


Assuntos
Aflatoxina B1/análise , Arachis/química , Exposição Ambiental/análise , Contaminação de Alimentos/análise , Nozes/química , Adulto , Arachis/crescimento & desenvolvimento , Arachis/microbiologia , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Criança , Pré-Escolar , China , Cromatografia Líquida de Alta Pressão , Clima , Ecossistema , Exposição Ambiental/estatística & dados numéricos , Contaminação de Alimentos/estatística & dados numéricos , Humanos , Método de Monte Carlo , Nozes/microbiologia , Análise de Regressão , Medição de Risco , Rios
11.
PLoS One ; 9(3): e90901, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24595464

RESUMO

A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI) is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2) and a stilbenoid (resveratrol). Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs.


Assuntos
Aflatoxinas/análise , Arachis/química , Micotoxinas/análise , Sesquiterpenos/análise , Estilbenos/análise , Arachis/microbiologia , Contaminação de Alimentos/análise , Espectrometria de Massas/economia , Espectrometria de Massas/métodos , Nozes/química , Nozes/microbiologia , Resveratrol , Dióxido de Silício/química , Fitoalexinas
12.
Toxicol Sci ; 135(1): 251-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23761295

RESUMO

The aflatoxins are a group of fungal metabolites that contaminate a variety of staple crops, including maize and peanuts, and cause an array of acute and chronic human health effects. Aflatoxin B1 in particular is a potent liver carcinogen, and hepatocellular carcinoma (HCC) risk is multiplicatively higher for individuals exposed to both aflatoxin and chronic infection with hepatitis B virus (HBV). In this work, we sought to answer the question: do current aflatoxin regulatory standards around the world adequately protect human health? Depending upon the level of protection desired, the answer to this question varies. Currently, most nations have a maximum tolerable level of total aflatoxins in maize and peanuts ranging from 4 to 20ng/g. If the level of protection desired is that aflatoxin exposures would not increase lifetime HCC risk by more than 1 in 100,000 cases in the population, then most current regulatory standards are not adequately protective even if enforced, especially in low-income countries where large amounts of maize and peanuts are consumed and HBV prevalence is high. At the protection level of 1 in 10,000 lifetime HCC cases in the population, however, almost all aflatoxin regulations worldwide are adequately protective, with the exception of several nations in Africa and Latin America.


Assuntos
Aflatoxinas/toxicidade , Arachis/microbiologia , Inocuidade dos Alimentos , Medição de Risco , Zea mays/microbiologia , Aflatoxinas/análise , Arachis/normas , Carcinoma Hepatocelular/etiologia , Hepatite B/complicações , Humanos , Neoplasias Hepáticas/etiologia , Zea mays/normas
13.
Biosens Bioelectron ; 49: 426-32, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23807236

RESUMO

Mycotoxins are highly toxic contaminants and have induced health threat to human and animals. Aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEA) commonly occur in food and feed. A multi-component immunochromatographic assay (ICA) was developed for rapid and simultaneous determination of these three mycotoxins in agro-food. The strategy was performed based on the competitive immunoreactions between antibody-colloidal gold nanoparticle conjugate probes and mycotoxins or mycotixin antigens. Each monoclonal antibody specially recognize its corresponding mycotoxin and antigen, and there was no cross reactivity in the assay. Three mycotixin antigens were immobilized as three test lines in the nitrocellulose membrane reaction zone, which enable the simultaneous detection in one single test. The visible ICA results were obtained in 20 min. The visual detection limits of this strip test for the AFB1, OTA and ZEA were 0.25 ng/mL, 0.5 ng/mL and 1 ng/mL, respectively. The assay was evaluated using spiked and naturally contaminated peanuts, maize and rice samples. The results were in accordance with those obtained using enzyme-linked immunosorbent assay. In summary, this developed ICA could provide an effective and rapid approach for onsite detection of multi-mycotoxin in agro-food samples without any expensive instrument.


Assuntos
Aflatoxina B1/análise , Cromatografia de Afinidade/instrumentação , Contaminação de Alimentos/análise , Ocratoxinas/análise , Zearalenona/análise , Animais , Anticorpos Imobilizados/química , Arachis/microbiologia , Cromatografia de Afinidade/economia , Desenho de Equipamento , Microbiologia de Alimentos/economia , Microbiologia de Alimentos/instrumentação , Coloide de Ouro/química , Humanos , Limite de Detecção , Oryza/microbiologia , Zea mays/microbiologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-24786411

