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1.
J Agric Food Chem ; 69(15): 4550-4560, 2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33823588

RESUMEN

Coffee cupping includes both aroma and taste, and its evaluation considers several different attributes simultaneously to define flavor quality and therefore requires complementary data from aroma and taste. This study investigates the potential and limits of a data-driven approach to describe the sensory quality of coffee using complementary analytical techniques usually available in routine quality control laboratories. Coffee flavor chemical data from 155 samples were obtained by analyzing volatile (headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS)) and nonvolatile (liquid chromatography-ultraviolet/diode array detector (LC-UV/DAD)) fractions, as well as from sensory data. Chemometric tools were used to explore the data sets, select relevant features, predict sensory scores, and investigate the networks between features. A comparison of the Q model parameter and root-mean-squared error prediction (RMSEP) highlights the variable influence that the nonvolatile fraction has on prediction, showing that it has a higher impact on describing acid, bitter, and woody notes than on flowery and fruity. The data fusion emphasized the aroma contribution to driving sensory perceptions, although the correlative networks highlighted from the volatile and nonvolatile data deserve a thorough investigation to verify the potential of odor-taste integration.


Asunto(s)
Odorantes , Compuestos Orgánicos Volátiles , Café , Cromatografía de Gases y Espectrometría de Masas , Odorantes/análisis , Microextracción en Fase Sólida , Gusto , Compuestos Orgánicos Volátiles/análisis
2.
J Chromatogr A ; 1429: 329-39, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26733393

RESUMEN

Within a project exploring the application of lab-on-chip GC to in-field analysis of the plant volatile fraction, this study evaluated the performance of a set of planar columns (also known as microchannels, MEMS columns, or microfabricated columns) of different dimensions installed in a conventional GC unit. Circular double-spiral-shaped-channel planar columns with different square/rectangular sections up to 2m long were applied to the analysis of both essential oils and headspace samples of a group of medicinal and aromatic plants (chamomile, peppermint, sage, rosemary, lavender and bergamot) and of standard mixtures of related compounds; the results were compared to those obtained with reference narrow-bore columns (l:5m, dc:0.1mm, df:0.1 µm). The above essential oils and headspaces were first analyzed quali-and quantitatively with planar columns statically coated with conventional stationary phases (5%-phenyl-polymethylsiloxane and auto-bondable nitroterephthalic-acid-modified polyethylene glycol), and then submitted to chiral recognition of their diagnostic markers, by enantioselective GC with a planar columns coated with a cyclodextrin derivative (30% 6(I-VII)-O-TBDMS-3(I-VII)-O-ethyl-2(I-VII)-O-ethyl-ß-cyclodextrin in PS-086). Column characteristics and analysis conditions were first optimized to obtain suitable retention and efficiency for the samples investigated. The planar columns tested showed performances close to the reference conventional narrow-bore columns, with theoretical plate numbers per meter (N/m) ranging from 6100 to 7200 for those coated with the conventional stationary phases, and above 5600 for those with the chiral selector.


Asunto(s)
Cromatografía de Gases/instrumentación , Aceites Volátiles/química , Extractos Vegetales/química , Ciclodextrinas/química , Microtecnología , Aceites Volátiles/análisis , Extractos Vegetales/análisis , Aceites de Plantas/química , Siliconas/química , beta-Ciclodextrinas/química
3.
J Chromatogr A ; 985(1-2): 159-66, 2003 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-12580482

RESUMEN

A description is given of a rapid and environmentally friendly method to determine organochlorine and organophosphorus pesticide multiresidues--malathion, methidathion, fenitrothion, fenthion, parathion-ethyl, parathion-methyl, lindane, hexachlorobenzene, chlorothalonil, tetradifon, alpha-endosulfan, beta-endosulfan and dieldrin-in Passiflora alata Dryander and pasiflora edulis Sims. f. flavicarpa Deg. leaves by supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection (HRGC-ECD/FPD). The mild extraction conditions [pure CO2; 100 bar (1 bar = 10(5) Pa) and 40 degrees C (p = 0.62 g/ml); 5 min static+10 min dynamic extraction time; ODS trap and elution with 1 ml n-hexane at 2 ml/min] allow for direct analysis by HRGC-ECD/FPD with no prior cleaning procedure. The method provides. in accordance with the validation criteria of the European Pharmacopoeia, analytical results that are similar or even better than the official procedures, and is simpler, faster and cheaper. Mean recoveries of 69.8-107.1% were obtained, with 1.4-14.7% reproducibility (RSD). The method was applied to analyse commercial samples of Passiflora L. from Brazil. Twenty-three percent of the samples showed the presence of the organochlorine or organophosphorus pesticide residue investigated.


