Redox Potential: Monitoring and Role in Development of Aroma Compounds, Rheological Properties and Survival of Oxygen Sensitive Strains During the Manufacture of Fermented Dairy Products

International audienc

Interactions between bacterial surfaces and milk proteins, impact on food emulsions stability

Bacteria possess physicochemical surface properties such as hydrophobicity, Lewis acid/base and charge which are involved in physicochemical interactions between cells and interfaces. Moreover, food matrices are complex and heterogeneous media, with a microstructure depending on interactions between the components in media (van der Waals, electrostatic or structural forces, etc.). Despite the presence of bacteria in fermented products, few works have investigated how bacteria interact with other food components. The objective of the present study was to determine the effects of the surface properties of lactic acid bacteria on the stability of model food emulsions. The bacteria were added to oil/water emulsions stabilized by milk proteins (sodium caseinate, whey proteins concentrate or whey proteins isolate) at different pH (from 3 to 7.5). The effect of bacteria on the emulsions stability depended on the surface properties of strains and also on the characteristics of emulsions. Flocculation and aggregation phenomena were observed in emulsion at pHs for which the bacterial surface charge was opposed to the one of the proteins. The effects of bacteria on the stability of emulsion depended also on the concentration of cations present in media such as Ca2+. These results show that the bacteria through their surface properties could interact with other compounds in matrices, consequently affecting the stability of emulsions. The knowledge and choice of bacteria depending on their surface properties could be one of the important factors to control the stability of matrices such as fermentation media or fermented products.Région Bourgogne, Agence Universitaire de la Francophonie

Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

Spatial distribution of surface runoff and soil erosion on parcels under temperate climate

Abstract;Supplement IIInternational audienc

Analyse spatialisee du ruissellement a l'echelle de la parcelle

National audienc

Spatial variations of sheet flow and sediment transport on agricultural field

International audienc

Etats de surface du sol et risques de ruissellement et d'érosion

Dans le contexte armoricain, le ruissellement de surface est étudié, bien qu'il ne représente qu'une fraction mineure de l'écoulement : c'est en effet le vecteur privilégié des polluants liés aux particules de sol. Le ruissellement est lié à l'intensification agricole dans une région où les sols sont de faible stabilité structurale, et sont donc sensibles à la battance et à la prise en masse. Une analyse de la distribution spatiale du ruissellement, le long du versant et au cours d'une année, réalisée grâce à un ensemble de collecteurs répartis sur le versant, est présentée. Cette analyse est reliée à un ensemble de mesures physiques d'infiltrométrie réalisées par TRIMS. Ces mesures sont réalisées à différents niveaux de pente, à différentes périodes, sur et sans passage de roue. Elles montrent que la conductivité hydraulique varie notablement sur le versant et au cours d'une année culturale. Cette technique de mesure, qui concerne tout le domaine proche de la saturation, permet de connaître la gamme porosité concernée par ces variations spatiales et temporelles et de discuter des processus mis en jeu. (Résumé d'auteur