Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.010
Filtrar
1.
J Agric Food Chem ; 68(1): 206-212, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31808686

RESUMO

The present study aimed to investigate the effects of matured hop bitter acids (MHBAs) on human cognition, mental fatigue, and mood state. In this randomized double-blind placebo-controlled study, 60 healthy adults (age 45-64 years) with self-awareness of cognitive decline were randomly divided into 2 groups and received either orally administered MHBAs (35 mg/day) or placebo for 12 weeks. Cognitive functions and mental states were assessed using neuropsychological tests or questionnaires at baseline and weeks 6 and 12 of the intervention. The change in verbal fluency score at week 6 compared with that at baseline was significantly higher in the MHBAs-treated group compared with that in the placebo group (P = 0.034), and Stroop test score at week 12 was significantly lower in the MHBAs-treated group compared with the placebo group (P = 0.019). Furthermore, subjective fatigue and anxiety at week 12 were significantly improved in the MHBAs-treated group (P = 0.008 and 0.043, respectively) compared with the placebo group. This is the first study to evaluate the effects of bitter ingredients in beer on cognition, subjective mood, and mental fatigue in a clinical trial. Our findings suggest that hop-derived bitter acids might be beneficial for cognition and mood state.


Assuntos
Ácidos/metabolismo , Cerveja/análise , Cognição , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/psicologia , Humulus/química , Humulus/metabolismo , Extratos Vegetais/metabolismo , Ácidos/análise , Afeto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
2.
Arch Oral Biol ; 109: 104554, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31563709

RESUMO

OBJECTIVE: Psidium sp., Mangifera sp. and Mentha sp. and its mixture (PEM) are known to have antimicrobial and anti-adherence effects. DESIGN: Here, we have investigated these individual plant extracts and its synergistic mixture (PEM) for its anti-cariogenic effect to reduce populations of single and mixed-species of Streptococcus sanguinis and Streptococcus mutans in a planktonic or/and biofilm and their others reduced virulence. Bacterial populations in the biofilm after 24 h, hydrophobic cell surface activity to n-hexadecane and pH changes at 5 min' intervals until 90 min of incubation were recorded. Total phenolic content and bioactive compounds in the crude aqueous plant extracts were analysed. Regulatory gene expressions of S. mutans adhesins genes (gtfB, gtfC, gbpB and spaP) upon treatment with PEM were investigated in planktonic and biofilm conditions. RESULTS: All plant extracts strongly reduced S. mutans in the biofilm compared to S. sanguinis in single and mixed-species. PEM reduced S. mutans by 84% with S. sanguinis 87% in the mixed population. Psidium sp. and PEM highly reduced cell-surface hydrophobicity of the two bacteria thus reducing adherence and biofilm formation. PEM and Mangifera sp. lowered initial pH change in the mixed populations of S. sanguinis and S. mutans. PEM downregulated the S. mutans gtfB gene expression in the single species planktonic and mixed-species biofilms. CONCLUSIONS: The effectiveness of PEM in reducing S. mutans within the biofilm, cell-surface hydrophobicity, acid production and adhesin gene (gtfB) expression in mixed-species with S. sanguinis indicates its potential as an antibacterial agent against dental caries. This is attributed to the phenolic content in the PEM.


Assuntos
Biofilmes/efeitos dos fármacos , Mangifera/química , Mentha/química , Extratos Vegetais/farmacologia , Psidium/química , Ácidos/análise , Aderência Bacteriana/efeitos dos fármacos , Genes Bacterianos , Concentração de Íons de Hidrogênio , Streptococcus/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos
3.
Environ Sci Pollut Res Int ; 26(33): 34357-34367, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31493079

