Champagne Bubbles : Isolation and Characterization of amphiphilic macromolecules responsible for the stability of the collar at the Champagne / air interface

International audienceThe effervescence and the stability of the ring of fine bubbles crowning the surface of a champagne glass, the “collar”, constitute one of the hallmarks of Champagne. Defects in the stability of this collar are not well understood and account for a significant proportion of bottle return. This study aims to better understand the surface properties of champagne wine such that the foaming properties can be controlled more effectively. Early studies on Champagne foaming properties using the “Mosalux” measurement of the foam level formed by air flow in champagne through fritted glass pointed to a link between protein concentration and foam level [5] but no satisfactory correlation between protein content and foam stability was established. Later measurements were conducted with either ultra-filtrates or ultra-concentrates [4]. The authors demonstrated that macromolecule concentration was an essential parameter in the foam stability. The stability of bubbles is usually ascribed to the presence of an adsorption layer formed at the gas/liquid interface and its properties [3]. Thus surface properties of Champagne were analysed by ellipsometry and tensiometry. Measurements conducted on base wine, on ultra-filtered base wines and degassed champagne samples showed the presence of an adsorption layer formed at the air/champagne wine interface [6] and that adsorption layer being composed of macromolecules in a 104 to 105 molecular range [7]. Previous studies on champagne wine macromolecules had shown wine macromolecules to be mostly proteins and polysaccharides [8] with very little insight as to the chemical constitution. The present study describes the isolation and characterization of these macromolecules and their link with the adsorption layer

AS PROTEÍNAS DE FOLHA DE MANDIOCA: ASPECTOS FISIOLÓGICOS, NUTRICIONAIS E IMPORTÂNCIA TECNOLÓGICA

Some aspects of leaf proteins, specially from cassava (Manihot esculenta Crantz), as physiologic origin, amino acid composition, biochemical properties, nutritional role and technological process are reviewed. Cassava leaves present high protein content (20-30% w/w dry basis), of satisfactory quality when compared to FAO recommended pattern, and also high content of vitamins A and C and minerals. Some potential applications for human nutrition, animal feed or biotechnology industries are discussed. Alguns aspectos ligados à tecnologia de proteínas de folhas, com ênfase para as folhas de mandioca (Manihot esculenta Crantz), são revisados. A composição em aminoácidos, as propriedades bioquímicas, a importância nutricional e os princípios dos métodos de extração são apresentados. As folhas de mandioca apresentam elevado teor de proteínas (20-30% base seca), de valor nutricional adequado às recomendações da FAO, além de altos teores de vitaminas A e C e de minerais. Algumas aplicações potenciais em nutrição humana ou animal ou como substrato para a indústria de biotecnologia são discutidas

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Composes lipidiques accompagnant les proteines foliaires

National audienc

Effets de composés polyphénoliques sur la structure et les propriétés de couches d'adsorption de caséine B en milieu hydro-alcoolique

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Propriétés spectroscopiques des polyphénols. II - Propriétés spectroscopiques des flavonols et de leurs complexes avec le chlorure d'aluminium

National audienc

ETUDE DE COUCHES D'ADSORPTION DE MACROMOLECULES A L'INTERFACE CHAMPAGNE/AIR (APPLICATION DE LA METHODE DE LA GOUTTE PENDANTE A LA PREVISION DES PROPRIETES MOUSSANTES)

PARIS-BIUSJ-Physique recherche (751052113) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF