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

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

Vapour partition of aroma compounds in strawberry flavoured custard cream and effect of fat content

Gas–matrix partition coefficients (k) of volatile compounds of a strawberry flavour added to a complex model system (custard dessert, COST action 921 recipe) were determined. The influence of fat content on the volatility of the strawberry aroma compounds was investigated using full fat milk- (FFM) and skimmed milk- (SM) custards. For the purpose of this study, the phase ratio variation (PRV) method was used because of its easy application for a mixture of volatiles without requiring any calibration. From the 15 aroma compounds present in the flavouring mixture, seven were volatile enough to be detected and concentrated enough to allow the calculation of k values. Gas–matrix partition coefficients were compared to gas–water partition coefficients. For some aroma compounds (ethyl hexanoate, ethyl butanoate, and hexanal) a significantly lower k value was observed in FFM-custard than in water, indicating a retention effect caused by the matrix. As expected, the fat content and the hydrophobicity of the volatile compounds were of great importance to explain the differences between partition coefficients in SM custards and in FFM custards: for SM-custard, a higher release in the vapour phase was observed than for FFM-custard; the more hydrophobic the aroma compound, the higher the effect. Moreover, ethyl butanoate and hexanal were less retained in SM-custard than in water. This may be attributed to a salting-out effect due to sucrose. The results of this study indicate the importance of the interactions between volatiles and non-volatile compounds as well as of the chemical and physical properties of the aroma compounds in affecting the composition of the gas phase at equilibrium with a complex matrix. More than that, they provided a basis for the studies developed within COST action 921 with the flavoured custard model system

Freeze-thaw stability of konjac glucomannane-potato starch gels: Stability from macroscopic to microscopic scale, using image processing

Freeze-thaw (FT) stability is often used to assess the ability of a gel to support the damage induced byfreezing; selected parameters such as drip loss, damage to structure etc can be used to assess the freezetolerance of a gel. Konjac glucomannan (KGM) is a very specific hydrocolloid able to trap 100 timesits weight in water; it has not been studied so far as an improver to enhance FT stability. The aim of the study was to show that the presence of a small quantity of konjac glucomannan (KGM)in potato starch suspension increased the stability of carvacrol antioxidant trapping. FT cycles wereused to accelerate the ageing of the product and to assess its stability. In addition to drip lossesdetermination, the stability of carvacrol trapping was evaluated by the quantification of carvacrol inthe syneresis liquid. Microscopic and macroscopic scales were considered with microscopy. Themoment of the addition of carvacrol and the presence of KGM both had an effect on the stability ofcarvacrol trapping and of the structure of the gel. KGM promoted amylose retrogradation but sloweddown amylopectin retrogradation. The stability of potato starch gels can be improved by the addition of a small quantity of KGM, which showed a "cryoprotectant" behaviour. New method to characterizethe micro and macrostructure from SEM images processing has also been proposed. The processing ofmicroscopy images was done using Generalized Fourier Descriptors and allowed the characterization of each sample. The carvacrol addition lowered the physical stability of the gel with larger pores and increased syneresis. On the contrary, the KGM addition increased the size of the pores but preventedthe formation of very large pores and reduced syneresis. The most stable system was obtained by theaddition of carvacrol at the end of heating, in a konjac glucomannane potato starch gel. © 2018 International Institute of Refrigeration. All rights reserved

Expressing forest origins in the chemical composition of cooperage oak woods and corresponding wines by using FTICR-MS.

A non-targeted, ultra-high-resolution mass spectrometric, direct analysis of oak-wood extracts from two species (Quercus robur L. and Quercus petraea Liebl.) from three French forest, and of a wine aged in barrels derived there from has been performed to identify families of metabolites that could discriminate both the species and the geographical origin of woods. From 12 T ultra-high-resolution Fourier transform ion cyclotron resonance mass spectra of wood extracts, hundreds of mass signals were identified its possible significant biomarkers of the two species, with phenolic and carbohydrate moieties leading the differentiation between Q. robur and Q. petraea, respectively, as corroborated by both FTMS and NMR data. For the first time, it is shown that oak woods can also be discriminated oil the basis of hundreds of forest-related compounds, and particular emphasis is put on sessile oaks from the Troncais forest, for which sugars are significantly discriminant. Despite the higher complexity and diversity of wine metabolites, forest-related compounds can also be detected in wines aged in related barrels. It is only by using these non-targeted analyses that such innovative results, which reveal specific chemodiversities of natural materials, can be obtained

Authentication approach of the chemodiversity of grape and wine by FTICR-MS.

The metabolic composition of grapes and related wines results from a complex interplay between environmental, genetic and human factors which are not easily or possibly resolvable into their unambiguous individual contributions. Whether it is in the vineyard or in the cellar, several processes can indeed subtly modulate the characteristics of grape and wine, and these modulations often involve 'trace' amounts and interplay of metabolites within a complex matrix. As a consequence, considering wine as a complex biological system, the whole of which being more than the sum of its parts, is likely to provide deeper understanding of specificities associated with varieties and/or geographical origins and/or wine making practices. We show that non-targeted analyses of grape and wine products by ultrahigh resolution mass spectrometry can reveal snapshots of their chemodiversities, and that these chemodiversities, characterized by thousands of metabolites, precisely hold fingerprints of specific environmental parameters such as the "terroir" of a wine or even of oaks used for barrel ageing