RESUMO

To investigate the acid-extractable heavy metals in fine particulate matter (PM2.5) over Xi'an, China, 24-h PM2.5 samples were collected every 3 days from December 2015 through November 2016. The bioavailable fraction, termed here the bioavailability index (BI), of PM2.5-bound metal (As, Ba, Cd, Co, Cu, Mn, Ni, Pb, Ti, V, and Zn) and potential influencing factors, including relative humidity, temperature, air pressure, wind speed, visibility, PM2.5, and SO2 concentrations, were assessed in this study. The annual average PM2.5 concentration was 50.6 ± 35.6 µg m-3, 1.5 times higher than the Chinese national secondary standard. Zn, Ti, and As were the most abundant elements of those analyzed in the PM2.5 samples, accounting for 72.1% of total quantity. The seasonal variations and enrichment factor analysis of heavy metals revealed that coal combustion in winter was a crucial source of Pb, Co, Cu, and Zn; and dust resuspension in spring contributed considerable Mn, Ti, and V. The acid-extractable fractions of the measured metals varied. Pb, Cu, Mn, and Zn exhibited relatively high acid-extractable concentrations and BI values. Pb was mostly in the acid-extractable fraction in PM2.5, with a mean BI value of 66.7%, the highest in summer (69.8%) and lowest in winter (63.7%). Moreover, the BIs of PM2.5-bound heavy metals were inversely related to temperature and wind speed, whereas positively correlated with relative humidity, SO2, and PM2.5 concentration in this study. This study assessed the seasonal distribution and meteorological influence of acid-extractable heavy metals, providing a deeper understanding of atmospheric heavy metal pollution in Xi'an, China.


Assuntos
Poluentes Atmosféricos/química , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Metais Pesados/química , Conceitos Meteorológicos , Material Particulado/química , Ácidos/análise , Poluentes Atmosféricos/análise , Disponibilidade Biológica , China , Poeira/análise , Metais Pesados/análise , Meteorologia , Material Particulado/análise , Estações do Ano
4.
Genes (Basel) ; 10(8)2019 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-31405132

RESUMO

We reported changes in the co-regulated mRNA expression in iron walnut (Juglans sigillata) in response to soil pH treatments and identified mRNAs specific to acidic soil conditions. Phenotypic and physiological analyses revealed that iron walnut growth was greater for the pH 4-5 and pH 5-6 treatments than for the pH 3-4 and pH 6-7 treatments. A total of 2768 differentially expressed genes were detected and categorized into 12 clusters by Short Time-series Expression Miner (STEM). The 994 low-expression genes in cluster III and 255 high-expression genes in cluster X were classified as acid-responsive genes on the basis of the relationships between phenotype, physiology, and STEM clustering, and the two gene clusters were analyzed by a maximum likelihood (ML) evolutionary tree with the greatest log likelihood values. No prominent sub-clusters occurred in cluster III, but three occurred in cluster X. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that acid-responsive genes were related primarily to arginine biosynthesis and the arginine/proline metabolism pathway, implying that polyamine accumulation may enhance iron walnut acid stress tolerance. Overall, our results revealed 1249 potentially acid-responsive genes in iron walnut, indicating that its response to acid stress involves different pathways and activated genes.


Assuntos
Genes de Plantas , Juglans/genética , Poliaminas/metabolismo , Estresse Fisiológico , Transcriptoma , Ácidos/análise , Ácidos/farmacologia , Regulação da Expressão Gênica de Plantas , Juglans/efeitos dos fármacos , Juglans/metabolismo , Solo/química
5.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1126-1127: 121708, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31437773

RESUMO

Analysis of acidic pharmaceuticals in complex biological samples is a challenging and formidable task due to the existence of interfering constituents within the sample matrices. Therefore, in order to avoid analytical column clogging and suppression/enhancement of signals of the analyte of interest, herein a simple, cost-effective and quick online ion chromatography based clean-up setup was introduced. This system was further coupled with a cost-effective homemade photochemically induced fluorimetric (PIF) setup for direct online conversion of non-fluorescent acidic pharmaceutical drugs into their respective fluorescent species. This advantageous system was favorably applied for the determination of four non-fluorescent acidic compounds in two complex biological samples (human serum and oral fluid) with minimum labor and organic solvent consumption. At optimized conditions, the developed method has shown good sensitivity, selectivity, satisfactory recoveries (88.68-102.14%) and low limits of detection (0.35-8.10 µg/L) with minimum or zero matrix effect.


