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1.
Oxf Med Case Reports ; 2023(12): omad117, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38145268

ABSTRACT

A prolonged stay on the ground after acute carbon monoxide poisoning (COP) is a high-risk situation for venous thromboembolism (VTE), but unusual-site venous thrombosis is rare in this setting. An 81-year-old woman with no personal or family history of VTE who lied on the ground for several hours following massive COP had painful and oedematous temples, so a Doppler ultrasound was prompted and revealed a bilateral superficial temporal vein (STV) thrombosis. There was no heart failure, trauma, inflammatory disease, infection, or vascular malformation. The thrombosis regressed on fondaparinux 2.5 mg given as a daily subcutaneous injection for 45 days. Our observation emphasizes the need to look not only for arteritis but also for venous thrombosis before any temporal pain. STV thrombosis has been reported four times to date. We report the first case of bilateral STV thrombosis in the setting of massive COP and prolonged immobilisation in an elderly patient.

2.
Foods ; 12(24)2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38137289

ABSTRACT

Interest in Metschnikowia (M.) pulcherrima is growing in the world of winemaking. M. pulcherrima is used both to protect musts from microbial spoilage and to modulate the aromatic profile of wines. Here, we describe the isolation, characterization, and use of an autochthonous strain of M. pulcherrima in the vinification of Chasselas musts from the 2022 vintage. M. pulcherrima was used in co-fermentation with Saccharomyces cerevisiae at both laboratory and experimental cellar scales. Our results showed that M. pulcherrima does not ferment sugars but has high metabolic activity, as detected by flow cytometry. Furthermore, sensory analysis showed that M. pulcherrima contributed slightly to the aromatic profile when compared to the control vinifications. The overall results suggest that our bioprospecting strategy can guide the selection of microorganisms that can be effectively used in the winemaking process.

3.
Front Microbiol ; 14: 1252973, 2023.
Article in English | MEDLINE | ID: mdl-37664122

ABSTRACT

Finding alternatives to the use of chemical inputs to preserve the sanitary and organoleptic quality of food and beverages is essential to meet public health requirements and consumer preferences. In oenology, numerous manufacturers already offer a diverse range of bio-protection yeasts to protect must against microbiological alterations and therefore limit or eliminate sulphites during winemaking. Bio-protection involves selecting non-Saccharomyces yeasts belonging to different genera and species to induce negative interactions with indigenous microorganisms, thereby limiting their development and their impact on the matrix. Although the effectiveness of bio-protection in the winemaking industry has been reported in numerous journals, the underlying mechanisms are not yet well understood. The aim of this review is to examine the current state of the art of field trials and laboratory studies that demonstrate the effects of using yeasts for bio-protection, as well as the interaction mechanisms that may be responsible for these effects. It focuses on the yeast Metschnikowia pulcherrima, particularly recommended for the bio-protection of grape musts.

4.
ACS Omega ; 8(17): 15323-15333, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37151522

ABSTRACT

During spirit beverages production, the distillate is divided into three parts: the head, the heart, and the tail. Acetaldehyde and ethanol are two key markers which allow the correct separation of distillate. Being toxic, the elimination of the head part, which contains a high concentration of acetaldehyde, is crucial to guarantee the consumer's health and security. Plus, the tail should be separated from the heart based on ethanol concentration. Nowadays, online or in-line sensors for acetaldehyde monitoring during distillation do not exist, and the online sensors for alcohol monitoring, based on density measurement, remain expensive for producers. In this work, we demonstrate the development of distillation monitoring sensors based on electrical impedance spectroscopy (EIS) measurements, combined with PLS-R (partial least-squares regression) modeling. Four types of sensors are proposed and tested with wine-based distillates. Using PLS-R, the best correlations were found for one electrode, named "SpotsSym". With an R 2 up to 89.9% for acetaldehyde concentration prediction and an R 2 up to 86.8% for ethanol, the obtained results indicate the promising potential of the proposed approach. To our knowledge, this is the first report of sensors capable of simultaneously measuring ethanol and acetaldehyde concentrations. Furthermore, these sensors offer the advantages of being low cost and nondestructive. Based on these results, the development of an in-line distillation monitoring system is possible in the near future, providing a promising tool for spirit beverages producers.

5.
Molecules ; 26(5)2021 Feb 25.
Article in English | MEDLINE | ID: mdl-33669129

ABSTRACT

Often blamed for bringing green aromas and astringency to wines, the use of stems is also empirically known to improve the aromatic complexity and freshness of some wines. Although applied in different wine-growing regions, stems use remains mainly experimental at a cellar level. Few studies have specifically focused on the compounds extracted from stems during fermentation and maceration and their potential impact on the must and wine matrices. We identified current knowledge on stem chemical composition and inventoried the compounds likely to be released during maceration to consider their theoretical impact. In addition, we investigated existing studies that examined the impact of either single stems or whole clusters on the wine quality. Many parameters influence stems' effect on the wine, especially grape variety, stem state, how stems are incorporated, when they are added, and contact duration. Other rarely considered factors may also have an impact, including vintage and ripening conditions, which could affect the lignification of the stem.


Subject(s)
Food Quality , Plant Stems/chemistry , Polyphenols/analysis , Vitis/chemistry , Wine/analysis , Wine/standards , Fermentation , Plant Stems/metabolism , Polyphenols/metabolism , Vitis/metabolism
6.
J Food Sci Technol ; 57(2): 435-443, 2020 Feb.
Article in English | MEDLINE | ID: mdl-32116353

ABSTRACT

Reintegration of grape stem, a by-product from wine production, into the food chain is of high interest from an economic and environmental perspective. Therefore, an investigation of stems was undertaken and is described here. It is known that quality of stems is of high variability. In this study the stems from four grapevine varieties (Syrah, Cabernet Sauvignon, Merlot and Chasselas) cultivated in Switzerland were treated in following ways: drying, cutting and separation into fractions based on particle size. All fractions were then characterised for their phenolic compounds content. It was found that Chasselas fractions contained most phenolic compounds. The addition of grape stems of the four different varieties allowed reduction of the protein content of a model wine. The extent of protein precipitation was highly correlated with the amount of phenolic compounds in stems added. Among the examined varieties, Chasselas brought most promising results, with the high reduction of the protein at low level of stem addition.

7.
Food Chem ; 303: 125405, 2020 Jan 15.
Article in English | MEDLINE | ID: mdl-31466029

ABSTRACT

The study aimed at evaluating the influence of fermented sugarcane molasses ageing on lees and the distillation process used for the production of rums. Molasses were freshly fermented or 3-months lees aged. Batch (PS: Pot Still) or continuous (CS: Coffey Still) distillation was carried out resulting in four different rum distillates. Gas chromatography and 3D-fluorescence enabled to differentiate rum distillates chemical composition according to the distillation process, regardless of the ageing on lees of fermented molasses. Differences in fluorescent PARAFAC components and volatile acids, acetals and carbonyls contents revealed the predominance of the physicochemical processes driven at the liquid-vapor interface of fermented molasses, generated by the distillation systems. Notwithstanding the distilling conditions, the long chain fatty ester content was significantly higher in the 3-months lees aged condition. Multivariate analysis highlighted that CS rum distillates were chemically more homogeneous than those obtained by PS that preserved the lees effect.


Subject(s)
Alcoholic Beverages/analysis , Distillation/methods , Food Handling/methods , Molasses/analysis , Saccharum/chemistry , Chromatography, Gas , Fermentation , Time Factors
8.
PLoS One ; 13(11): e0207218, 2018.
Article in English | MEDLINE | ID: mdl-30408135

ABSTRACT

Thrombotic manifestations are a hallmark of many auto-immune diseases (AID), specially of warm autoimmune hemolytic anemia (wAIHA), as 15 to 33% of adults with wAIHA experience venous thromboembolic events (VTE). However, beyond the presence of positive antiphospholipid antibodies and splenectomy, risk factors for developing a VTE during wAIHA have not been clearly identified. The aim of this retrospective study was to characterize VTEs during wAIHA and to identify risk factors for VTE. Forty-eight patients with wAIHA were included, among whom 26 (54%) had secondary wAIHA. Eleven (23%) patients presented at least one VTE, that occurred during an active phase of the disease for 10/11 patients (90%). The frequency of VTE was not different between primary and secondary AIHA (23.7 vs. 19.2%; p = 0.5). The Padua prediction score based on traditional risk factors was not different between patients with and without VTE. On multivariate analysis, total bilirubin ≥ 40 µmol/L [odds ratio (OR) = 7.4; p = 0.02] and leucocyte count above 7x10(9)/L (OR = 15.7; p = 0.02) were significantly associated with a higher risk of thrombosis. Antiphospholipid antibodies were screened in 9 out the 11 patients who presented a VTE and were negative. Thus, the frequency of VTE is high (23%) during wAIHA and VTE preferentially occur within the first weeks of diagnosis. As no clinically relevant predictive factors of VTE could be identified, the systematic use of a prophylactic anticoagulation should be recommended in case of active hemolysis and its maintenance after hospital discharge should be considered. The benefit of a systematic screening for VTE and its procedure remain to be determined.


Subject(s)
Anemia, Hemolytic, Autoimmune/complications , Venous Thromboembolism/etiology , Adult , Aged , Anemia, Hemolytic, Autoimmune/blood , Anemia, Hemolytic, Autoimmune/therapy , Anticoagulants/therapeutic use , Bilirubin/blood , Female , Humans , Leukocyte Count , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Risk Factors , Venous Thromboembolism/blood , Venous Thromboembolism/prevention & control
9.
Food Chem ; 213: 813-817, 2016 Dec 15.
Article in English | MEDLINE | ID: mdl-27451252

ABSTRACT

The concentrations of α/ß-thujone and the bitter components of Artemisia absinthium were quantified from alcoholic wormwood extracts during four phenological stages of their harvest period. A solid-phase micro-extraction method coupled to gas chromatography-mass spectrometry was used to determine the concentration of the two isomeric forms of thujone. In parallel, the combination of ultra-high pressure liquid chromatography and high resolution mass spectrometry allowed to quantify the compounds absinthin, artemisetin and dihydro-epi-deoxyarteannuin B. This present study aimed at helping absinthe producers to determine the best harvesting period.


Subject(s)
Absinthe/analysis , Artemisia absinthium/chemistry , Monoterpenes/analysis , Taste , Bicyclic Monoterpenes , Chromatography, High Pressure Liquid , Food Handling , Food Quality , Gas Chromatography-Mass Spectrometry , Mass Spectrometry , Plant Extracts/analysis , Reproducibility of Results , Sesquiterpenes, Guaiane/analysis , Solid Phase Extraction
10.
Food Chem ; 211: 957-62, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27283717

ABSTRACT

Understanding how wines react towards oxidation is of primary importance. Here, a novel approach was developed based on the quantitative determination of the key intermediate H2O2 produced during accelerated oxidation by ambient oxygen. The assay makes use of the conversion of the non-fluorescent Amplex Red substrate into a fluorescent product in presence of H2O2. The total production of H2O2 during 30min was quantified with low within-day and between-day variabilities. Polymerized pigments, but not total polyphenols, played a major role in the determination of H2O2 levels, which were lower in white wines than red wines. H2O2 amounts also increased with temperature and the addition of metal ions, but did not depend on the concentration of many other wine constituents such as SO2. H2O2 levels did not correlate with anti-oxidant properties. We believe that this novel methodology might be generically used to decipher the oxidation mechanisms in wines and food products.


Subject(s)
Anthocyanins/analysis , Hydrogen Peroxide/chemistry , Polyphenols/analysis , Wine/analysis , Oxidation-Reduction
11.
Anal Chim Acta ; 732: 114-9, 2012 Jun 30.
Article in English | MEDLINE | ID: mdl-22688042

ABSTRACT

This paper reports on the development of an optimized method for the simultaneous analysis of eight biogenic amines (histamine, methylamine, ethylamine, tyramine, putrescine, cadaverine, phenethylamine, and isoamylamine). The analytical method thus proposed has the following advantages: the easy derivatization of wine, the quantification of biogenic amines and a complete degradation of excess derivatization reagent during sample preparation in order to preserve the column. It consists in reversed phase separation by HPLC and UV-vis detection of the aminoenones formed by the reaction of amino compounds with the derivatization reagent diethyl ethoxymethylenemalonate (DEEMM). The usefulness of this technique was confirmed by an alternative oenological analytical method for the validation, quality control and uncertainty assessment (OIV Oeno 10/2005). The method was validated and proposed as a reference method to the International Organization of Vine and Wine (OIV). As a specific application of the proposed method, the biogenic amine content of Rhône valley wines was investigated.


Subject(s)
Biogenic Amines/analysis , Chromatography, High Pressure Liquid , Histamine/analysis , Wine/analysis , Biogenic Amines/standards , Chromatography, High Pressure Liquid/standards , Histamine/standards , Malonates/chemistry , Quality Control , Temperature , Time Factors
12.
J Agric Food Chem ; 58(18): 10209-18, 2010 Sep 22.
Article in English | MEDLINE | ID: mdl-20799706

ABSTRACT

High temperatures (typically 80 °C) are widely used to assess wine stability with regard to protein haze or to study mechanisms involved in their formation. Dynamic light scattering experiments were performed to follow aggregation kinetics and aggregate characteristics in white wines at different temperatures (30-70 °C). Aggregation was followed during heating and cooling to 25 °C. Results were coupled with the study of the time-temperature dependence of heat-induced protein aggregation. At low temperature (40 °C), aggregation developed during heating. Colloidal equilibria were such that attractive interactions between species led to the rapid formation of micrometer-sized aggregates. At higher temperatures (60 and 70 °C), enhanced protein precipitation was expected and observed. However, high temperatures prevented aggregation, which mainly developed during cooling. Depending on the wine, cooling induced the formation of sub-micronic metastable aggregates stabilized by electrostatic repulsions, or the rapid formation of micrometer-sized aggregates, prone to sedimentation.


Subject(s)
Chemical Precipitation , Hot Temperature/adverse effects , Plant Proteins/chemistry , Wine/analysis , Nephelometry and Turbidimetry , Protein Stability , Quality Control
13.
Appl Environ Microbiol ; 75(13): 4231-9, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19411412

ABSTRACT

The gamma-aminobutyrate (GABA) shunt, an alternative route for the conversion of alpha-ketoglutarate to succinate, involves the glutamate decarboxylase Gad1p, the GABA transaminase Uga1p and the succinate semialdehyde dehydrogenase Uga2p. This pathway has been extensively described in plants and animals, but its function in yeast remains unclear. We show that the flux through Gad1p is insignificant during fermentation in rich sugar-containing medium, excluding a role for this pathway in redox homeostasis under anaerobic conditions or sugar stress. However, we found that up to 4 g of exogenous GABA/liter was efficiently consumed by yeast. We studied the fate of this consumed GABA. Most was converted into succinate, with a reaction yield of 0.7 mol/mol. We also showed that a large proportion of GABA was stored within cells, indicating a possible role for this molecule in stress tolerance mechanisms or nitrogen storage. Furthermore, based on enzymatic and metabolic evidence, we identified an alternative route for GABA catabolism, involving the reduction of succinate-semialdehyde into gamma-hydroxybutyric acid and the polymerization of gamma-hydroxybutyric acid to form poly-(3-hydroxybutyric acid-co-4-hydroxybutyric acid). This study provides the first demonstration of a native route for the formation of this polymer in yeast. Our findings shed new light on the GABA pathway and open up new opportunities for industrial applications.


Subject(s)
Hydroxybutyrates/metabolism , Polyesters/metabolism , Saccharomyces cerevisiae/metabolism , gamma-Aminobutyric Acid/metabolism , 4-Aminobutyrate Transaminase/metabolism , Fermentation , Glutamate Decarboxylase/metabolism , Ketoglutaric Acids/metabolism , Metabolic Networks and Pathways , Models, Biological , Saccharomyces cerevisiae Proteins/metabolism , Succinate-Semialdehyde Dehydrogenase (NADP+)/metabolism , Succinic Acid/metabolism
14.
Curr Genet ; 52(2): 55-63, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17594096

ABSTRACT

In the yeast, environmental challenges are known to induce both specific and general stress response. The HSP30 gene is strongly induced when cells are exposed to various stresses but this activation is largely independent of the major stress-related transcription factor Hsf1p and partly independent from Msn2p/Msn4p. In order to identify new potential regulators of HSP30 we isolated insertion mutants affected in HSP30 expression. We identified SFL1 gene encoding a protein previously shown to repress several genes. We show that Sfl1 is involved in the transcriptional activation of HSP30. Mutation of sfl1 reduces HSP30-lacZ expression under both basal and stress-induced conditions. We also show, using site-directed mutagenesis, that HSL motifs (Heat-Shock-Like putative DNA binding sequence) located in HSP30 promoter are required for HSP30 activation. Finally, a genome-wide analysis of the effects of SFL1 deletion on gene expression revealed that Sfl1p controls the expression of a small number of genes, with some being activated by the protein and others repressed. As a whole our data show that Sfl1p is a key component of the transcriptional control of the stress responsive gene HSP30. Moreover, we show that Sfl1, which was previously described as being a transcriptional repressor, can also act as an activator.


Subject(s)
Genes, Fungal , HSP30 Heat-Shock Proteins/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Transcription Factors/metabolism , Base Sequence , DNA Primers/genetics , DNA, Fungal/genetics , Ethanol/pharmacology , Gene Deletion , Gene Expression Regulation, Fungal , Genome, Fungal , Lac Operon , Molecular Sequence Data , Mutagenesis, Insertional , Mutagenesis, Site-Directed , Mutation , Oligonucleotide Array Sequence Analysis , Phenotype , Promoter Regions, Genetic , Saccharomyces cerevisiae/drug effects , Transcription Factors/genetics , Transcriptional Activation
15.
J Am Chem Soc ; 128(11): 3488-9, 2006 Mar 22.
Article in English | MEDLINE | ID: mdl-16536500

ABSTRACT

A new type of very compact Pacman bis-porphyrin scaffold has been obtained in which a calix[4]arene spacer provides both cofacial preorganization and flexibility. Changes in the distance between the two tetrapyrrolic macrocycles can be triggered by electrochemistry, where closed and open conformers can be interconverted in a handclapping motion.

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