Changes in terpene content in milk from pasture-fed cows

International audience

Influence of the addition of pasture plant essential oil in milk on the chemical and sensory properties of Cantal type cheeses

National audience

Effects of mountain grassland maturity stage and grazing management on carotenoids in sward and cow's milk

Carotenoids are involved in the sensorial and nutritional values of dairy products. In grazing systems, both herbage maturity stage and grazing management may affect the amount of carotenoid ingested, thus these factors may affect carotenoid concentrations in milk. Two homogenous plots of mountain grassland (1.4 and 2.0 ha) were grazed during two cycles of growth by 6 dairy cows in mid lactation, in strip (SG) and rotational grazing (RG), respectively. We monitored the changes in carotenoid concentrations in sward and milk, measured by HPLC twice a week. Seven carotenoids were identified in the sward: violaxanthin, antheraxanthin, epilutein, lutein, zeaxanthin, ß-carotene and 13-cis ß-carot…

Thermomechanical Behavior of Beams Covered with Viscoelastic Patches

International audience; Infrared thermography is a non-destructive test method based on infrared measurement that provides a luminance map of the thermal scene observed, converting to temperature. The thermographic study allows a surface observation of the thermal effects in order to display the result as a film of the temperature distribution [1]. The present study focuses on the detection of volumetric energy sources in beams covered by viscoelastic patches.

Étude Du Comportement Thermomécanique De Structures Recouvertes De Patchs Visco-Contraints

International audience; La thermographie infrarouge est une méthode qui permet d'obtenir la carte de luminance de la scène thermique observée, de la convertir en température apparente et d'afficher ou d'enregistrer le résultat sous la forme d'une image de la distribution de la température. Nous l'utilisons ici, pour la détection à distance, des sources d'énergie dans des structures formées de poutres recouvertes de patchs viscoélastiques.

Characterization of the Dynamic Interaction between Chassis and Powertrain of a Vehicle Using the Coupling Matrix

International audience; This study is concerned with the vibration transmission between two subsystems of a vehicle: the chassis which is considered as an elastic structure and the powertrain which is considered as a rigid body. The study is carried out based on a new coupling matrix constructed from equations of dynamic behavior of each subsystems. This matrix depends only on the impedance matrices of the two subsystems and the mechanical characteristics of the linking mounts. Under some assumptions, a simplified expression to obtain the overall behaviour of the entire system is proposed. Despite its sensitivity to the degree of coupling between the subsystems, this method can be applied t…

More clues of the occurrence and flavor impact of solerone in wine

International audience

Near-site simultaneous impacts response of carbon/epoxy composite laminates

More clues about Sensory Impact of Sotolon in Some Flor Sherry Wines

The olfactory impact of sotolon [4,5-dimethyl-3-hydroxy-2(5H)-furanone] in wines was first demonstrated in botrytized wines. In sherry wines it was recently found to occur at concentrations varying from 0 to 500 ppb. The olfactory detection threshold of a sample of purified racemic sotolon was determined to be lower (15 ppb) in white wine than its concentration in most sherries. Its flavor impact in sherries was calculated to be between 1 and 25 OUV. Using MCA of the data obtained from 22 wines (white wines, rancios, Spanish and French sherries) during two tasting sessions by wine professionals, significant positive correlations were found-between the concentration of sotolon and the typica…

The maturity stage of the grass affects milk fatty acids of cows grazing a mountain grassland

International audience; We aimed to quantify the effect of the growth stage of a mountain grassland pasture on the fatty acid (FA) composition of grass and milk. In June (growth) and October (regrowth), a mountain pasture was continuously grazed by six dairy cows in a strip grazing system. During June, the grass C18:3n-3 content decreased while C16:0, c9-C18:1 and C18:2n-6 content increased. During October, the grass FA composition was similar to that observed in the first part of June. During June, milk saturated FA (SFA) content increased while the sum of the trans FA and polyunsaturated FA (PUFA) content decreased, mainly due to the decrease in C18:3n-3 and c9t11-CLA percentages. At the …

Étude du comportement aux multi-impacts des structures composites

Dynamic Coupling Study between Substructures. Application to the Chassis-Powertrain Interaction

International audience

Multi-impact damage of laminated composite materials studied with a compressed air cannon

Changes in Terpene Content in Milk from Pasture-Fed Cows

Changes of terpene content in milk from cows grazing natural diversified upland pasture were examined in this observational trial. A homogeneous plot divided into 2 subplots was used from May 31 to July 1, 2003 (first growth) and again from October 1 to October 7, 2003 (vegetative regrowth). Each subplot was grazed by 6 dairy cows in 2 ways: strip grazing (SG), with new allocations of pasture strips at 2-d intervals, and paddock grazing (PG). The PG subplot was divided into 3 paddocks and the cows were moved to a new paddock on June 13 and June 24, 2003. Milk from the 6 cows was collected twice a week, pooled, and used for terpene analyses by dynamic headspace gas chromatography-mass spectr…

Addition of pasture plant essential oil in milk: Influence on chemical and sensory properties of milk and cheese

The aim of this experiment was to study the effect of the addition, to milk, of an essential oil (EO) obtained from the hydrodistillation of plants collected from a mountain natural pasture on the milk and cheese sensory properties. The EO was mainly composed of terpenoid compounds (67 of the 95 compounds identified) as well as ketones, aldehydes, alcohols, esters, alkanes, and benzenic compounds. In milk, the addition of this EO at the concentration of 0.1 microL/L did not influence its sensory properties, whereas at 1.0 microL/L, sensory properties were modified. In cheeses, the effect of adding EO into milk was studied in an experimental dairy plant allowing the production of small Canta…

Optimization of Passive Constrained Layer Damping (Pcld) Treatments for Vibration Reduction

An efficient method to reduce the frequency averaged transverse vibration level of aplate by optimizing the position of attached passive constrained layer damping PCLD is presented.This method uses a multilayer anisotropic plate model which is an equivalent single layer platemodel (ESL) where transverse shear stresses and displacements are continuous at each layer’sinterfaces. Hence, for a laminate composed of an arbitrary number of layers, all the quantities arerelated to those of the first layer. The optimization process is based on the use of the ESL platemodel combined with the genetic algorithm (GA) and Latin Hypercube Sampling (LHS) algorithmimplemented in a Rayleigh-Ritz resolution p…

Influence of the botanical diversity and development stage of mountain pastures on milk fatty acid composition, carotenoids, fat-soluble vitamins and sensory properties

International audience