Assuntos
Cromatografia por Troca Iônica/métodos , Fluorometria/métodos , Preparações Farmacêuticas/análise , Ácidos/análise , Ácidos/sangue , Ácidos/química , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Modelos Lineares , Preparações Farmacêuticas/sangue , Preparações Farmacêuticas/química , Reprodutibilidade dos Testes , Saliva/química
6.
Artigo em Inglês | MEDLINE | ID: mdl-31364465

RESUMO

This paper presents the results of laboratory investigations conducted on gold mine tailings (GMT) to assess their chemical, mineralogical and geotechnical characteristics in view of assessing its suitability as an alternative backfilling solution in mine reclamation. Chemical characterization revealed that GMT is dominated by Si, Al, and Fe with notable amounts of Cr, Zr, Zn, Pb, Ce, As, Ba, Ni, V, Sr, Nd, Cu, U, and Co. Mineralogical characterization revealed a composition of silicate minerals with secondary minerals such as jarosite, goethite and hematite. GMT composites showed improved strength characteristics. The particle sizes of the tailings are capable of producing a good paste fill that will require lower water-cement ratio. Moreover, the plasticity of the tailings provide for a likelihood for shear resistance to sliding in fluvial conditions. Curing and addition of cement showed positive effects on the compressive strength and shear strength of the tailings. However, the effect of curing and cement addition on the compaction characteristics and permeability of the tailings were negligible. GMT showed favorable characteristics for use in mine backfilling; it would be interesting to evaluate higher cement ratios to improve the characteristics of the tailings.


Assuntos
Ouro/análise , Ácidos/análise , Monitoramento Ambiental/métodos , Compostos Férricos/análise , Compostos de Ferro/análise , Minerais/análise , Mineração , África do Sul , Sulfatos/análise
7.
Res Microbiol ; 170(6-7): 288-295, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31279086

RESUMO

Due to land uplift after the last ice age, previously stable Baltic Sea sulfidic sediments are becoming dry land. When these sediments are drained, the sulfide minerals are exposed to air and can release large amounts of metals and acid into the environment. This can cause severe ecological damage such as fish kills in rivers feeding the northern Baltic Sea. In this study, five sites were investigated for the occurrence of acid sulfate soils and their geochemistry and microbiology was identified. The pH and soil chemistry identified three of the areas as having classical acid sulfate soil characteristics and culture independent identification of 16S rRNA genes identified populations related to acidophilic bacteria capable of catalyzing sulfidic mineral dissolution, including species likely adapted to low temperature. These results were compared to an acid sulfate soil area that had been flooded for ten years and showed that the previously oxidized sulfidic materials had an increased pH compared to the unremediated oxidized layers. In addition, the microbiology of the flooded soil had changed such that alkalinity producing ferric and sulfate reducing reactions had likely occurred. This suggested that flooding of acid sulfate soils mitigates their environmental impact.


Assuntos
Bactérias/metabolismo , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Microbiota/efeitos dos fármacos , Poluentes do Solo/análise , Solo/química , Ácidos/análise , Bactérias/genética , Ferro/análise , Metais/análise , Microbiologia do Solo , Sulfatos/análise , Sulfetos/análise
8.
J Sci Food Agric ; 99(13): 6011-6019, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31216060

RESUMO

BACKGROUND: The growing area has a substantial effect on plants, affecting secondary metabolism. For hops, different authors have studied the effect of growing area on the chemical composition of cones with the aim of verifying and understanding the changes in hop characters. Despite the scant literature the subject receives increasing attention by brewers and hop growers. The present study aimed to characterize, using gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography with ultraviolet detection (HPLC-UV), cones of hop (Humulus lupulus L.) cultivar Cascade. Plant material was obtained from nine different areas of Italy and compared with Cascade samples grown in the United States, Germany and Slovenia. RESULTS: Differences in bitter acids and xanthohumol content were observed. Nevertheless, no correlation between bitter acids and xanthohumol production, on the one hand, and rainfall, temperatures and latitude, on the other hand, were observed in our samples. The Slovenia samples were richer in molecules that confer hoppy, woody and flower notes; USA2 samples were more characterized by woody, earthy, grassy and floral aroma, quite different characters if compared to USA1, which had the lowest presence of grassy aromatic compounds. In the Italian samples, TRENTINO was the genotype most characterized by limonene presence. CONCLUSION: The results of this study are indicative of the importance for hop users to know and characterize hops coming from different growing regions. The study pays special attention to the characterization of the differences in chemical characters of Cascade hop in Italy, where hop cultivation has developed only recently, but is in continuous expansion. © 2019 Society of Chemical Industry.


Assuntos
Humulus/química , Humulus/crescimento & desenvolvimento , Extratos Vegetais/análise , Ácidos/análise , Ácidos/metabolismo , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Flavonoides/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Itália , Odorantes/análise , Extratos Vegetais/metabolismo , Propiofenonas/análise , Propiofenonas/metabolismo , Metabolismo Secundário , Paladar
9.
J Sci Food Agric ; 99(13): 5910-5917, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31228265

RESUMO

BACKGROUND: Colombia is known for its production of fine and aromatic cocoa; however, the lack of homogeneity in the ripeness stage of cocoa fruit affects the final quality of cocoa beans. Therefore, the aim of this work was to identify parameters that can be use as indicators of ripeness in cocoa fruit in order to homogenize the characteristics of raw cocoa used in the production of cocoa-products industry. The parameters evaluated were fruit, seed and pod weight, firmness, color, polar and equatorial diameters of the fruit, seed moisture content, total titratable acidity, pH, and total soluble solids of pulp. RESULTS: Factors such as seed weight, firmness, diameters, total soluble solids, pH, and acidity were affected by the clone factor, whereas seed weight, pH, and total titratable acidity were affected by ripeness stage. CONCLUSION: Identification of indicators of ripeness for cocoa fruit is a complex task due to the influence of the clone on the evolution of the physicochemical characteristics of cocoa fruit during its maturation process. Thus, indicators must be developed for each clone, and at least two parameters among color, pH, and total titratable acidity should be used to determine the ripeness stage of cocoa fruit. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Cacau/química , Sementes/crescimento & desenvolvimento , Ácidos/análise , Cacau/classificação , Cacau/crescimento & desenvolvimento , Chocolate , Colômbia , Cor , Frutas/química , Frutas/classificação , Frutas/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Sementes/química , Sementes/classificação
10.
Electrophoresis ; 40(14): 1779-1786, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31127638

RESUMO

An alternative method for simultaneous baseline separation of α and ß-acids homologues and isomers in hop by CD-MEKC with UV detection was proposed. The optimized background electrolyte was composed of 30 mmol/L sodium tetraborate solution, 45 mmol/L sodium dodecyl sulfate, 20 mmol/L ß-cyclodextrin and 10% v/v acetonitrile. The instrumental conditions were evaluated by using a 33 Box-Benhken experimental design. In order to demonstrate the applicability of the method, 21 hop samples from different varieties were analyzed. The repeatability intra- and interday tests were performed and relative standard deviations lower than 7% for area and migration times were observed. The present method comprehended 8 min analysis time and revealed to be faster and more efficient when compared to previous reports from literature.


