RESUMO
Vacuum-Assisted Sorbent Extraction (VASE) is a novel extraction technique that uses vacuum to facilitate the transfer of volatile compounds from the matrix to the sorbent. This technique was explored for extraction of volatiles from cape gooseberry fruit, for both qualitative and quantitative analyses. Selected extraction parameters were tested: sample size, extraction temperature and time, influence of tissue disintegration on release of volatiles, and also addition of Ag+1 ions in the form of AgNO3 to stop enzymatic formation of volatile compounds. For selected conditions (10 g sample, extraction for 30 min. at 40 °C of volatiles from blended fruit) quantitative aspects were explored. Twenty-two compounds of cape gooseberry were tested. The method was characterized with a very good linearity in a range of 10-5000 µg/kg and good reproducibility. The experiments proved the usefulness of VASE in both volatile profiling and quantitative analyses of cape gooseberry and in prospective other fruit.
Assuntos
Frutas , Physalis , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/química , Physalis/química , Frutas/química , Vácuo , Reprodutibilidade dos Testes , Extratos Vegetais/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração em Fase Sólida/métodosRESUMO
BACKGROUND: Myrtle (Myrtus communis L.) is a coastal Mediterranean aromatic medicinal plant rich in essential oil components, flavonoids, and phenolic acids. Studies highlight the potential health benefits of myrtle bioactive compounds with antioxidant and antiproliferative properties. Since limited research exists on myrtle fruit's lipid fraction, the aim of this study was to apply supercritical CO2 extraction to obtain bioactive compounds from myrtle berries focusing on the fatty acids, sterols, and essential oils. METHODS: The optimization of the supercritical CO2 extraction of myrtle fruit using CO2 as solvent was carried out using the response surface methodology with Box-Behnken experimental design. The following conditions were tested: temperature (40, 50, and 60 °C), pressure (200, 300, and 400 bar), and flow rate (20, 30, and 40 g min-1) on the yield of lipid extract as well as on the yield of fatty acids, phytosterols, and volatiles present in the extract and constituting its bioactive potential. RESULTS: In the extracts examined, 36 fatty acids, 7 phytosterols, and 13 volatiles were identified. The average yield of the extract was 5.20%, the most abundant identified fatty acid was essential cis-linolenic acid (76.83%), almost 90% of the total phytosterols were ß-sitosterol (12,465 mg kg-1), while myrtenyl acetate (4297 mg kg-1) was the most represented volatile compound. The optimal process conditions obtained allow the formulation of extracts with specific compositions.
Assuntos
Dióxido de Carbono , Ácidos Graxos , Frutas , Myrtus , Fitosteróis , Fitosteróis/isolamento & purificação , Fitosteróis/química , Fitosteróis/análise , Myrtus/química , Dióxido de Carbono/química , Ácidos Graxos/química , Ácidos Graxos/análise , Ácidos Graxos/isolamento & purificação , Frutas/química , Extratos Vegetais/química , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Cromatografia com Fluido Supercrítico/métodos , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análiseRESUMO
This work used headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze the volatile components of hydrosols of Citrus × aurantium 'Daidai' and Citrus × aurantium L. dried buds (CAVAs and CADBs) by immersion and ultrasound-microwave synergistic-assisted steam distillation. The results show that a total of 106 volatiles were detected in hydrosols, mainly alcohols, alkenes, and esters, and the high content components of hydrosols were linalool, α-terpineol, and trans-geraniol. In terms of variety, the total and unique components of CAVA hydrosols were much higher than those of CADB hydrosols; the relative contents of 13 components of CAVA hydrosols were greater than those of CADB hydrosols, with geranyl acetate up to 15-fold; all hydrosols had a citrus, floral, and woody aroma. From the pretreatment, more volatile components were retained in the immersion; the relative contents of linalool and α-terpineol were increased by the ultrasound-microwave procedure; and the ultrasound-microwave procedure was favorable for the stimulation of the aroma of CAVA hydrosols, but it diminished the aroma of the CADB hydrosols. This study provides theoretical support for in-depth exploration based on the medicine food homology properties of CAVA and for improving the utilization rate of waste resources.