Asunto(s)
Cromatografía de Gases/métodos , Hidrocarburos Clorados , Insecticidas/análisis , Compuestos Organofosforados , Passiflora/química , Residuos de Plaguicidas/análisis , Plantas Medicinales/química , Sensibilidad y Especificidad
4.
J Chromatogr A ; 931(1-2): 129-40, 2001 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-11695515

RESUMEN

Short capillary columns (5 m) with 0.25 mm inner diameter (I.D.) are applied to the GC analysis of medium complexity samples (up to 30 components) with the aim of shortening analysis time. This approach is complementary to fast GC with narrow-bore columns and is based on compensating the lower efficiency of short columns with conventional I.D.'s (0.25-0.32 mm) by using a stationary phase selectivity suitable to separate the components of the sample under investigation, so that the required resolution power is achieved but, at the same time, the analysis time is shortened. The qualitative and quantitative effectiveness of this approach is demonstrated through the analysis of: essential oils with different compositions (chamomile and rosemary), low-volatility triterpenes in a plant extract (Maytenus aquifolium and M. ilicfolium), thermolabile pyrethrins in a Pyrethrum extract, and a mixture of pesticides applied to protect medicinal plant crops. In all examples, GC analysis was five to ten times faster than with conventional columns.


Asunto(s)
Cromatografía de Gases/instrumentación , Aceites Volátiles/análisis , Plaguicidas/análisis , Extractos Vegetales/análisis , Piretrinas/análisis , Reproducibilidad de los Resultados
5.
Phytochem Anal ; 12(4): 255-62, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11705332

RESUMEN

Caper spurge (Euphorbia lathyris L.) seed oil contains a series of diterpenoids known as Euphorbia factors, or L-factors, L1-L9. They are esters of several polyols (lathyrol, epoxylathyrol, hydroxylathyrol and ingenol) and account for about 3-5% of the oil. The percentage of ingenol-based L-factors is very low, less than 5% of the diterpenoid fraction, but some of them (factors L5 and L6) are responsible for the irritant and co-carcinogenic activities of the oil. This paper reports an HPLC-UV and HPLC-positive-ESI-MS analysis of the diterpenoid fraction of caper spurge seed oil before and after selective hydrolysis of ingenol-based L-factors. Separation of lathyrane polyols and esters, and ingenol and its esters was achieved using a chromatographic system consisting of a C18 stationary phase and acetonitrile: water as mobile phase. A new macrocyclic constituent, the deoxy Euphorbia factor L1, was identified in the oil.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Diterpenos/análisis , Euphorbia/química , Fenilpropionatos/análisis , Aceites de Plantas/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrofotometría Ultravioleta/métodos , Sensibilidad y Especificidad
6.
Planta Med ; 67(3): 290-2, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11345708

RESUMEN

The volatile fraction of Tambourissa leptophylla fruit skin was extracted by petrol ether, purified by adsorption chromatography (LPC) and analysed by gas chromatographic-spectroscopic methods. 27 non-oxygenated terpene hydrocarbons and 10 oxygenated derivatives were identified. The most abundant components were: limonene (24.0%), cis-alpha-bergamotene (23.2%), delta-3-carene (8.2%), alpha-curcumene (6.0%), trans-alpha-bergamotene (5.1%), alpha-copaene (4.1%), alpha-pinene (4.0%), p-cymene (4.0%) and bicyclogermacrene (3.3%). The crude volatile fraction was tested in vitro against Cladosporium cucumerinum in direct bioautography on TLC plates on the basis of the antifungal use of fruit skin. Activity of petrol ether extract against this micro-organism was demonstrated.


Asunto(s)
Frutas/química , Lauraceae/química , Terpenos/aislamiento & purificación , Antifúngicos/farmacología , Cromatografía en Capa Delgada , Cladosporium/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Plantas Medicinales/química , Terpenos/química , Terpenos/farmacología , Volatilización
7.
J Chromatogr A ; 892(1-2): 469-85, 2000 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11045505

RESUMEN

Solid-phase microextraction (SPME) is a solvent-free technique, which is well established in headspace analysis since it is sensitive, because of the concentration factor achieved by the fibres, and selective, because of different coating materials which can be used. The performance of eight commercially available SPME fibres was compared to evaluate the recoveries of some characteristic components with different polarities and structures present in the headspace of four aromatic and medicinal plants: rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), thyme (Thymus vulgaris L.) and valerian (Valeriana officinalis L.). The relative concentration capacity of each fibre on the same components of each plant was also determined by comparing their abundance with that obtained by classical static-headspace GC. The partition coefficient, K1, between the headspace gaseous phase and SPME polymeric coating, and the relative concentration factors, of some of the characteristic components of the plant investigated dissolved in dibutyl phtalate, were also determined, under rigorously standardised analysis conditions. The results showed that the most effective fibres were those consisting of two components, i.e., a liquid phase (polydimethylsiloxane) and a porous solid (carboxen or divinylbenzene, or both).


Asunto(s)
Cromatografía de Gases/métodos , Plantas Medicinales/química , Volatilización
8.
Mutat Res ; 281(2): 143-7, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1370983

RESUMEN

The mutagenicity of a series of pyrrolizidine alkaloids, and of extracts from several Italian Senecio species containing pyrrolizidine alkaloids, including S. inaequidens, S. fuchsii and S. cacaliaster, were tested using the Salmonella typhimurium/mammalian microsome system. Retrorsine, senecivernine, seneciphylline and the Senecio extracts showed a weakly mutagenic activity.


Asunto(s)
Mutágenos/toxicidad , Extractos Vegetales/toxicidad , Plantas Tóxicas , Alcaloides de Pirrolicidina/toxicidad , Senecio/química , Animales , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Microsomas Hepáticos/metabolismo , Pruebas de Mutagenicidad , Ratas , Ratas Endogámicas , Salmonella typhimurium/efectos de los fármacos
9.
Planta Med ; 50(1): 96-8, 1984 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17340262

RESUMEN

The essential oil of NEPETA NEPETELLA L. growing in the Aosta Valley (Valnontey), Italy, obtained by steam distillation of the leaves and the flowers, was investigated by capillary gas chromatography in combination with mass spectrometry. To facilitate identification, fractionation of the oil with straight phase HPLC was performed. Nepetalactone (76.5%) is the main component of the oil. The isomers epinepetalactone (0.6%) and neonepetalactone (0.4%) together with the dihydro (1.6%) and dehydro (traces) nepetalactone derivatives were also identified. These compounds are considered to be responsible for the feline attractant activity of NEPETA NEPETELLA L.

10.
Planta Med ; 48(7): 178-80, 1983 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17404981

RESUMEN

By combination of liquid-solid chromatography, capillary GLC and mass spectrometry, the essential oil obtained by steam distillation from the leaves and flowers of ARTEMISIA COERULESCENS L., growing in Tuscany (Poggio di Monselvoli, Siena), was analysed, alpha-Thujone, beta-thujone and camphor accounted for about 69% of the oil which contained more than a hundred compounds, most of which were present only in traces; 36 components were identified.

11.
Planta Med ; 47(1): 49-51, 1983 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17405093

RESUMEN

By combination of capillary GLC and mass spectrometry it was possible to analyze the composition of the essential oil obtained by steam distillation from leaves and flowers of ARTEMISIA ARBORESCENS L. growing in Sassari (Osilo) in Sardinia. This oil is coloured blue by the presence of relatively high amounts (11.32%) of chamazulene, a substance with anti-inflammatory properties. The oil, after separation in fractions on a silica gel column, was investigated by means of capillary GLC and capillary GLC-MS. Thujone, camphor and chamazulene account for about 75% of the oil. Almost a hundred minor components were found by capillary GLC and 44 were identified.

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