Assuntos
Ácidos/análise , Humulus/química , Boratos/química , Cromatografia Capilar Eletrocinética Micelar , Eletroforese Capilar , Isomerismo , Dodecilsulfato de Sódio/química , Espectrofotometria Ultravioleta , beta-Ciclodextrinas/química
11.
Environ Pollut ; 250: 127-136, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30991281

RESUMO

In May 2017, a spill from La Zarza pit lake (SW Spain) resulted in the release of approximately 270,000 m3 of extremely acidic waters to the Odiel River. Around 780 × 103 kg of Fe, 170 × 103 kg of Al, 2.15 × 103 kg of As and high amounts of other trace metals and metalloids were spilled. The purpose of this study is to explain the causes, consequences and impacts of the mine spill on the receiving water bodies. To this end, an extensive sampling along the mine site, river and estuary as well as a hydrological model of the pit lake was performed. Around 53 km of the Odiel River's main course, which was already contaminated by acid mine drainage (AMD), were affected. The mine spill resulted in an incremental impact on the Odiel River water quality. Thus, dissolved concentrations of some elements increased in the river up to 450 times; e.g. 435 mg/L of Fe and 0.41 mg/L of As. Due to low pH values (around 2.5), most metals (e.g., Cu, Zn, Mn, Cd) were transported in the dissolved phase to the estuary, exhibiting a conservative behavior and decreasing their concentration only due to dilution. However, dissolved concentrations of Fe, Cr, Pb, Se, Sb, Ti, V and especially As decreased significantly along the river due to Fe precipitation and sorption/coprecipitation processes. At the upper zone of the estuary, a noticeable increment of metal concentrations (up to 77 times) was also recorded. The water balance illustrates the existence of groundwater inputs (at least 16% of total) to the pit lake, due probably to local infiltration of rainwater at the mining zone. The probable existence of an ancient adit connected to the pit lake indicates that potential releases could occur again if adequate prevention measures are not adopted.


Assuntos
Ácidos/análise , Monitoramento Ambiental/métodos , Lagos/química , Metais/análise , Mineração , Rios/química , Poluentes Químicos da Água/análise , Ácidos/toxicidade , Estuários , Ferro/análise , Espanha , Sulfetos/análise , Qualidade da Água
12.
Microb Ecol ; 78(3): 651-664, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30854582

RESUMO

Microbial communities inhabiting the acid mine drainage (AMD) have been extensively studied, but the microbial communities in the coal mining waste dump that may generate the AMD are still relatively under-explored. In this study, we characterized the microbial communities within these under-explored extreme habitats and compared with those in the downstream AMD creek. In addition, the interplay between the microbiota and the environmental parameters was statistically investigated. A Random Forest ensemble model indicated that pH was the most important environmental parameter influencing microbial community and diversity. Parameters associated with nitrogen cycling were also critical factors, with positive effects on microbial diversity, while S-related parameters had negative effects. The microbial community analysis also indicated that the microbial assemblage was driven by pH. Various taxa were enriched in different pH ranges: Sulfobacillus was the indicator genus in samples with pH < 3 while Acidobacteriaceae-affiliated bacteria prevailed in samples with 3 < pH < 3.5. The detection of some lineages that are seldom reported in mining areas suggested the coal mining dumps may be a reservoir of phylogenetic novelty. For example, potential nitrogen fixers, autotrophs, and heterotrophs may form diverse communities that actively self-perpetuate pyrite dissolution and acidic waste generation, suggesting unique ecological strategies adopted by these innate microorganisms. In addition, co-occurrence network analyses suggest that members of Acidimicrobiales play important roles in interactions with other taxa, especially Fe- and S-oxidizing bacteria such as Sulfobacillus spp.


