RESUMO
AIMS: The work investigates the impact of grapes processing at the beginning of winemaking on the composition of microbiota during the oenological fermentations and on the composition of obtained wines. METHODS AND RESULTS: The experiments were conducted in a biodynamic winery to exclude interference due to microbial starters. Three winemaking protocols, with different pre-fermentative management of grapes, were followed by plate count and next generation sequencing on 16S for bacteria and internal transcribed spacer sequencing (ITS) for yeast. Chemical and sensory characterization of wine was performed. The grape processing influenced the evolution of microbiota (especially lactic and acetic acid bacteria) and the fermentation rate. The highest biodiversity was observed in the experiment carried out with whole grapes and carbonic maceration, with the presence of bacterial groups not usually found in winemaking (Bacteroidales, Clostridiales, Oscillospira). The different microbiotas influenced the organic acid profile of wines, the content of biogenic ammines and the perception of organoleptic descriptors linked to the vine cultivar (Syrah). CONCLUSIONS: Carbonic maceration impacts on the evolution of the microbiota and the wine features. The absence of addition of starters and sulphur dioxide would seem to be correlated with the high microbial biodiversity. SIGNIFICANCE AND IMPACT OF THE STUDY: Carbonic maceration is a traditional winemaking practice, today there are difficulties in its managing because the anaerobiosis stimulates spoilage micro-organisms. The work elucidates the reasons of these difficulties and identified some microbial groups rarely associated with winemaking. The ratio of ethanol accumulation along with physical management of grapes and the supply of oxygen during the early stages of winemaking are powerful instruments of oenological variability, able to offer new possibilities to winemakers in order to defining the quality of red wines.
Assuntos
Manipulação de Alimentos/métodos , Microbiota , Vitis/microbiologia , Vinho/microbiologia , Ácidos/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Etanol/análise , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Oxigênio/metabolismo , Vinho/análiseRESUMO
AIMS: Straw wine is a highly valuable oenological production, affected by relevant economical losses due to proliferation of spoilage micro-organisms during drying grapes, after being harvested. In this work, ozone was evaluated as a tool to preserve grapes during drying, in terms of both qualitative and quantitative changes induced in the epiphytic microflora. In addition, the alteration exerted by ozone on grapes' chemical composition was analysed. METHODS AND RESULTS: Grapes from four vine varieties were treated with ozone produced by a cold plasma generator during the entire drying period (6 weeks). The microflora was quantified weekly by plate counts and characterized by 454-pyrosequencing, and was compared with identical, untreated grape samples. At the end of drying, an extensive chemical characterization of the whole mass of grapes by FT-IR and GC-MS was performed. Ozone counteracted the growth of microflora by reducing the microbial population up to 3 log units. From the qualitative point of view, ozone reduced the incidence of spoilage micro-organisms, such as Acetobacter and Botrytis cinerea, among the microbiota of grapes. CONCLUSIONS: The statistical analysis discriminates grape samples based on the residual epiphytic microflora at the end of drying and not on their chemical composition. These evidences confirmed that ozone did control spoilage micro-organisms without altering the volatile profile of grapes. Chemical analysis revealed that untreated grapes are less suitable for winemaking owing to the deprivation of some valuable compounds during the microbial proliferation. SIGNIFICANCE AND IMPACT OF THE STUDY: Ozone is an emerging tool in winemaking, recently applied for controlling spoilage micro-organisms in winery. The present study describes a new application of ozone as an effective and safe alternative to chemical preservatives which are actually involved in the control of microbial alterations of grapes.
