Multi-response Modelling of the Maillard reaction in a model cheese

International audienceProcessed cheese derives from a secondary milk processing step that involves mixing and heating dairy (cheese, butter and milk powders) and non-dairy products (emulsifiers). This processing yields a homogeneous product, usually spreadable, with a shelf-life often longer than 6 months. During cheese processing and storage, lipid oxidation, caramelization and Maillard reactions occur and produce odour-active compounds. In this study, a methodological approach was used in order to (i) identify odorants responsible for flavor attributes or compouds involved in the reaction chain, (ii) monitor the evolution of these markers during the heat treatment applied to the matrix, (iii) establish an observable reaction scheme and (iv) model and predict the evolution of these compounds during thermal operations. In this aim, a model cheese and a cooking cell were elaborated. Various couplings of gas chromatography with olfactometry were used to identify odorous compounds. Two-dimensional comprehensive chromatography allowed a semi-quantitation of trace and ultra-trace compounds, while precursors were quantitated by high performance liquid chromatography. An observable reaction scheme of the Maillard reaction was extracted from these data and makes the multi-response modeling step possible despite a partial quantitation of the volatile compounds. Finally, we obtained a formal model combining 19 components (including four odorants) connected by 14 stoechiometric balanced reactions. This model makes it possible to predict the evolution of these components depending on the initial content of lactose, galactose and according to the heat treatment applied to the cheese matrix. This work was carried out with the financial support of the ANR-Agence Nationale de la Recherche-The French National Research Agency under the Programme National de Recherche en Alimentation et nutrition humaine , project ANR-06-PNRA-023REACTIAL "Prediction and control of the appearance or disappearance of reactional markers during food process and conservation "

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Contribution au développement de l'analyse non séparative d'espaces de tête spectrométrie de masse

CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Identification des composés aromatiques clés impliqués dans les comportements d'attrait ou de rejet d'un produit laitier par les consommateurs

L'objectif de ce travail était les composés odorantes clés de l'arôme du camenbert et de rechercher ceux qui dont susceptibles d'induire des compotements d'attrait ou de rejet chez les consommateurs. Un nouvel outil de CPG-O à huit voies synchrones a permis de repérer et d'identifier plus de 27 composés volatils odorants majeurs dans 9 fromages représentatifs de la diversité aromatique du camenbert. Un sous-ensemble de ces composés a été sélectionné pour appréhender les préférences qu'ils sont susceptibles d'induire chez des consommateurs de camenbert. Pour cela, nous avons réalisé deux études sur deux panels d'environ 180 consommateurs répartis selon trois "segments de préférence", selon qu'ils appréciaient les camenberts "peu affinés", "typés", ou "corsés". Ces études ont permis d'acquérir des informations sur les préférences induites "hors contexte produits" et en "contexte produit" et de mettre en evidence 8 composés "préférences actifs"CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

CONTRIBUTION A L'AMELIORATION DE L'ANALYSE DE LA FRACTION VOLATILE DE PRODUITS RICHES EN EAU PAR ESPACE DE TETE DYNAMIQUE COUPLE A LA CHROMATOGRAPHIE EN PHASE GAZEUSE ET SPECTROMETRIE DE MASSE

L'OBJECTIF DE CE TRAVAIL ETAIT DE METTRE EN UVRE DES PROCEDES ANALYTIQUES PERMETTANT DE LIMITER LES ARTEFACTS DUS A L'EAU LORS DE L'ANALYSE DE LA FRACTION VOLATILE DE PRODUITS RICHES EN EAU PAR ESPACE DE TETE DYNAMIQUE - CHROMATOGRAPHIE EN PHASE GAZEUSE ET SPECTROMETRIE DE MASSE. TOUT D'ABORD, DES PROCEDURES REPUTEES APTES A REDUIRE CES ARTEFACTS ONT ETE TESTEES AFIN DE DECRIRE LEURS EFFETS SUR LES ANALYSES D'UN FROMAGE. CES PROCEDURES CONSISTAIENT A ELIMINER L'EAU AU NIVEAU DU PIEGE PAR UNE ETAPE DE DRY-PURGE, A CONDENSER L'EAU PAR UN PIEGE FROID OU A DIMINUER L'ACTIVITE DE L'EAU DE L'ECHANTILLON PAR AJOUT DE SELS HYGROSCOPIQUES. ENSUITE DES ARTEFACTS ANALYTIQUES ONT ETE INDUITS PAR INTRODUCTION DE VAPEUR D'EAU DANS L'ESPACE DE TETE DE PRODUITS SECS AFIN DE LOCALISER LEUR ORIGINE DANS LA CHAINE ANALYTIQUE. ENFIN, LA PREPARATION DE L'ECHANTILLON PAR ULTRA-CENTRIFUGATION A ETE TESTEE AFIN D'EXTRAIRE SA PHASE LIPIDIQUE. LES SOLUTIONS TESTEES ONT PERMIS D'AMELIORER LA QUALITE DU SIGNAL CHROMATOGRAPHIQUE (DIMINUTION DU BRUIT ANALYTIQUE, AMELIORATION DE LA FORME DES PICS, ABSENCE DE TRAINEES) EN LIMITANT L'INTRODUCTION D'EAU DANS LE CIRCUIT ANALYTIQUE, MAIS AVAIENT POUR INCONVENIENT DE MODIFIER LES PROFILS CHROMATOGRAPHIQUES DU PRODUIT ETUDIE (CHANGEMENT DES PROPORTIONS ENTRE LES COMPOSES, DISPARITIONS OU APPARITIONS DE CERTAINS PICS). LES ARTEFACTS ANALYTIQUES MIS EN EVIDENCE ETAIENT PRINCIPALEMENT DUS A DES MECANISMES DE COMPETITION ENTRE L'EAU ET LES MOLECULES VOLATILES AU NIVEAU DE L'ADSORBANT. LA PHASE LIPIDIQUE OBTENUE PAR ULTRACENTRIFUGATION A ETE CHAUFFEE A 80\C LORS DE L'ANALYSE AFIN D'AMELIORER L'EXTRACTION DES COMPOSES VOLATILS. CETTE METHODE A ETE APPLIQUEE AU DOSAGE DES MOLECULES TERPENIQUES DANS UN FROMAGE.CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Multi-response Modelling of the Maillard reaction in a model cheese

International audienceProcessed cheese derives from a secondary milk processing step that involves mixing and heating dairy (cheese, butter and milk powders) and non-dairy products (emulsifiers). This processing yields a homogeneous product, usually spreadable, with a shelf-life often longer than 6 months. During cheese processing and storage, lipid oxidation, caramelization and Maillard reactions occur and produce odour-active compounds. In this study, a methodological approach was used in order to (i) identify odorants responsible for flavor attributes or compouds involved in the reaction chain, (ii) monitor the evolution of these markers during the heat treatment applied to the matrix, (iii) establish an observable reaction scheme and (iv) model and predict the evolution of these compounds during thermal operations. In this aim, a model cheese and a cooking cell were elaborated. Various couplings of gas chromatography with olfactometry were used to identify odorous compounds. Two-dimensional comprehensive chromatography allowed a semi-quantitation of trace and ultra-trace compounds, while precursors were quantitated by high performance liquid chromatography. An observable reaction scheme of the Maillard reaction was extracted from these data and makes the multi-response modeling step possible despite a partial quantitation of the volatile compounds. Finally, we obtained a formal model combining 19 components (including four odorants) connected by 14 stoechiometric balanced reactions. This model makes it possible to predict the evolution of these components depending on the initial content of lactose, galactose and according to the heat treatment applied to the cheese matrix. This work was carried out with the financial support of the ANR-Agence Nationale de la Recherche-The French National Research Agency under the Programme National de Recherche en Alimentation et nutrition humaine , project ANR-06-PNRA-023REACTIAL "Prediction and control of the appearance or disappearance of reactional markers during food process and conservation "

Cardiac myosin activation with omecamtiv mecarbil in systolic heart failure

BACKGROUND The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown. METHODS We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes. RESULTS During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups. CONCLUSIONS Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016 -002299-28.)