Assuntos
Bactérias/isolamento & purificação , Sedimentos Geológicos/microbiologia , Microbiota , Águas Residuárias/microbiologia , Ácidos/análise , Ácidos/metabolismo , Bactérias/classificação , Bactérias/genética , Minas de Carvão , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Nitrogênio/metabolismo , Filogenia , Sulfetos/metabolismo , Instalações de Eliminação de Resíduos , Águas Residuárias/análise
13.
Food Chem ; 284: 296-302, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744861

RESUMO

Bio-electronic tongue was linked to artificial intelligence processing unit and used for classification of wines based on carboxylic acids levels, which were indirectly related to malolactic fermentation. The system employed amperometric biosensors with lactate oxidase, sarcosine oxidase, and fumarase/sarcosine oxidase in the three sensing channels. The results were processed using two statistical methods - principal component analysis (PCA) and self-organized maps (SOM) in order to classify 31 wine samples from the South Moravia region in the Czech Republic. Reference assays were carried out using the capillary electrophoresis (CE). The PCA patterns for both CE and biosensor data provided good correspondence in the clusters of samples. The SOM treatment provided a better resolution of the generated patterns of samples compared to PCA, the SOM derived clusters corresponded with the PCA classification only partially. The biosensor/SOM combination offers a novel procedure of wine classification.


Assuntos
Ácidos/análise , Técnicas Biossensoriais/métodos , Vinho/análise , República Tcheca , Técnicas Eletroquímicas , Eletroforese Capilar , Fumarato Hidratase/metabolismo , Oxigenases de Função Mista/metabolismo , Compostos Orgânicos/química , Análise de Componente Principal , Sarcosina Oxidase/metabolismo
14.
Environ Geochem Health ; 41(5): 1909-1921, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30701355

RESUMO

Aljustrel mining area (South Portugal) is a part of the Iberian Pyrite Belt and encloses six sulfide mineral masses. This mine is classified of high environmental risk due to the large tailings' volume and acid mine drainage (AMD)-affected waters generated by sulfides' oxidation. The use of biological indicators (e.g., diatoms) revealed to be an important tool to address the degree of AMD contamination in waters. Multivariate analysis has been used as a relevant approach for the characterization of AMD processes. Cluster analysis was used to integrate the significant amount and diversity of variables (physicochemical and biological), discriminating the different types of waters, characterized by the high complexity occurring in this region. The distinction of two main marked phenomena was achieved: (1) the circumneutral-Na-Cl water type (sites DA, PF, BX, BF, RO, CB), expressing the geological contributions of the Cenozoic sediments of Sado river basin, with high diatom diversity (predominating brackish diatoms as Entomoneis alata); and (2) the acid-metal-sulfated water type (sites BM, JU, RJ, AA, MR, BE, PC, AF), reflecting both the AMD contamination and the dissolution of minerals (e.g., silicates) from the hosting rocks, potentiated by the extremely low pH. This last group of sites showed lower diatom diversity but with typical diatoms from acid- and metal-contaminated waters (e.g., Pinnularia aljustrelica). In addition to these two water types, this hierarchical classification method also allowed to distinguish individual cases in subclusters, for example, treated dams (DC, DD), with alkaline substances (lime/limestone), that changed the physicochemical dynamics of the contaminated waters.


Assuntos
Diatomáceas/fisiologia , Monitoramento Ambiental , Mineração , Rios/química , Poluentes Químicos da Água/análise , Ácidos/análise , Diatomáceas/classificação , Diatomáceas/crescimento & desenvolvimento , Ferro/análise , Metais/análise , Minerais/análise , Portugal , Sulfetos/análise
15.
J Sci Food Agric ; 99(8): 3792-3802, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30666651

