Search results for "Lipids"
showing 10 items of 2228 documents
Characterisation and Anaerobic Batch Degradation of Materials Accumulating in Anaerobic Digesters Treating Poultry Slaughterhouse Waste
2001
We characterised materials accumulating in two failed mesophilic semi-continuous anaerobic digesters treating poultry slaughterhouse waste and, for reference, materials in the two well-performing digesters, to find the anaerobic degradability of these materials and the factors affecting their degradation. We also studied materials accumulating and stratifying in various layers in one of the two well-performing digesters. The material from the most severely failed digesters produced methane sluggishly and did not improve appreciably even with 33 percent dilution suggesting that the recovery of failed process is slow. The methane production was apparently affected by the accumulated long-chai…
Transfer of aroma compounds in water-lipid systems: binding tendency of beta-lactoglobulin.
1998
Interactions of volatile aroma compounds with protein in aqueous solutions, especially whey proteins, have received significant attention in recent years. This work attempts to improve our understanding of the mass transfer in multiphasic systems, such as emulsions at the lipid−water interface, and to reveal the role of β-lactoglobulin in the release rate of solutes. For this purpose the rotating diffusion cell has been used. From a practical point of view it enables evaluation of the transfer through the aqueous phase, through the oil and the interfacial transfer. The effect of β-lactoglobulin, medium pH, and solute concentration has been investigated. Benzaldehyde and 2-nonanone have been…
Probing Protein−Membrane Interactions Using Solid Supported Membranes
2011
International audience; Tethered bilayer lipid membranes have been used as a model system to mimic the interactions between the whey protein β-lactoglobulin and a lipid interface. The approach allowed for a detailed study of the lipid-protein interactions, the results being of possible importance in food and cosmetic applications. For such applications, lipid-protein interactions and the interfacial behavior are vital factors in controlling and manipulating process conditions such as emulsion stabilization and gelification. Lipid composition as well as the structural properties of the protein governed their interactions, which were probed by a combination of surface plasmon spectroscopy, ne…
Aroma production and fermentation performance of S. cerevisiae × S. kudriavzevii natural hybrids under cold oenological conditions
2019
This work aims to describe the wine fermentation characteristics of 23 natural S. cerevisiae × S. kudriavzevii hybrid yeasts related to fermentative environments isolated from different regions and their significance for the aroma spectra of the produced wines. Fermentations were performed at 12 °C in artificial must, and S. cerevisiae and S. kudriavzevii pure species strains were used for comparison purposes. We determined the relevant kinetic parameters of fermentation, the concentration of the main metabolites and the main aroma-related compounds produced after fermentation. The results revealed that some strains that show well-rounded characteristics could be profitable yeast starters f…
Amino acids and volatile compounds in wines from Cabernet Sauvignon and Tempranillo varieties subjected to malolactic fermentation in barrels
2012
The aim of the present paper is to compare the behaviour of industrial lactic bacteria and indigenous bacteria of the cellar when malolactic fermentation was carried out in barrels. The effects of these bacteria on the concentration of metabolised amino acids during malolactic fermentation and on the composition of volatile compounds both before and after malolactic fermentation are studied. The experiment was performed with wines of the Tempranillo and Cabernet Sauvignon varieties. An analysis has been made of the easily extractable volatile compounds of the wood and the compounds from the grapes, and the action of the yeasts during the alcoholic fermentation. Acetoin and diacetyl decreas…
Hydrolysis and sorption by Saccharomyces cerevisiae strains of Chardonnay grape must glycosides during fermentation
2005
Abstract Different Saccharomyces cerevisiae strains were tested for their ability to hydrolyse glycosyl–glucose (G–G) compounds present in Chardonnay must during alcoholic fermentation. The determination of glycosyl–glucose during the course of the alcoholic fermentation of Chardonnay grape must revealed that S. cerevisiae is able to hydrolyse G–G during alcoholic fermentation in wine conditions. The extent of hydrolysis vary from 17 to 57% of the initial glycoside concentration. In order to confirm that decrease in G–G concentration during alcoholic fermentation is due to hydrolytic action and not to sorption phenomenon, in the first experiment, an analysis of the osidic part of Chardonnay…
Toxicity of fatty acid hydroperoxides towards Yarrowia lipolytica: Implication of their membrane fluidizing action
2007
Abstract Linoleic acid hydroperoxide (HPOD), substrate of hydroperoxide lyase, an enzyme of the lipoxygenase pathway, can be transformed into many aromatic compounds, the so-called “green notes”. The presence of linoleic acid hydroperoxide in the culture medium of Yarrowia lipolytica, the yeast expressing the cloned hydroperoxide lyase of green bell pepper, undoubtedly exerted an inhibition on the growth and a toxic effect with 90% of yeast cells died after 120 min of exposition in 100 mM HPOD solution. The increase in cell membrane fluidity evaluated by measuring fluorescence generalized polarization with the increasing concentration of HPOD in the medium confirmed the fluidizing action of…
Circulating markers of retinal and optic nerve lipids
2013
Purpose Blood lipids are frequently used as a surrogate of lipid composition of peripheral tissues. Even if it is well accepted, such a relationship has never been clearly demonstrated for the eye. The aim of this study was to determine in human samples whether a lipidomic approach based on red blood cells could reveal associations between circulating and ocular lipid profiles. Methods Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on these tissues were done by both, gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS/MS). Results Gas chromatographic approach did not show…
Fatty-acid preference changes during development in Drosophila melanogaster.
2011
WOS:000296521400044; International audience; Fatty-acids (FAs) are required in the diet of many animals throughout their life. However, the mechanisms involved in the perception of and preferences for dietary saturated and unsaturated FAs (SFAs and UFAs, respectively) remain poorly explored, especially in insects. Using the model species Drosophila melanogaster, we measured the responses of wild-type larvae and adults to pure SFAs (14, 16, and 18 carbons) and UFAs (C18 with 1, 2, or 3 double-bonds). Individual and group behavioral tests revealed different preferences in larvae and adults. Larvae preferred UFAs whereas SFAs tended to induce both a strong aversion and a persistent aggregation…
Structures of single, double and triple layers of lipids adsorbed on graphene: Insights from all-atom molecular dynamics simulations
2017
Abstract Non-covalent functionalization of graphene with phospholipids is a promising technique for biosensing applications and intracellular delivery of analytical probes and drugs. However, molecular details of the self-assembly of lipids on graphene surface is still poorly understood and hard to control. There is a clear lack of understanding of why various kinds of lipid aggregates can form on graphene. In the current work, we address this question by investigating equilibrium and dynamical properties of lipid layers adsorbed on graphene in water environment and in vacuum using all-atom Molecular Dynamics simulations. It is shown that a variety of lipid aggregates can form on top of gra…