Assuntos
Manipulação de Alimentos/métodos , Microbiota/efeitos dos fármacos , Ozônio/farmacologia , Vitis , Vinho , Vitis/química , Vitis/efeitos dos fármacos , Vinho/análise , Vinho/microbiologiaRESUMO
AIMS: We compare the evolution of the microbiota of grapes grown following conventional or biodynamic protocols during the final stage of ripening and wine fermentation in a year characterized by adverse climatic conditions. METHODS AND RESULTS: The observations were made in a vineyard subdivided into two parts, cultivated using a biodynamic and traditional approach in a year which saw a combination of adverse events in terms of weather, creating the conditions for extensive proliferation of vine pests. The biodynamic approach was severely tested, as agrochemicals were not used and vine pests were counteracted with moderate use of copper, sulphur and plant extracts and with intensive use of agronomical practices aimed at improving the health of the vines. Agronomic, microbiological and chemical testing showed that the response of the vineyard cultivated using a biodynamic approach was comparable or better to that of vines cultivated using the conventional method. CONCLUSIONS: The work suggests that biodynamic cultivation of the grapevine may be sustainable even in difficult conditions, representing an interesting alternative to traditional vine-growing approaches. SIGNIFICANCE AND IMPACT OF THE STUDY: This theme is topical and of interest to winemakers and consumers today, but is not easy to study due to the difficulties in finding vineyards with homogeneous characteristics, cultivated using different agronomical protocols. The particular climatic conditions observed in 2014 made this year a rare model, making it possible to verify the applicability of biodynamics to vine growing. The strict experimental plan gave results particularly useful for understanding the features of grape microbiota in a biodynamic context.
Assuntos
Agricultura/métodos , Vitis/crescimento & desenvolvimento , Fermentação , Frutas/crescimento & desenvolvimento , Frutas/microbiologia , Microbiota , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Vitis/microbiologia , Vinho/análise , Vinho/microbiologiaRESUMO
Chemical analyses performed in 2011 on the 575 samples of apples in Trentino (Italy), there are in average 3.24 active ingredient per sample. Moreover, in 98% of the samples with detectable residues, the level did not exceed 30% of the official MRL This result is achieved thanks to the implementation of the guide lines for integrated production by the 8000 fruit growers, to an extension service which justifies the need of the treatment and gives advice on which pesticide fit better for the time-pest combination, to the systematic check up of the sprayers, to the correct sizing of mix volumes to spray according to the size of the canopy, to the selection of active ingredients based on their residual activity in field tests, and to the systematic monitoring of the level of residues found on representative samples of the product at harvest. With these assumptions, the next goal is to eliminate all traces of insecticides and acaricides now present only in 30% of the samples. This aim could be achieved by extending the use of pheromone mating disruption to control fruit feeding Lepidoptera, as well as by promoting the use of short persistent residue products during the final part of the season. Results of some of the experimental field trials are presented and discussed.
Assuntos
Frutas/química , Inseticidas/análise , Malus/química , Resíduos de Praguicidas/análise , Animais , Comportamento Alimentar/efeitos dos fármacos , Frutas/parasitologia , Lepidópteros/efeitos dos fármacos , Lepidópteros/fisiologia , Malus/parasitologia , Controle de PragasRESUMO
The strontium isotope ratio ((87)Sr/(86)Sr) in beef, derived from 206 European cattle, has been measured. These cattle were located in 12 different European regions within France, Germany, Greece, Ireland, Italy, Spain and the UK. As animal protein is known to be a difficult material on which to conduct Sr isotope analysis, several investigations were undertaken to develop and improve the sample preparation procedure. For example, Sr isotope analysis was performed directly on freeze-dried meat and defatted dry mass from the same samples. It was found that enormous differences-sometimes exceeding the measurement uncertainty-could occur between the fractions and also within one sample even if treated in the same manner. These variations cannot be definitely allocated to one cause but are most likely due to inhomogeneities caused by physiological and biochemical processes in the animals as post mortem contamination during analytical processing could be excluded. For further Sr isotope measurements in meat, careful data handling is recommended, and for the authentic beef samples within this project, it was decided to use only freeze-dried material. It can be demonstrated, however, that Sr isotope measurements in beef proteins are a valuable tool for authentication of geographic origin. Although partly overlapping, some of the European sampling sites could be discriminated even by only using (87)Sr/(86)Sr.
Assuntos
Análise de Alimentos/métodos , Contaminação Radioativa de Alimentos/análise , Carne/análise , Isótopos de Estrôncio/análise , Animais , Bovinos , Europa (Continente)RESUMO
Recent understanding of Autism Spectrum Disorder (ASD) showed that peripheral primary mechanosensitive neurons involved in touch sensation and central neurons affected in ASD share transcriptional regulators. Mutant mice for ASD-associated transcription factors exhibit impaired primary tactile perception and restoring those genes specifically in primary sensory neurons rescues some of the anxiety-like behavior and social interaction defects. Interestingly, peripheral mechanosensitive sensory neurons also project to internal organs including the cardiovascular system, and an imbalance of the cardio-vascular sympathovagal regulation is evidenced in ASD and intellectual disability. ASD patients have decreased vagal tone, suggesting dysfunction of sensory neurons involved in cardio-vascular sensing. In light of our previous finding that the ASD-associated Meis2 gene is necessary for normal touch neuron development and function, we investigated here if its inactivation in mouse peripheral sensory neurons also affects cardio-vascular sympathovagal regulation and baroreflex. Combining echocardiography, pharmacological challenge, blood pressure monitoring, and heart rate variability analysis, we found that Meis2 mutant mice exhibited a blunted vagal response independently of any apparent cardiac malformation. These results suggest that defects in primary sensory neurons with mechanosensitive identity could participate in the imbalanced cardio-vascular sympathovagal tone found in ASD patients, reinforcing current hypotheses on the role of primary sensory neurons in the etiology of ASD.
Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Animais , Camundongos , Transtorno do Espectro Autista/genética , Barorreflexo , Frequência Cardíaca , Células Receptoras SensoriaisRESUMO
Alkaloids represent a very large and chemically inhomogeneous group of nitrogen compounds isolated from different natural sources. They have long been studied due to their specific toxicological characteristics, as some of them are suspected of having very dangerous properties, but there has still been little investigation of the existence of possible glycoside precursors in plant products. An analytical method based on a suspect screening approach using liquid chromatography coupled with high resolution tandem mass spectrometry in neutral loss (NL) mode was used for the tentative identification of alkaloid precursors. This NL approach applied to 15 plant extracts made it possible to tentatively identify 41 glycosidic precursors (4 monopentosides, 3 monodeoxyhexosides, 24 monohexosides, 1 pentoside-hexoside and 9 dihexosides) in 6 of them, belonging to the piperidine (21), pyrrolizidine (9), isoquinoline (7), indole (3) and tropane (1) alkaloid groups. This work confirms the promising investigative ability of a suspect screening approach in this complex field of study.
Assuntos
Alcaloides/análise , Técnicas de Química Analítica/métodos , Cromatografia Líquida , Extratos Vegetais/química , Espectrometria de Massas em Tandem , Glicosídeos/análiseRESUMO
Tannins are polyphenolic compounds extensively present in plants and used by food industry as processing aids. Due to the heterogeneity of plant sources, actions involved in food processing and tannin commercial costs can be different. In the last years different approaches aimed at correctly identifying the tannin botanical origin have been developed, in order to satisfy the industry's request to verify product labels. This work aimed to define the glycosidic simple phenolic profile of a large selection of monovarietal commercial tannins of different origin, using a high-resolution untargeted approach. Using accurate mass, isotopic pattern and MS/MS fragmentation, 167 precursors, 89 as monoglycosylated and 78 as diglycosylated derivatives were tentatively identified in tannins, validating the untargeted approach with 3 custom-synthesized glycosidic precursors. Almost all tannin botanical varieties were shown to be characterised by a specific glycosylated phenolic profile, providing possible tools for tannin classification in the case of glycosylphenol standard availability.
Assuntos
Glicosídeos/análise , Espectrometria de Massas em Tandem/métodos , Taninos/análise , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos , Glicosilação , Polifenóis/análise , Polifenóis/química , Taninos/químicaRESUMO
Many metabolites naturally occur as glycosides, since sugar moieties can be crucial for their biological activity and increase their water solubility. In the plant kingdom they may occur as glycosides or sugar esters, depending on precursor chemical structure, and in wine they have traditionally attracted attention due to their organoleptic properties, such as astringency and bitterness, and because they affect the colour and aroma of wines. A new approach directed at detailed description of glycosides in a large selection of monovarietal wines (8 samples each of Pinot Blanc, Muller Thurgau, Riesling, Traminer, Merlot, Pinot Noir and Cabernet Sauvignon) was developed by combining high performance liquid chromatography with high resolution tandem mass spectrometry. Analytical separation was performed on an Accucore™ Polar Premium LC column, while mass analysis was performed in negative ion mode with an non-targeted screening approach, using a Full MS/AIF/NL dd-MS2 experiment at a resolving power of 140,000 FWHM. Over 280 glycoside-like compounds were detected, of which 133 (including low-molecular weight phenols, flavonoids and monoterpenols) were tentatively identified in the form of pentose (6), deoxyhexose (17), hexose (73), hexose-pentose (16), hexose-deoxyhexose (7), dihexose (5) and hexose ester (9) derivatives. It was not possible to univocally define the corresponding chemical structure for the remaining 149 glycosides. Non-parametric statistical analysis showed it was possible to well characterise the glycosylated profile of all red and Traminer wines, while the identified glycosides were almost entirely lacking in Pinot Blanc, Riesling and Muller Thurgau wines. Also Tukey's Honestly Significant Difference test (pâ¯<â¯0.05) and Principal Component Analysis confirmed that it was possible to almost entirely distinguish the selected red wines from each other according to their glycosylated profile.
Assuntos
Glicosídeos/análise , Espectrometria de Massas em Tandem , Vinho/análise , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/química , Flavonoides/análise , Monoterpenos/análise , Odorantes/análise , Fenóis/análise , Análise de Componente PrincipalRESUMO
Free simple phenols have positive effects on health and influence the organoleptic profile of cocoa products, contributing towards defining their aroma and nutritional properties. Glycosidically bound simple phenols can be hydrolysed during the production phase to the corresponding free forms, and thus potentially contribute to the final sensory profile. In this work, 60 samples of Forastero cocoa beans from all over the world were analysed, combining on-line solid phase extraction (SPE) clean-up with ultra-high performance liquid chromatography (UHPLC), coupled with high resolution mass spectrometry. Operating in negative ion mode and with a heated electrospray, 62 simple phenols were measured, of which four were glucosidic precursors, with quantification limits ranging from 0.04 to 40mgkg-1, calibration R2 of 0.99 for over 93% of compounds, and precision (R.S.D.%) always lower than 12%. On the basis of accurate mass, isotope pattern and MS/MS spectrum, 32 monoglycosylated simple phenols such as hexoside and pentoside precursors, and 14 diglycosylated simple phenols such as hexoside-hexoside, hexoside-pentoside and pentoside-hexoside precursors, were tentatively identified. The untargeted approach was validated using 3 glucosidic precursors synthesized by an external supplier. Honestly Significant Difference Tukey's test (p<0.05) and Discriminant Analysis showed it was possible to distinguish the geographical origin of cocoa beans. In particular, the absolute free phenol profile made it possible to characterise 4 out of 5 production macro-areas well, while an untargeted approach based on the ionisation profiles of glycosylated forms allowed complete characterisation of all the 5 macro-areas.
Assuntos
Cacau/química , Glicosilação , Fenóis/análise , Fenóis/química , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão , Glucosídeos/análise , Glucosídeos/química , Glicosídeos/análise , Glicosídeos/química , Extração em Fase SólidaRESUMO
Free simple phenols have a significant role in defining the sensory and nutritional characteristics of wines, affecting the organoleptic profile and having positive effects on health, but glycosidically bound phenols can also be hydrolysed during the winemaking process, releasing the corresponding volatile compounds and making a possible contribution to the final sensory profile. In this work, application of on-line SPE liquid chromatography-high resolution mass spectrometry, operating in negative polarity with heated electrospray, allowed to detect over eighty free and glycosylated simple phenols in Primitivo di Manduria and Negroamaro wines. Sixty-one phenols, four of which phenolic glucosidic precursors, were quantified as having quantification limits ranging from 0.001 to 0.1µgmL(-1), calibration R(2) of 0.99 for over 92% of compounds, and precision (R.S.D.%) always lower than 12%. Twenty-four simple phenolic precursors were tentatively identified as hexoside, pentoside and hexoside-hexoside derivatives, on the basis of accurate mass, isotopic pattern and MS/MS fragmentation.
Assuntos
Fenol/análise , Vinho/análise , Cromatografia Líquida , Análise de Alimentos , Glicosilação , Itália , Reprodutibilidade dos Testes , Espectrometria de Massas em TandemRESUMO
Epidemiology and prognosis of complications related to allogeneic hematopoietic stem cell transplant (HSCT) recipients requiring admission to intensive care unit (ICU) have not been reassessed precisely in the past few years. We performed a retrospective single-center study on 318 consecutive HSCT patients (2009-2013), analyzing outcome and factors prognostic of ICU admission. Among these patients, 73 were admitted to the ICU. In all, 32 patients (40.3%) died in ICU, 46 at hospital discharge (63%) and 61 (83.6%) 1 year later. Survivors had a significantly lower sequential organ failure assessment (SOFA) score, serum lactate and bilirubin upon ICU admission. Catecholamine support, mechanical ventilation (MV) and/or renal replacement therapy during ICU stay, a delayed organ support and an active graft versus host disease (GvHD) significantly worsen the outcome. By multivariate analysis, the worsening of SOFA score from days 1 to 3, the need for MV and the occurrence of an active GvHD were predictive of mortality. In conclusion, the incidence of HSCT-related complications requiring an admission to an ICU was at 22%, with an ICU mortality rate of 44%, and 84% 1 year later. A degradation of SOFA score at day 3 of ICU, need of MV and occurrence of an active GvHD are main predictive factors of mortality.
Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Unidades de Terapia Intensiva , Adulto , Aloenxertos , Intervalo Livre de Doença , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Taxa de SobrevidaRESUMO
Phenolic compounds seriously affect the sensory and nutritional qualities of food products, both through the positive contribution of wood transfer in barrel-aged products and as off-flavours. A new targeted analytical approach combining on-line solid-phase extraction (SPE) clean-up to reduce matrix interference and rapid chromatographic detection performed with ultrahigh-performance liquid chromatography coupled with quadrupole/high-resolution mass spectrometry (Q-Orbitrap), was developed for the quantification of 56 simple phenols. Considering the advantages of using on-line SPE and a resolving power of 140,000, the proposed method was applied to define phenolic content in red (N=8) and white (8) wines, spirits (8), common (8) and balsamic (8) vinegars. The final method was linear from the limits of quantification (0.0001-0.001µgmL(-1)) up to 10µgmL(-1) with R(2) of at least 0.99. Recovery, used to define method accuracy, ranged from 80 to 120% for 89% of compounds. The method was suitable for analytical requirements in the tested matrices being able to analyse 46 phenols in red wines, 41 phenols in white wines and in spirits, 42 phenols in common vinegars and 44 phenols in balsamic vinegars.
Assuntos
Ácido Acético/química , Bebidas Alcoólicas/análise , Cromatografia Líquida , Análise de Alimentos/métodos , Espectrometria de Massas , Extração em Fase Sólida , Vinho/análise , Fenóis/análiseRESUMO
Grape flavonols are involved in the phenomenon of copigmentation in red wines. These compounds are characterised by nutraceutical properties, have antioxidant activity and are studied for chemotaxonomy of grapes. In general, hybrid grapes are characterised by presence of polyphenols often qualitatively and quantitatively different from Vitis vinifera varieties. In this work, flavonols of 34 hybrid grape varieties (22 red and 12 white) produced by crossing of V. vinifera, Vitis riparia, Vitis labrusca, Vitis lincecumii and Vitis rupestris species, were studied. Compounds were characterised by combining different liquid chromatography/mass spectrometry (LC/MS) methods: precursor-ion and neutral-loss multiple-reaction-monitoring (MRM), and high-resolution mass spectrometry. Twenty-four glycoside flavonols were identified, including 4 quercetin, 5 myricetin, 4 kaempferol, 3 isorhamnetin, 2 laricitrin, 3 syringetin and 3 dihydroflavonol derivatives; myricetin hexoside-glucuronide, myricetin O-di-hexoside, syringetin O-di-hexoside, isorhamnetin rutinoside and kaempferol rutinoside were found in grape for the first time. Statistical analysis (PCA and cluster analysis) divided the samples in four groups on the basis of their flavonol profiles.
Assuntos
Flavonóis/química , Extratos Vegetais/química , Vitis/química , Cromatografia Líquida de Alta Pressão/métodos , Frutas/química , Frutas/classificação , Frutas/genética , Espectrometria de Massas/métodos , Vitis/classificação , Vitis/genéticaRESUMO
The anthocyanins of 21 hybrid red varieties produced by crossing V. vinifera, V. riparia, V. labrusca, V. lincecumii and V. rupestris species, the profiles for which have not yet been reported, were studied. Profiles were determined by LC/DAD, and identification of single anthocyanins was confirmed by LC/MS precursor-ion analysis. Anthocyanidin precursors (pelargonidin at m/z 271, dephinidin at m/z 303, cyanidin at m/z 287, petunidin at m/z 317, peonidin at m/z 301, and malvidin at m/z 331) and precursors of monoglucoside compounds allowed 24 different compounds to be identified. Analysis of precursor ions of monoglucoside anthocyanins at low capillary voltage revealed the signals of diglucosides only, providing a very selective method for analysis of diglucoside anthocyanins in grape. According to anthocyanin profile, the samples were subdivided into two groups: one characterized by the substantial presence of diglucoside compounds (particularly Seyve Villard 23-399 and Seyve Villard 23-369) and one by the scarce presence or practical absence of diglucosides (Seibel 10878, Burdin 4077, and Galibert 238-35). Particularly interesting for producing anthocyanin for the natural colorant industry were the varieties Siebel 8357, Bacò 30-12 and Terzi 100-31.
Assuntos
Antocianinas/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Vitis/química , Antocianinas/análiseRESUMO
The paper discusses the (2)H/(1)H, (18)O/(16)O and (13)C/(12)C ratios of 196 authentic Italian extra-virgin olive oils produced in 3 years on the Tyrrhenian and Adriatic coasts. The (2)H/(1)H and (18)O/(16)O ratios were linearly and positively correlated. The year of production influenced mainly (18)O/(16)O in relation to the amount of rainfall and the atmospheric humidity in the period of oil accumulation in the olives. The (2)H/(1)H ratio significantly distinguished the olive oils produced on the Adriatic coast from those on the Tyrrhenian coast in each year. This coast effect is a consequence of the different sources and isotopic compositions of the rainfall and the different climatic conditions on the two coasts. The paper contributes towards understanding the influence of climatic factors on isotopic variability and towards improving the traceability of the geographical origin of olive oils, using (2)H/(1)H as a more innovative parameter.
Assuntos
Isótopos de Carbono/análise , Clima , Hidrogênio/análise , Isótopos de Oxigênio/análise , Óleos de Plantas/análise , Análise de Alimentos , Geografia , Marcação por Isótopo , Itália , Espectrometria de Massas/métodos , Azeite de Oliva , Tempo (Meteorologia)RESUMO
A HPLC method using a coulometric electrode array detector (CEAD) to analyse 4-ethylcatechol in wine was established. The procedure does not require any sample preparation or analyte derivatisation and performs chromatographic separation in a short time. The assay method is linear up to 1520microgL(-1) and precise (R.S.D.<3%), with limits of detection and quantitation of 1.34microgL(-1) and 2.2microgL(-1), respectively. Recoveries in spiked wine samples ranged from 95% to 104% with a median value of 102% and matrix effects were not observed. The method was applied to the evaluation of the concentration of 4-EC in 250 commercial Italian wines. The red wines analysed had median, 75 degrees percentile and maximum values of 37microgL(-1), 89microgL(-1) and 1610microgL(-1), respectively. For Sangiovese-based wines the mean ratios of 4-EP and 4-EG to 4-EC were 3.7:1 and 0.7:1, respectively. The feasibility of a cheaper fluorimetric approach to 4-EC quantification was investigated.
Assuntos
Catecóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Vinho/análise , Eletroquímica , Fenóis/análise , Volatilização , ÁguaAssuntos
Diarreia/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Vipoma/diagnóstico , Adulto , Doença Crônica , Diabetes Mellitus Tipo 2/complicações , Diagnóstico Diferencial , Diarreia/etiologia , Humanos , Masculino , Obesidade/complicações , Neoplasias Pancreáticas/complicações , Vipoma/complicaçõesRESUMO
A new high-performance liquid chromatography method using a coulometric array detector to simultaneously analyse 4-ethylphenol, 4-ethylguaiacol, 4-vinylphenol, and 4-vinylguaiacol in wine was established. This procedure offers important advantages as it does not require sample preparation, with the exception of filtration, and performs chromatographic separation in short time, making control of wine production processes easier. The method is linear up to concentrations of 2000 microg L(-1) and precise (R.S.D.<3%). Limits of detection are low (1-3 microg L(-1)) and suitable for analytical requirements in the oenological field. When compared to gas-chromatography-flame ionisation detection, the proposed method gives similar results with a shorter execution time.