RESUMO

BACKGROUND: Large improvements have been realized on the accuracy of the determination of fruit quality. The relevance of the relationship between commonly used quality descriptors and their related chemical contents was here questioned under the influence of water supply reduction and postharvest cold storage. The study relied on three analyses: (1) a correlation table between quality descriptors and compound contents, (2) principal component analysis using the selected variables to see the quality discrimination dictated by treatments; and (3) linear correlation between content and descriptors according to treatments. RESULTS: The results indicate that abiotic parameters applied on mango fruits before or after harvest can affect the relationship between a quality descriptor and the content in compounds it is related to, here between titratable acidity and organic acid content and to a lesser extent between color, represented by hue angle values, and carotenoids, possibly creating bias in the final quality determination. A stronger relation between total soluble solids and total sugar content, were observed under mild abiotic stress. CONCLUSION: Fruit growth and postharvest storage conditions, such as irrigation and cold storage, can influence the actual correspondence between the compounds contents and the descriptors used to estimate fruit quality, particularly for pulp color, sugars and acids. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Armazenamento de Alimentos/métodos , Frutas/química , Mangifera/crescimento & desenvolvimento , Água/análise , Ácidos/análise , Carotenoides/análise , Climatério , Cor , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Mangifera/química , Mangifera/metabolismo , Extratos Vegetais/análise , Controle de Qualidade , Açúcares/análise , Água/metabolismo
16.
Microbiology ; 165(1): 26-36, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30427306

RESUMO

This work describes the response of Lactobacillusvini, a bacterium found as a contaminant in winemaking and fuel ethanol fermentation processes, to acid stress caused by inorganic or weak organic acids. First, we observed for the first time that bacterial cells become resistant to lysis by lysozyme when submitted to acidic stress. Then, the predicted intracellular acidification can be reversed by the presence of arginine, histidine and glutamine. However, these molecules were not able to reverse the effect of resistance to lysis, indicating the independence of these mechanisms. In general, a reduction in the expression of the main genes involved in the synthesis and deposition of material in the cell wall was observed, whereas the genes involved in the reabsorption of this structure showed increased expression. These data suggested that L. vini responds to the acidification of the medium through early entry into the stationary phase, firing two signals for cell wall remodelling and maintenance of intracellular pHin a coordinated way, most probably by alkalization and the proton extrusion process. If this picture is conserved among lactobacilli, it may not only have an impact on research associated with fermentation processes, but also on that associated with probiotic improvement.


Assuntos
Ácidos/metabolismo , Meios de Cultura/química , Lactobacillus/fisiologia , Ácidos/análise , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Meios de Cultura/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Estresse Fisiológico
17.
Appl Microbiol Biotechnol ; 103(2): 995-1005, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30474727

RESUMO

Biological nitrogen fixation (BNF) is an important natural biochemical process converting the inert dinitrogen gas (N2) in the atmosphere to ammonia (NH3) in the N cycle. In this study, the nifH gene was chosen to detect the diazotrophic microorganisms with high-throughput sequencing from five acidic forest soils, including three natural forests and two re-vegetated forests. Soil samples were taken in two seasons (summer and winter) at two depth layers (surface and lower depths). A dataset of 179,600 reads obtained from 20 samples were analyzed to provide the microbial community structure, diversity, abundance, and relationship with physiochemical parameters. Both archaea and bacteria were detected in these samples and diazotrophic bacteria were the dominant members contributing to the biological dinitrogen fixation in the acidic forest soils. Cyanobacteria, Firmicutes, Proteobacteria, Spirocheates, and Verrucomicrobia were observed, especially the Proteobacteria as the most abundant phylum. The core genera were Bradyrhizobium and Methylobacterium from α-Proteobacteia, and Desulfovibrio from δ-Proteobacteia in the phylum of Proteobacteia of these samples. The diversity indices and the gene abundances of all samples were higher in the surface layer than the lower layer. Diversity was apparently higher in re-vegetated forests than the natural forests. Significant positive correlation to the organic matter and nitrogen-related parameters was observed, but there was no significant seasonal variation on the community structure and diversity in these samples between the summer and winter. The application of high-throughput sequencing method provides a better understanding and more comprehensive information of diazotrophs in acidic forest soils than conventional and PCR-based ones.


Assuntos
Archaea/classificação , Bactérias/classificação , Variação Genética , Microbiota , Fixação de Nitrogênio , Oxirredutases/genética , Microbiologia do Solo , Ácidos/análise , Archaea/enzimologia , Archaea/genética , Archaea/metabolismo , Bactérias/enzimologia , Bactérias/genética , Bactérias/metabolismo , Fenômenos Químicos , Florestas , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Estações do Ano , Solo/química
18.
J Sci Food Agric ; 99(1): 25-38, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30246252

RESUMO

Acidic beers, such as Belgian lambic beers and American and other coolship ales, are becoming increasingly popular worldwide thanks to their refreshing acidity and fruity notes. The traditional fermentation used to produce them does not apply pure yeast cultures but relies on spontaneous, environmental inoculation. The fermentation and maturation process is carried out in wooden barrels and can take up to three years. It is characterized by different microbial species belonging to the enterobacteria, acetic acid bacteria, lactic acid bacteria, and yeasts. This review provides an introduction to the technology and four fermentation strategies of beer production, followed by the microbiology of acidic beer production, focusing on the main microorganisms present during the long process used for the production of Belgian lambic beers. © 2018 Society of Chemical Industry.


Assuntos
Ácidos/análise , Álcoois/análise , Bactérias/metabolismo , Cerveja/microbiologia , Aromatizantes/química , Ácidos/metabolismo , Álcoois/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Cerveja/análise , Fermentação , Aromatizantes/metabolismo
19.
Chemosphere ; 219: 695-703, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30557726

RESUMO

A passive treatment plant, located in the Iberian Pyrite Belt (Huelva, Southwest Spain), was designed for acid mine drainage remediation. Since its installation, the improvement of water quality in terms of hydrochemical composition has been demonstrated successfully. However, according to the Water Framework Directive, the treated effluent must have ecological values for potential living. The freshwater clam Corbicula fluminea was chosen to carry out bioassessments (survival, biomarker responses, and metal bioaccumulation in soft tissue) with effluents from the mining site, as well as, products from the passive treatment plant in order to determine the level of quality of that water from the biological point of view in toxicity tests. Results discarded mortality as endpoint for biomonitoring purposes. Only the lipid peroxidation of the cell membrane evidenced significant responses, even in correlation with the pollution degree of each effluent. Regarding bioaccumulation, some elements displayed a strong relationship (Fe, Cu, Co, and Zn) between concentrations in the environment and in the tissue. As final conclusion, the usage of the Asian clam was validated as biomonitor tool in short term exposure to acid mine drainage, and, as early warning responses (72 h), the chosen parameters would be lipid peroxidation and bioaccumulation of a specific set of elements (Fe, Cu, Co, Zn). Ecological water quality levels reached by the passive treatment plant were in agreement with the efficiency of hydrochemical improvements.


Assuntos
Corbicula/química , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental , Mineração , Qualidade da Água , Ácidos/análise , Animais , Bivalves/química , Água Doce/química , Metais Pesados/análise , Espanha , Poluentes Químicos da Água/análise
20.
Zhongguo Zhong Yao Za Zhi ; 43(21): 4240-4247, 2018 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-30583624

RESUMO

The qualitative analysis method of RRLC-Q-TOF-MS/MS was established for determine the chemical constituents in Qige Keli. Kramosil C18 column (4.6 mm×150 mm, 3.5 µm) was used at the temperature of 30 °C. The mobile phase was 0.2% formic acid and acetonitrile by gradient elution, with a flow rate at 1.0 mL·min⁻¹, and the injection volume was 10 µL. The high-resolution quadrupole time-flight mass spectrometry was used as detector with electrospray ion source in both positive and negative models. On the basis of medicinal materials, reference materials, literature reports, and mass spectrometry data, the chemical composition in the Qige Keli was identified. A total of 44 compounds were identified, including 3 flavonoids, 21 flavonoid glycosides, 8 organic acids, 6 lactones, and 3 saponins. The results laid the foundation for the quality control of Qige Keli and the further research on pharmacodynamic materials.


Assuntos
Medicamentos de Ervas Chinesas/química , Compostos Fitoquímicos/análise , Ácidos/análise , Flavonoides/análise , Glicosídeos/análise , Lactonas/análise , Saponinas/análise , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA