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Volatile organic compound analysis

Jialiang Xu, Huijun Wu, Zhiwei Wang, Fuping Zheng, Xin Lu, Zhenpeng Li, Qing Ren
Chinese rice wine (CRW) is the oldest kind of wine in China and is mainly fermented by wheat Qu and yeast with rice, millet, etc. This gives CRW a unique quality, but the flavor components are complex. Its formation is related to microorganisms, but the link between CRW and microorganisms is poorly understood. Here, we used two kinds of sorghum (JZ22 and JB3, of which JZ22 has a higher tannin content) as the raw materials to brew and determined the structural and functional dynamics of the microbiota by metagenomics and flavor analyses...
March 15, 2018: Scientific Reports
Chao Yang, Yan Qi, Jiayi Zheng, X U Fan, Peixin Liang, Cunjiang Song
Uncontrolled bacterial growth and metabolic activities are responsible for the short shelf life of raw pork. Culture-independent analysis by 16S ribosome cDNA could reveal viable bacteria in raw pork. This study investigated microbial growth and volatile organic compounds of raw pork supplemented with various preservatives. Vacuum-packaged raw pork was stored at 4°C, after soaking in solutions of potassium sorbate, ε-poly-l-lysine, kojic acid (KA), or sodium diacetate, individually. Spoilage of raw pork was monitored by determining pH and total volatile basic nitrogen, whereas bacterial growth was determined by culture-dependent and culture-independent analyses...
March 15, 2018: Journal of Food Protection
Ariel Fontana, Isaac Rodríguez, Rafael Cela
The suitability of dispersive liquid-liquid microextraction (DLLME) and gas chromatography accurate mass spectrometry (GC-MS), based on a time-of-flight (TOF) MS analyzer and using electron ionization (EI), for the characterization of volatile and semi-volatile profiles of grape marc distillates (grappa) are evaluated. DLLME conditions are optimized with a selection of compounds, from different chemical families, present in the distillate spirit. Under final working conditions, 2.5 mL of sample and 0.5 mL of organic solvents are consumed in the sample preparation process...
March 3, 2018: Journal of Chromatography. A
Oscar van Mastrigt, Tjakko Abee, Søren K Lillevang, Eddy J Smid
During food fermentation processes like cheese ripening, lactic acid bacteria (LAB) encounter long periods of nutrient limitation leading to slow growth. Particular LAB survive these periods while still contributing to flavour formation in the fermented product. In this study the dairy Lactococcus lactis biovar diacetylactis FM03-V1 is grown in retentostat cultures to study its physiology and aroma formation capacity at near-zero growth rates. During the cultivations, the growth rate decreased from 0.025 h-1 to less than 0...
August 2018: Food Microbiology
Anja Püschel, Rasmus Ebel, Patricia Fuchs, Janet Hofmann, Jochen K Schubert, Jan P Roesner, Stefan Bergt, Andreas Wree, Brigitte Vollmar, Ernst Klar, Carsten M Bünger, Sabine Kischkel
BACKROUND: Paraplegia due to spinal cord ischemia (SCI) is a serious complication after repair of thoraco-abdominal aortic aneurysms. For prevention and early treatment of spinal ischemia intraoperative monitoring of spinal cord integrity is essential. This study was intended to improve recognition of SCI through a combination of transcranial motor-evoked potentials (tc-MEPs), serum markers and innovative breath analysis. METHODS: In nine female German landrace pigs, tc-MEPs were captured, markers of neuronal damage were determined in blood and volatile organic compounds (VOCs) were analysed in exhaled air...
March 5, 2018: Annals of Vascular Surgery
Bo Han, Ya-Ting Liu, Jian-Hui Wu, Yin-Chang Feng
Samples were collected from six different organized industrial odor sources in Tianjin Binhai New Area, including pharmacy, paint spraying, oil refinery, petrochemical, resin synthesis, and rubber manufacturing. Chemical analysis was conducted to identify and quantify major odorous volatile organic compounds (VOCs) and subsequently, establish source profiles. Olfactory measurement was used to characterize the sensory stimulating intensity of odorous VOCs and express them as odor concentration. The TVOC mass concentrations of these six sources were between 10...
March 7, 2018: Environmental Science and Pollution Research International
Emily J Wasserman, Samantha M Reilly, Reema Goel, Jonathan Foulds, John P Richie, Joshua E Muscat
BACKGROUND: Increased cigarette costs have inadvertently strengthened the appeal of discounted brands to price-sensitive smokers. While smokers perceive discounted brands as having poorer quality, little is known about their delivery of toxic tobacco smoke constituents compared to premium-branded tobacco products. METHODS: We investigated the differences between discount and premium brand smokers using the National Health and Nutrition Examination Survey (NHANES) 2011-2012 Special Smoker Sample...
March 6, 2018: Cancer Epidemiology, Biomarkers & Prevention
Mark L Rubinstein, Kevin Delucchi, Neal L Benowitz, Danielle E Ramo
BACKGROUND: There is an urgent need to understand the safety of e-cigarettes with adolescents. We sought to identify the presence of chemical toxicants associated with e-cigarette use among adolescents. METHODS: Adolescent e-cigarette users (≥1 use within the past 30 days, ≥10 lifetime e-cigarette use episodes) were divided into e-cigarette-only users (no cigarettes in the past 30 days, urine 4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol [NNAL] level <1 pg/mL of creatinine; n = 67), dual users (use of cigarettes in the past 30 days in addition to e-cigarettes, NNAL level >30 pg/mL; n = 16), and never-using controls ( N = 20)...
March 5, 2018: Pediatrics
Ian G M Anthony, Matthew R Brantley, Christina A Gaw, Adam R Floyd, Touradj Solouki
For wide class characterizations of volatile organic compounds (VOCs), conventional gas chromatography mass spectrometry (GC-MS)-based techniques are utilized. These GC-MS-based chemical identification approaches typically rely on library searches against ion fragmentation patterns of known compounds. Although MS library searches can often provide correct chemical identities, erroneous chemical assignments of structurally similar unknown compounds are also possible. Other detection systems, such as absorption spectrometers, have been used for VOC analysis and can provide complementary absorption data...
March 5, 2018: Analytical Chemistry
Guillermo Suarez-Cuartin, Jordi Giner, José Luis Merino, Ana Rodrigo-Troyano, Anna Feliu, Lidia Perea, Ferran Sanchez-Reus, Diego Castillo, Vicente Plaza, James D Chalmers, Oriol Sibila
RATIONALE: Airway colonization by Potentially Pathogenic Microorganisms (PPM) in bronchiectasis is associated with worse clinical outcomes. The electronic nose is a non-invasive technology capable of distinguishing volatile organic compounds (VOC) in exhaled breath. We aim to explore if an electronic nose can reliably discriminate airway bacterial colonization in patients with bronchiectasis. METHODS: Seventy-three clinically stable bronchiectasis patients were included...
March 2018: Respiratory Medicine
Wonbin Song, Jong-Kwon Lee, Mi Sic Gong, Kwang Heo, Woo-Jae Chung, Byung Yang Lee
We demonstrate a controllable and reliable process for manifesting color patterns on solid substrates using cellulose nanocrystals (CNCs) without the use of any other chemical pigments. The color can be controlled by adjusting the assembling condition of the CNC solution during a dip-and-pull process while aiding the close-packing of CNCs on the solid surface with the help of ionic liquid (1-butyl-3-methylimidazolium) molecules that screen the repelling electrostatic charge between the CNCs. By controlling the pulling speed from 3 to 9 mm/min during the dip-and-pull process, we were able to control the film thickness from 100 to 300 nm, resulting in films with different colors in the visible range...
March 2, 2018: ACS Applied Materials & Interfaces
Surajit Debnath
Background: Coliforms colonize in dental plaques via oral route and may lead to systemic complications. Escherichia coli and its lipopolysaccharide-induced periodontitis is an emerging threat. Clinical management necessitates antibiotic regimens with risk of resistance and upsetting the gut. There is urgent need for better, sustainable, and economical alternative. Aim: To investigate the inhibition of coliforms, a potential periodontopathogen directly by Indian domestic curd (IDC) " in situ "...
September 2017: Journal of Indian Society of Periodontology
Matthias Eder, Isabelle Sanchez, Claire Brice, Carole Camarasa, Jean-Luc Legras, Sylvie Dequin
BACKGROUND: The volatile metabolites produced by Saccharomyces cerevisiae during alcoholic fermentation, which are mainly esters, higher alcohols and organic acids, play a vital role in the quality and perception of fermented beverages, such as wine. Although the metabolic pathways and genes behind yeast fermentative aroma formation are well described, little is known about the genetic mechanisms underlying variations between strains in the production of these aroma compounds. To increase our knowledge about the links between genetic variation and volatile production, we performed quantitative trait locus (QTL) mapping using 130 F2-meiotic segregants from two S...
March 1, 2018: BMC Genomics
Clemens Ager, Karl Unterkofler, Paweł Mochalski, Susanne Teschl, Gerald Teschl, Christopher A Mayhew, Julian King
In a recent paper K.Unterkofler et al. (JBR 9 (2015), no. 3, 036002) we presented a simple two compartment model which describes &#13; the influence of inhaled concentrations on exhaled breath concentrations for volatile organic compounds (VOCs) with small Henry constants.&#13; &#13; In this paper we extend this investigation concerning the influence of inhaled concentrations on exhaled breath concentrations for VOCs with higher Henry constants.&#13; &#13; To this end we extend our model with an additional compartment which takes into account the influence of the upper airways &#13; on exhaled breath VOC concentrations...
February 28, 2018: Journal of Breath Research
Daniel Johannes Cornelis Berkhout, Hendrik Johannes Niemarkt, Nanne Klaas de Boer, Marc Alexander Benninga, Timotheüs Gualtherus Jacob de Meij
Although the exact pathophysiological mechanisms of both necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in preterm infants are yet to be elucidated, evidence is emerging that the gut microbiota plays a key role in their pathophysiology. Areas covered: In this review, initial microbial colonization and factors influencing microbiota composition are discussed. For both NEC and LOS, an overview of studies investigating preclinical alterations in gut microbiota composition and fecal volatile organic compounds (VOCs) is provided...
February 28, 2018: Expert Review of Gastroenterology & Hepatology
Johannes Luis González, Albert Pell, Montserrat López-Mesas, Manuel Valiente
The use of human teeth as biomarkers has been previously applied to characterize environmental exposure mainly to metal contamination. Difficulties arise when the contaminants are volatile or its concentration level is very low. This study presents the development of a methodology based on the transport through hollow fibre membrane liquid-phase microextraction (HF-LPME), followed by HPLC-UV measurement, to determine three different metabolites of BTEX contaminants, mandelic acid (MA), hyppuric acid (HA), and methylhippuric acid (4mHA)...
February 23, 2018: Science of the Total Environment
Jihong Zhang, Li Zeng, Shaoyang Chen, Helong Sun, Shuang Ma
Salinity stress can impede development and plant growth adversely. However, there is very little molecular information on NaCl resistance and volatile emissions in Lycopersicum esculentum. In order to investigate the effects of salt stress on the release of volatile compounds, we quantified and compared transcriptome changes by RNA-Seq analysis and volatile constituents with gas chromatography/mass spectrometry (GC/MS) coupled with solid-phase microextraction (SPME) after exposure to continuous salt stress...
February 17, 2018: Plant Physiology and Biochemistry: PPB
Cyriac Abby Philips, Rajaguru Paramaguru, Adarsh K Joy, K L Antony, Philip Augustine
INTRODUCTION: Ayurvedic and herbal medicines (AHM) are known to cause varying degrees of drug-induced liver injury (DILI). Clinical, biochemical, histological spectrum and outcomes of AHM linked to severe DILI are not well studied. METHODS: Out of 1440 liver disease patients, 94 were found to have a severe liver injury and associated AHM intake. Thirty-three patients were suspected to have AHM-DILI on Roussel Uclaf Causality Assessment Scoring Method. Forty-seven and 30 of retrieved AHM samples were analyzed for heavy metals and hepatotoxic volatile organic compounds (hVOCs), respectively...
February 24, 2018: Indian Journal of Gastroenterology: Official Journal of the Indian Society of Gastroenterology
Alessia Demichelis, Céline Pascale, Maricarmen Lecuna, Bernhard Niederhauser, Guido Sassi, Maria Paola Sassi
Volatile organic compounds (VOCs) in gas mixtures at trace level (nmol/mol) are routinely measured by chemical and biochemical laboratories as climate indicators, indoor air quality pollutants from building materials emissions, contaminants in food and beverages, and biomarkers in body fluids (blood, urine, breath) of occupational exposure or human diseases. Current analytical instruments used for measurements are gas chromatographs equipped with various injector and detector configurations. The assurance of measurement quality is done by using a huge amount of certified liquid VOC standard solutions (or gaseous VOC standard cylinders) with multiple dilutions to reach the required trace level...
February 22, 2018: Analytical and Bioanalytical Chemistry
Fateme Dehghani, Fariborz Omidi, Omidreza Heravizadeh, Saied Barati Chamgordani, Vahid Gharibi, Akbar Sotoudeh Manesh
In this study, cancer and non-cancer risks of exposure to Volatile Organic Compounds (VOCs) in the coke production unit of a steel plant were evaluated. To determine individual exposure to benzene, toluene, xylene, and ethylbenzene (BTEX), personal samples were taken from the breathing zone of workers according to the National Institute for Occupational Safety and Health (NIOSH) 1501. Cancer and non-cancer risk assessment was performed, using United States Environmental Protection Agency (US EPA) methods. Samples analysis showed that concentration of benzene in the energy and biochemistry and benzol refinement sections was higher than occupational exposure limits (OELs)...
February 21, 2018: International Journal of Occupational Safety and Ergonomics: JOSE
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