RESUMO

Exposure to aflatoxins in the adult Malaysian diet was estimated by analysing aflatoxins in 236 food composites prepared as "ready for consumption". Dietary exposure to aflatoxin B1 (AFB1) ranged from 24.3 to 34.00 ng/kg b.w./day (lower to upper bound), with peanuts being the main contributor. Estimated liver cancer risk from this exposure was 0.61-0.85 cancers/100,000 population/year, contributing 12.4%-17.3% of the liver cancer cases. Excluding AFB1 occurrence data higher than 15 µg/kg reduced exposure by 65%-91% to 2.27-11.99 ng/kg b.w./day, reducing the cancer risk to 0.06-0.30 cancers/100,000 population/year (contributing 1.2%-6.1% liver cancer cases). Reducing further the ML of AFB1 from 15 to 5 µg/kg yielded 3%-7% greater drop in the exposure to 0.47-10.26 ng/kg b.w./day with an estimated risk of 0.01-0.26 cancers/100,000 population/year (0.2%-5.1% liver cancer cases attributed to dietary AFB1). These findings indicate that current MLs are adequate in protecting Malaysians' health.


Assuntos
Aflatoxina B1/análise , Arachis , Dieta , Exposição Ambiental/análise , Contaminação de Alimentos/análise , Neoplasias Hepáticas/induzido quimicamente , Nozes , Adulto , Aflatoxina B1/efeitos adversos , Arachis/microbiologia , Exposição Ambiental/efeitos adversos , Fungos , Humanos , Malásia , Nozes/microbiologia , Medição de Risco , Fatores de Risco
15.
Artigo em Inglês | MEDLINE | ID: mdl-20455160

RESUMO

Public health interventions must be readily accepted by their target populations to have any meaningful impact and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed. At the same time, these interventions must be assessed for potential unintended consequences, either to the environment or to human health. In this paper, we evaluate the technical feasibility of interventions to control aflatoxin risk, to be potentially deployed in parts of Africa where aflatoxin exposure poses a significant public health concern. We have applied a conceptual framework for feasibility to four interventions, one associated with each of four different stages of aflatoxin risk: biocontrol (pre-harvest), a post-harvest intervention package (post-harvest), NovaSil clay (dietary), and hepatitis B vaccination (clinical). For each intervention, we have assessed the following four components of technical feasibility: (1) characteristics of the basic intervention, (2) characteristics of delivery, (3) requirements on government capacity, and (4) usage characteristics. We propose ways in which feasibility of each intervention is currently high or low from the perspective of adoption in Africa, how public education is crucial for each of these interventions to succeed, and how to align economic incentives to make the interventions more suitable for less developed countries.


Assuntos
Aflatoxinas/toxicidade , Aspergillus/metabolismo , Produtos Agrícolas/química , Produtos Agrícolas/microbiologia , Contaminação de Alimentos/prevenção & controle , Medição de Risco/métodos , Aflatoxinas/biossíntese , Aflatoxinas/normas , África , Agricultura/economia , Agricultura/legislação & jurisprudência , Agricultura/métodos , Arachis/química , Arachis/microbiologia , Países em Desenvolvimento/economia , Dieta , Grão Comestível/química , Grão Comestível/microbiologia , Estudos de Viabilidade , Manipulação de Alimentos/economia , Manipulação de Alimentos/legislação & jurisprudência , Manipulação de Alimentos/métodos , Doenças Transmitidas por Alimentos/prevenção & controle , Política de Saúde/economia , Política de Saúde/legislação & jurisprudência , Promoção da Saúde , Vacinas contra Hepatite B/administração & dosagem , Humanos , Prática de Saúde Pública/economia , Prática de Saúde Pública/legislação & jurisprudência
16.
Artigo em Inglês | MEDLINE | ID: mdl-20234965

RESUMO

Advances in health economics have proven useful in evaluating the cost-effectiveness of interventions, where the benefit usually takes the form of improved health outcomes rather than market outcomes. The paper performs health-based cost-effectiveness analyses of two potential aflatoxin control strategies in Africa: (1) pre-harvest biocontrol, using atoxigenic strains of Aspergillus flavus competitively to exclude toxigenic strains from colonizing maize in Nigeria; and (2) post-harvest interventions in a package to reduce aflatoxin accumulation in groundnuts in Guinea. It is described how health benefits gained from each intervention, in terms of fewer aflatoxin-induced hepatocellular carcinoma cases, can be compared with the costs of implementing the interventions. It is found that both interventions would be extremely cost-effective if applied widely in African agriculture. That is, the monetized value of lives saved and quality of life gained by reducing aflatoxin-induced hepatocellular carcinoma far exceeds the cost of either biocontrol or the post-harvest intervention package to achieve those health benefits. The estimated cost-effectiveness ratio (CER; gross domestic product multiplied by disability-adjusted life years saved per unit cost) for biocontrol in Nigerian maize ranged from 5.10 to 24.8; while the estimated CER for the post-harvest intervention package in Guinean groundnuts ranged from 0.21 to 2.08. Any intervention with a CER > 1 is considered by the World Health Organization (WHO) to be 'very cost-effective', while an intervention with a CER > 0.33 is considered 'cost-effective'. Aside from cost-effectiveness, public health interventions must be readily accepted by the public, and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed.


Assuntos
Aflatoxinas/análise , Aflatoxinas/toxicidade , Contaminação de Alimentos/economia , Contaminação de Alimentos/prevenção & controle , Controle Biológico de Vetores/economia , África , Arachis/química , Arachis/microbiologia , Aspergillus , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/prevenção & controle , Análise Custo-Benefício , Dieta , Contaminação de Alimentos/análise , Guiné , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/prevenção & controle , Nigéria , Zea mays/química , Zea mays/microbiologia
17.
J Genet Genomics ; 34(6): 544-54, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17601614

RESUMO

Bacterial wilt (BW) caused by Ralstonia solanacearum is an important constraint to peanut (Arachis hypogaea L.) production in several Asian and African countries, and planting BW-resistant cultivars is the most feasible method for controlling the disease. Although several BW-resistant peanut germplasm accessions have been identified, the genetic diversity among these has not been properly investigated, which has impeded efficient utilization. In this study, the genetic relationships of 31 peanut genotypes with various levels of resistance to BW were assessed based on SSR and AFLP analyses. Twenty-nine of 78 SSR primers and 32 of 126 AFLP primer combinations employed in this study were polymorphic amongst the peanut genotypes tested. The SSR primers amplified 91 polymorphic loci in total with an average of 3.14 alleles per primer, and the AFLP primers amplified 72 polymorphic loci in total with an average of 2.25 alleles per primer. Four SSR primers (14H06, 7G02, 3A8, 16C6) and one AFLP primer (P1M62) were found to be most efficient in detecting diversity. The genetic distance between pairs of genotypes ranged from 0.12 to 0.94 with an average of 0.53 in the SSR data and from 0.06 to 0.57 with an average of 0.25 in the AFLP data. The SSR-based estimates of the genetic distance were generally larger than that based on the AFLP data. The genotypes belonging to subsp. fastigiata possessed wider diversity than that of subsp. hypogaea. The clustering of genotypes based on the SSR and AFLP data were similar but the SSR clustering was more consistent with morphological classification of A. hypogaea. Optimum diverse genotypes of both subsp. hypogaea and subsp. fastigiata can be recommended based on this analysis for developing mapping populations and breeding for high yielding and resistant cultivars.


Assuntos
Arachis/genética , Arachis/microbiologia , Variação Genética , Imunidade Inata/genética , Repetições Minissatélites/genética , Doenças das Plantas/imunologia , Ralstonia solanacearum/fisiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Arachis/imunologia , Genótipo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo Genético
18.
Environ Sci Technol ; 38(15): 4049-55, 2004 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15352440

RESUMO

The 2003 Council for Agricultural Science and Technology Mycotoxin report states that one 21st century goal is the development of uniform regulations worldwide for foodborne mycotoxin contamination. This study informs that endeavor by a risk assessment and economic analysis of two important mycotoxins: fumonisins and aflatoxins. The goals are to identify the nations that would be most heavily impacted by tighter mycotoxin regulations, examine costs and benefits as a function of regulatory stringency, and address risk-risk tradeoffs between health benefits and economic losses from compliance with those regulations. Among industrial nations, the United States would experience the heaviest economic losses from more precautionary mycotoxin standards. Environmental conditions in the developing world, however, are more conducive to mycotoxin accumulation in crops. Contrary to concerns expressed among policymakers, the less developed countries that would likely experience the greatest loss from tighter mycotoxin standards are not sub-Saharan African nations, but China and Argentina. If a fumonisin standard of 0.5 mg/kg were adopted worldwide, total export losses from fumonisins in corn may exceed 300 million dollars annually: 3-fold higher than if the less stringent U.S. standard of 2 mg/kg were adopted. Likewise, export losses from aflatoxins in peanuts may exceed 450 million dollars under the current EU regulatory standard of 4 microg/kg: almost 5-fold higher than if the U.S. standard of 20 microg/kg were adopted. Stricter standards are unlikely to improve health significantly. In developing nations such as China where hepatitis B and C are prevalent, tighter aflatoxin standards may increase health risks until improved control methods for aflatoxins are found, as high-quality crops may be exported instead of being consumed domestically.


Assuntos
Aflatoxinas/normas , Comércio/normas , Contaminação de Alimentos/legislação & jurisprudência , Fumonisinas/normas , Saúde Global , Aflatoxinas/economia , Arachis/microbiologia , Comércio/economia , Contaminação de Alimentos/economia , Contaminação de Alimentos/prevenção & controle , Fumonisinas/economia , Regulamentação Governamental , Medição de Risco , Estados Unidos , United States Food and Drug Administration , Zea mays/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA