Search results for "chromatography"

2019

The treatment of enteric bacterial infections using oral bacteriophage therapy can be challenging since the harsh acidic stomach environment renders phages inactive during transit through the gastrointestinal tract. Solid oral dosage forms allowing site-specific gastrointestinal delivery of high doses of phages, e.g., using a pH or enzymatic trigger, would be a game changer for the nascent industry trying to demonstrate the efficacy of phages, including engineered phages for gut microbiome modulation in expensive clinical trials. Spray-drying is a scalable, low-cost process for producing pharmaceutical agents in dry powder form. Encapsulation of a model Salmonella-specific phage (Myoviridae…

Identification of tasty compounds of cooked cured ham : physico-chemical and sensory approaches

1997

Abstract Tasty compounds from meat have not been studied in depth. The aim of this work was to isolate, identify and quantify tasty compounds from cooked cured ham and to link them to the sensory evaluations of the fractions from which they are extracted. The extraction of the water-soluble fraction from ham was done by an hydraulic press. The crude extract was ultrafiltered and both gel filtration and nanofiltration allowed to obtain edible fractions. Some links between the physicochemical and sensory data have been found, in particular, the umami taste was related to the presence of IMP and monosodium glutamate. The direct influence of proteolytic peptides on this taste is discussed. More…

Innovative Green Technologies of Intensification for Valorization of Seafood and Their By-Products

2019

The activities linked to the fishing sector generate substantial quantities of by-products, which are often discarded or used as low-value ingredients in animal feed. However, these marine by-products are a prominent potential good source of bioactive compounds, with important functional properties that can be isolated or up-concentrated, giving them an added value in higher end markets, as for instance nutraceuticals and cosmetics. This valorization of fish by-products has been boosted by the increasing awareness of consumers regarding the relationship between diet and health, demanding new fish products with enhanced nutritional and functional properties. To obtain fish by-product-derived…

Role of aroma–matrix interactions on perception of structured emulsions

2011

The impact of the composition of spreads on in vivo aroma release and aroma perception was investigated using online proton transfer reaction mass spectrometry (PTR-MS) and sensory methodologies. Consumption of model products spread on bread induced a significant increase in aroma release and better discrimination in aroma perception, compared to when the product was tasted pure from a spoon. Dynamic release of a series of 10 aroma compounds was slower with the increase in solid fat content, and the quantity decreased when proteins were added. Sensory ranking of model products mostly confirmed the release results.

Characterisation of odour active compounds along extraction process from pea flour to pea protein extract

2013

International audience; Pisum sativum, rich in proteins, represents a main interest for human food. Nevertheless, pea products are underused because of their organoleptic characteristics. The extraction process of the proteins can partly explain the development of the typical flavour.The objective of the present study was to identify odour active compounds and to follow their evolution during four steps of the process (from pea flour to pea protein).Firstly, volatile compounds were extracted by Solvent Assisted Flavour Evaporation from each step and analysed by Gas Chromatography coupled with Mass Spectrometry and Olfactometry. Secondly, the volatile compounds, identified as odour active in…

Effect of iron chelates on oil–water interface, stabilized by milk proteins: The role of phosphate groups and pH. Prediction of iron transfer from aq…

2010

International audience; Iron incorporated into food systems induces oxidation and precipitation. The consequences are reduced bioavailability and a functional modification of other food components such as proteins. The iron-chelates such as ferrous bisglycinate represent a possibility to avoid side effects, since the iron is protected. The aim of this study is to investigate the effects of iron-chelates compounds on the properties of an oil/water interface stabilized by caseinate or β-lacotoglobulin, under environmental conditions at 20 °C. Analyses were performed using dynamic drop tensiometry during 5000 s. The aqueous bulk phase is an imidazole/acetate buffer (0.1 M), containing 0.4 × 10…

Geometry of conjugated double bonds of CLA isomers in a commercial mixture and in their hepatic 20∶4 metabolites

1999

Rats were fed a fat-free diet for 2 wk. After this period, while maintaining the animals on the same diet, the rats were given intragastrically 180 mg per day of a mixture of conjugated linoleic acids (CLA) as triacylglycerols. Gas chromatography mass spectrometry (GC-MS) analyses of this mixture, as well as hydrazine reduction and GC-MS and GC-Fourier transform infrared analyses of the resulting monoenes, revealed the presence of two major isomers, the 9c,11t- and the 10t,12c-18:2 accompanied by smaller amounts of the 8t, 10c and the 11c, 13t-18:2 isomers. Minor quantities of cis,cis and trans,trans conjugated isomers also were detected. The total fatty acid methyl esters from the liver li…

A detailed identification study on high-temperature degradation products of oleic and linoleic acid methyl esters by GC–MS and GC–FTIR

2012

GC-MS and GC-FTIR were complementarily applied to identify oxidation compounds formed under frying conditions in methyl oleate and linoleate heated at 180ºC. The study was focused on the compounds that originated through hydroperoxide scission that remain attached to the glyceridic backbone in fats and oils and form part of non-volatile molecules. Twenty one short-chain esterified compounds, consisting of 8 aldehydes, 3 methyl ketones, 4 primary alcohols, 5 alkanes and 1 furan, were identified. In addition, twenty non-esterified volatile compounds, consisting of alcohols, aldehydes and acids, were also identified as major non-esterified components. Furanoid compounds of 18 carbon atoms form…

The influence of storage conditions on flavour changes in human milk

2009

http://www.sciencedirect.com/ ; http://www.elsevier.com/; International audience; The effects of freeze-storage on human milk have been investigated with regard to sensory changes and modifications in the molecular composition of constituent odour-active volatiles. Sensory evaluation showed that fishy-metallic odour attributes are generated during storage, as are rancid-sweaty odour notes, which were described by panellists to be highly unpleasant. To monitor the dynamics of off-odour development in human milk, sensory evaluation in both orthonasal and retronasal mode was performed at defined time intervals of storage, with parallel evaluation of human milk samples that had been heated prio…

Partition of Indicaxanthin in Membrane Biomimetic Systems. A Kinetic and Modeling Approach

2009

The solubilization site of indicaxanthin (Ind) in lipid bilayers was investigated by the kinetics of Ind oxidation by peroxyl radicals in water and in aqueous/L-alpha-dipalmitoyl-phosphatidylcholine (DPPC) vesicles, pH 7.4, and 37.0 and 48.0 degrees C, that is, in a gel-like and a crystal liquidlike bilayer state, respectively. The time-dependent Ind absorbance decay, matched with a successful simulation of the reaction kinetic mechanism by Gepasi software, supported a multistep pathway. Computer-assisted analysis allowed calculation of the rate constants associated with the reactions involved, the values of which decreased with increasing DPPC concentration. The binding constant calculated…