Search results for "wine"

Principal Parameters of Grape Ripening and Wine Fermentation

2008

Dynamics of Microbial Populations during Fermentation of Wines from the Utiel-Requena Region of Spain

1989

The dynamics of fungi, yeasts, and lactic acid bacteria during fermentation of four musts were studied. Fungi disappeared quickly in the fermenting must. The lactic acid bacteria population diminished during alcoholic fermentation, then they increased and performed malolactic fermentation. Yeasts grew quickly, reaching maximum populations at different times depending on the vinification treatment.

Interactions micro-organismes - bois et impact sur les propriétés physico-chimiques du vin : fermentation malolactique par le biofilm de Oenococcus o…

2015

Malolactic fermentation improves wine quality, mainly by decreasing acidity. It is carried out by lactic acid bacteria, mainly Oenococcus oeni. This species is favored for its efficiency and its organoleptic outcome. O. oeni ability to withstand wine stress and to keep its fermentation activity is a subject of major interest.Samples of oak showed that O. oeni adheres to wood and is able to persist for several months in wine. However, in the majority of natural habitats, microorganisms grow attached to a surface, within a structured ecosystem called biofilm. In this form of life, cells benefit from an increased stress resistance.These two properties, adherence to a surface and stress resista…

A chromatochemometric approach for evaluating and selecting the perfume maceration time.

2010

Abstract A chemometric treatment of the data obtained by gas chromatography (GC) with flame ionization detector (FID) has been proposed to study the maceration time involved in perfumes manufacture with the final purpose of reducing this time but preserving the organoleptic characteristics of the perfume that is being elaborated. In this sense, GC–FID chromatograms were used as a fingerprint of perfume samples subjected to different maceration times, and data were treated by linear discriminant analysis (LDA), by comparing to a set of samples known to be macerated or not, which were used as calibration objects. The GC–FID methodology combined with the treatment of data by LDA has been appli…

Simultaneous enzymatic determination of l(−) malic acid and l(+) lactic acid in wine by flow injection analysis

1991

Abstract A simultaneous determination of two organic acid species in wine by a flow injection analysis method using enzyme-immobilized open tubular reactors is described. The design of the optimal geometry of the FIA system is especially important to avoid the matrix fluorescence. Reproducible results were obtained in the determination of l (−) malic acid and l (+) lactic acid using l -MDH and l -LDH, respectively. The assay reactions utilize the fluorimetric determination of a common product, NADH. The sample was dialyzed on line and injected into the FIA-system. The system responds linearly (log-log calibration graphs) to the injected sample (80 μl) in concentrations ranging from 0·1 m m …

Synthesis and preliminary evaluation of (R,R)(S,S) 5-(2-(2-[4-(2-[18F]fluoroethoxy)phenyl]-1-methylethylamino)-1-hydroxyethyl)-benzene-1,3-diol ([18F…

2003

The 18 F-labeled b2-adrenergic receptor ligand (R,R)(S,S) 5-(2-(2-(4-(2-( 18 F)fluoroethoxy)phenyl)-1-methylethylamino)-1- hydroxyethyl)-benzene-1,3-diol, a derivative of the original highly selective racemic fenoterol, was synthesized in an overall radio- chemical yield of 20% after 65 min with a radiochemical purity higher than 98%. The specific activity was in the range of 50-60 GBq/mmol. In vitro testing of the non-radioactive fluorinated fenoterol derivative with isolated guinea pig trachea was conducted to obtain an IC50 value of 60 nM. Preliminary ex vivo organ distribution and in vivo experiments with positron emission tomography (PET) on guinea pigs were performed to study the biod…

Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation

2010

BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…

Aroma compound sorption by oak wood in a model wine

2001

Oak wood used for wine barrels was immersed into a model wine containing eight aroma compounds (e.g., aromatic and terpene alcohols, ethyl esters, and aldehyde), for which activity coefficients in water and model wine were determined using the mutual solubility measurement. A mass balance of these volatiles considering their reactivity in model wine was established. For most of the studied aroma compounds, and mainly for linalool and ethyl octanoate, a sorption behavior into wood was reported for the first time. This phenomenon was selective and could not be related to the solubilities in model wine and hydrophobicities of the studied aroma compounds, suggesting that acid-base and polar cha…

Enological characterization of natural hybrids from Saccharomyces cerevisiae and S. kudriavzevii.

2007

The effect of yeasts on wine flavor response is of primary importance. The genus Saccharomyces, and mainly the species Saccharomyces cerevisiae, is responsible for alcoholic fermentation. Recently, several novel yeast isolates from wines have been described as hybrid yeasts between S. cerevisiae x S. kudriavzevii. We have analyzed their influence on two grape musts (Macabeo and Tempranillo) in fermentations conducted at four different temperatures (14, 18, 22 and 32 degrees C) by studying volatile compound production, sugar assimilation and other characteristics influencing the enological properties of wine caused by the impact of yeast. Hybrid yeasts behave particularly well at 14, 18 and …

Pulsed electric field applications for the extraction of compounds and fractions (fruit juices, winery, oils, by-products, etc.)

2020

Abstract The pulsed electric field (PEF) is well known to have a significant effect on the rate of various processes in the food industry. Food processes can be completed rapidly with higher efficiency, high reproducibility, reducing the processing cost, simplifying manipulation, and work-up, giving higher purity of the final product, eliminating posttreatment of wastewater and less energy when compared to a conventional process using the PEF. The advantages of using the PEF for food processing is to get high quality fresh-like liquid foods with excellent flavor, nutritional value, and shelf life retaining the fresh aroma, taste, and appearance. This chapter presents a complete picture of c…