Assuntos
Monoterpenos Acíclicos , Citrus , Monoterpenos Cicloexânicos , Cromatografia Gasosa-Espectrometria de Massas , Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Citrus/química , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Monoterpenos Acíclicos/análise , Monoterpenos Cicloexânicos/análise , Terpenos/análise , Terpenos/química , Monoterpenos/análise , Monoterpenos/isolamento & purificação , Odorantes/análise , Destilação/métodos , AcetatosRESUMO
The monitoring of organic compounds in aquatic matrices poses challenges due to its complexity and time-intensive nature. To address these challenges, we introduce a novel approach utilizing a dual-channel mono (1D) and comprehensive two-dimensional (2D) gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS) system, integrated with a robotic pretreatment platform, for online monitoring of both volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) in water matrices. Employing the robotic platform, we establish a suite of online liquid-liquid extraction (LLE) pretreatment processes for water samples, marking the first instance of such procedures. Leveraging the automatic headspace (HS) module, dual robotic preparations of HS and LLE are sequentially executed to extract VOCs and SVOCs from water matrices. The GC × GC-TOFMS system is distinguished by its dual-channel analytical column configuration, facilitating sequential analysis of VOCs in GC-TOFMS mode and SVOCs in GC × GC-TOFMS mode. Quantitative detection of 55 target VOCs and 104 SVOCs is achieved in a water sample using the instrument system. Our method demonstrates excellent correlation coefficients ranging from 0.990 to 1.000, method detection limits ranging from 0.08 to 4.78 µg L-1, relative standard deviations below 19.3 %, and recovery rates ranging from 50.0 % to 124.0 %. To validate the online monitoring capabilities of our system, we assess target SVOCs at three different concentration levels over a 3-day period. Most compounds exhibit recovery rates ranging from 70.0 % to 130.0 %. Furthermore, we apply our method to analyze a real water sample, successfully identifying over 100 target and nontarget VOCs/SVOCs, including alcohols, aldehydes, ketones, acids, esters, and phenols. These results highlight the efficacy of the proposed analysis system, capable of conducting two distinct analyses in automatic sequence, thereby enhancing the efficiency and accuracy of organic compound analysis in water matrices.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Extração Líquido-Líquido , Robótica , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração Líquido-Líquido/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Limite de DetecçãoRESUMO
The effects of microwave drying (MD), hot air drying (HAD), vacuum hot air drying (VD), and vacuum freeze drying (VFD) on the volatile profiles of Penaeus vannamei were investigated. A total of 89 and 94 volatile compounds were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and monolithic material sorptive extraction gas chromatography-mass spectrometry (MMSE-GC-MS), respectively. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable influence on projection (VIP) models were utilized to select characteristic volatiles and key marker compounds (e.g., octanal, 1-octen-3-ol, 2-methyl-butanal, 2-ethyl-furan, and trimethyl-pyrazine) to discriminate among four drying methods. Based on synthesis of odor descriptions and sensory evaluation, it was found that P. vannamei via MD, HAD, and VD greatly reduced the fishy and generated roasted, fatty, and smoked odors. This study systematically analyzed the aroma characteristics of four traditional dried P. vannamei products, which may provide theoretical guidance for industrial production.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Odorantes , Penaeidae , Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Animais , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Microextração em Fase Sólida/métodos , Odorantes/análise , Penaeidae/química , Humanos , Paladar , Dessecação/métodosRESUMO
More than 40 volatile compounds were detected in sea cucumber powder during the processing (through freeze-dried, desalination, supercritical fluid extraction and ultra-micro grinding) by multiple methods including e-nose, GC-IMS and GC-MS. It has been determined that aldehydes are the predominant volatile substances in the original freeze-dried sample, accounting for about 30 % of the total volatile substances. In addition, we established a supercritical fluid extraction strategy that could efficiently remove the aldehydes from the sea cucumber powder. GC-IMS and GC-MS showed that the relative content of aldehydes significantly decreased by 14 % and 28 %, respectively. Quantification of aldehydes using GC-MS showed a significant decrease in octanal from 927 µg/kg to 159 µg/kg. Further investigation combined with OAV analysis showed that 17 volatile substances in the freeze-dried sea cucumber powder were considered to be the predominant volatile compounds (OAV > 1).The primary fishy compounds found in sea cucumber powder were identified as hexanal, octanal, and an unidentified compound using GC-O, which can be effectively removed (OAV can't been estimated) by the supercritical fluid extraction strategy we established.
Assuntos
Cromatografia com Fluido Supercrítico , Manipulação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Pós , Pepinos-do-Mar , Compostos Orgânicos Voláteis , Cromatografia com Fluido Supercrítico/métodos , Pepinos-do-Mar/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Animais , Manipulação de Alimentos/métodos , Liofilização , Aldeídos/análise , Aldeídos/isolamento & purificação , Nariz Eletrônico , Alimentos Marinhos/análiseRESUMO
The negative impact of lipid peroxidation on health is intimately tied to its oxidation products. In this study, methyl oleate was oxidized at 180â for 0, 2, 4, 8 and 12 h respectively. The free radicals and volatile components generated during the oxidation process were determined using electron spin resonance and headspace solid-phase microextraction (HS-SPME)-GC-MS. The pro-inflammatory effects of oxidized methyl oleate were evaluated in RAW264.7 cells. Then partial least-squares regression (PLSR) models were established for predicting the 3 pro-inflammatory genes expression based on the volatile components. The results revealed that the alkoxy radical content increased rapidly during oxidation from 4 h to 8 h, and the rate of oxidation of methyl oleate dropped after 8 h. A total of 27 volatile oxidation compounds were detected by HS-SPME-GC-MS. The content of most compounds, including aldehydes, esters, and acids, exhibited a pattern of initial increase and then decrease as the oxidation time increased. Similarly, the proinflammatory effects of oxidized methyl oleate peaked after 8 h of oxidation. The PLSR quantitative prediction models showed that the coefficient of determination (R2P) between the predicted and measured values of the 3 inflammatory gene expressions were 0.915, 0.946 and 0.951 respectively. The established PLSR model predicts the pro-inflammatory effects of oxidized methyl oleate well and provides a theoretical foundation for quick evaluation of the pro-inflammatory effects of oxidized lipids.
Assuntos
Ácidos Oleicos , Oxirredução , Camundongos , Animais , Células RAW 264.7 , Peroxidação de Lipídeos , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Radicais Livres , Expressão Gênica/efeitos dos fármacos , Microextração em Fase Sólida , Inflamação/metabolismo , Fatores de Tempo , Análise dos Mínimos QuadradosRESUMO
Symplocarpus foetidus (L.) Salisb. (eastern skunk cabbage) occurs across a broad geographic range of northeastern North America, blooming in winter between December and March. The inflorescences are well-known for their thermogenic and thermoregulatory metabolic capabilities. The perceptual qualities of their fetid floral aroma have been described widely in the literature, but to date the floral volatile composition remained largely unknown. Here we present a detailed study of the floral scent produced by S. foetidus collected from intact female- and male-stage inflorescences and from dissected floral parts. Our results show a large range of biosynthetically diverse volatiles including nitrogen- and sulfur-containing compounds, monoterpenes, benzenoids, and aliphatic esters and alcohols. We document high inter-individual variation with some organ-specific volatile trends but no clear strong variation based on sexual stage. Multivariate data analysis revealed two distinct chemotypes from our study populations that are not defined by sexual stage or population origin. The chemotype differences may explain the bimodal perceptual descriptions in earlier work which vary between highly unpleasant/fetid and pleasant/apple-like. We discuss the results in ecological contexts including potential for floral mimicry, taking into account existing pollination studies for the species. We also discuss the results in evolutionary contexts, comparing our scent data to published scent data from the close sister species Symplocarpus renifolius. Future work should more closely examine the chemotype occurrence and frequency within these and other populations, and the impact these chemotypes may have on pollinator attraction and reproductive success.
Assuntos
Araceae , Flores , Odorantes , Flores/química , Araceae/química , Odorantes/análise , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/análise , PolinizaçãoRESUMO
Plant volatile organic compounds (VOCs) are organic chemicals that plants release as part of their natural biological processes. Various plant tissues produce VOCs, including leaves, stems, flowers, and roots. VOCs are essential in plant communication, defense against pests and pathogens, aroma and flavor, and attracting pollinators. The study of plant volatiles has become an increasingly important area of research in recent years, as scientists have recognized these compounds' important roles in plant physiology. As a result, there has been a growing interest in developing methods for collecting and analyzing plant VOCs. HS-SPME-GC-MS (headspace solid-phase microextraction-gas chromatography-mass spectrometry) is commonly used for plant volatile analysis due to its high sensitivity and selectivity. This chapter describes an efficient method for extracting and identifying volatile compounds by HS-SPME coupled with GC-MS in tomato fruits.
Assuntos
Frutas , Cromatografia Gasosa-Espectrometria de Massas , Solanum lycopersicum , Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Solanum lycopersicum/química , Frutas/química , Compostos Orgânicos Voláteis/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/economia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Sólida/economia , Microextração em Fase Sólida/métodosRESUMO
This study investigated the effect of ultrasound (20-60 min, 40 kHz, 280 W) on the structural, physicochemical, and emulsifying properties of aquafaba extracted from various legumes (chickpea [CH], yellow soybean [YSB], black soybean [BSB], small black bean [SBB]). The hydrophobic amino acids and protein secondary structures (α-helix, random coil) significantly increased with sonication time (p < 0.05). The particle size of aquafaba was reduced by ultrasound (p < 0.05). A total of 27 volatile compounds were identified. Most volatiles increased with sonication time, and beany flavor was lowest in CH and SBB. The EAI, ESI, adsorbed proteins, and zeta-potential increased, while emulsion droplet size decreased in all legumes by ultrasound. The overall emulsifying properties were the highest in SBB sonicated for 40 min. This study discusses the applicability of ultrasound to aquafaba and provides insights into the functional properties and potential of aquafaba as a plant-based natural emulsifier.
Assuntos
Emulsões , Fabaceae , Tamanho da Partícula , Fabaceae/química , Emulsões/química , Emulsificantes/química , Emulsificantes/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , SonicaçãoRESUMO
Bacterial infections cause thousands of deaths in the world every year. In most cases, infections are more serious because the patient is already weakened, and often, the bacteria are already resistant to the antibiotics used. Counterparting this negative scenario, the interest in medicinal plants as an alternative to the synthetic antimicrobial drugs is blossoming worldwide. In the present work, we identified the volatile compounds of ethanol extracts of Melissa officinalis, Mentha sp., Ocimum basilicum, Plectranthus barbatus, and Rosmarinus officinalis by gas chromatography/mass spectrometry (GC/MS). Also was evaluated antimicrobial activity of ethanol extracts against 6 bacteria of clinical interest, and was tested the interaction of these extracts with a commercial antibiotic streptomycin. Phytol was a compound identified in all extracts by GC/MS, being majoritary component in Plectranthus barbatus and Rosmarinus officinalis. The Gram-positive bacteria were more sensitive to ethanol extracts, and Plectranthus barbatus and Rosmarinus officinalis were the most active extracts. Ethanol extracts exhibited a synergetic effect with streptomycin. These results encourage additional studies, in order to evaluate the possibilities of using ethanol extracts of Lamiaceae family as natural source for antibacterial activity.
Assuntos
Humanos , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Sinergismo Farmacológico , Lamiaceae/química , Extratos Vegetais/farmacologia , Estreptomicina/farmacologia , Compostos Orgânicos Voláteis/farmacologia , Antibacterianos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Compostos Orgânicos Voláteis/isolamento & purificaçãoRESUMO
A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GCFID) are described for the analysis of volatile compounds in Tagetes filifolia Lag. The composition of the total aerial parts of the plant (whole plant) and the inflorescences, leaves and stems were studied separately using HS-SPME. As a result, 54 compounds were determined, of which 47 were identified. The major components observed in this analysis were trans-anethole and estragole. The HS-SPME method used for the analysis of volatile compounds of T. filifolia is simple, fast, effective, free from the use of solvents, and permits by an analysis of small amounts of samples to achieve better results in terms of the determination of the composition than those reported in the literature for the analysis of essential oil.
Se realizó el análisis de los componentes volátiles de Tagetes filifolia Lag. utilizando el método de microextracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudio la composición de la planta entera así como también la de las inflorescencias, hojas y tallos por separado empleando el método de HS-SPME. Como resultado, se determinaron 54 compuestos de los cuales 47 fueron identificados. Los componentes mayoritarios observados en este análisis fueron: trans-anetol y estragol. El método de HS-SPME utilizado para el análisis de los compuestos volátiles de T. filifolia es simple, rápido, efectivo, libre de la utilización de solventes, y permitió mediante el análisis de pequeñas cantidades de muestra alcanzar mejores resultados en cuanto a la determinación de la composición, que los reportados en literatura para el análisis del aceite esencial.
Assuntos
Óleos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Plantas Medicinais/química , Tagetes/química , Argentina , Cromatografia Gasosa/métodos , Folhas de Planta/química , Ionização de Chama/métodos , Microextração em Fase Sólida , Caules de Planta/químicaRESUMO
OBJETIVO: Determinar el efecto de los compuestos volátiles en las casas sobre la respuesta conductual del vector del paludismo Anopheles albimanus. MATERIAL Y MÉTODOS: El estudio se realizó en enero de 2006 en el ejido Nueva Independencia, municipio de Suchiate, Chiapas. Se colectaron compuestos volátiles dentro de casas y los extractos se probaron sobre hembras sin alimentar en un olfatómetro en "Y". Los extractos se analizaron mediante cromatografía de gases-espectrometría de masas (CG-EM). RESULTADOS: Se obtuvieron 28 extractos, 12 presentaron respuesta de atracción y dos de repelencia. Los análisis por CG-EM indicaron variación en la presencia de compuestos volátiles y no se vincularon con compuestos específicos indicativos de algún efecto. CONCLUSIONES: Los volátiles en casas presentaron efecto de atracción y repelencia para An. albimanus. No se reconoció un patrón definido en cuanto a la presencia de compuestos químicos característicos y la respuesta obtenida.
OBJECTIVE: To determine effects of volatile compounds in homes on the behavioral response of Anopheles albimanus. MATERIAL AND METHODS: The study was conducted in January 2006, in the village of Nueva Independencia village, Suchiate, Chiapas. Volatile compounds were collected inside homes and the extracts were tested on unfed females in a Y-olfactometer. Extracts were analyzed in a gas chromatography-mass spectrometry system (GC-MS). RESULTS: Twenty eight extracts were obtained, twelve presented attraction and two repellency responses. GC-MS analyses of the extracts indicated variation in the volatile compound present in the extracts, but could not associated specific compounds with any particular effect. CONCLUSIONS: Within homes, volatiles presented attraction and repellency responses to An. albimanus. A definate pattern concerning the presence of a characteristic chemical compound and the observed response was not found.