Search results for "Flavour"
showing 10 items of 310 documents
The caramel flavour: impacts of the volatile and the non-volatile fraction on perception
2013
The aim of this thesis was to investigate the impact of the volatile odorant fraction and the non-volatile fraction on the perception of caramel flavour. The first step focused on the analytical characterization of the volatile odorant fraction of caramel using Gas Chromatography coupled to Olfactometry (GC/O), GC/Mass Spectrometry (GC/MS) and heart-cutting MDGC/MS/O. Results highlighted the presence of more than one hundred compounds and demonstrated the complexity of the caramel volatile fraction. The objective of the second step was to understand the contribution of odorant compounds identified to the caramel aroma typicality. Literature shows that odour intensity is not sufficient to ev…
Relationship between sensory profiles and odor-active compounds detected by Gas-Chromatography olfactometry
2011
Cheese flavour has been widely studied and key-aroma compounds identified. However the strategies involved were mostly correlation studies between quantitative measurements of aroma compounds and either gas chromatography olfactometry (GC-O) data or sensory data. These correlations do not take in account the differences in the Stevens’ slopes relating sensory perception and concentration and perception thresholds. The objective of this study was thus to explain sensory perception of cheese by the intensity of single molecules measured by GC-O analysis. Seven commercial semi-hard cheeses were evaluated by a sensory descriptive analysis. Thirteen odour attributes were evaluated by a panel of …
Ruminant fat volatiles as affected by diet. A review.
2006
Volatile compounds in meat have been widely studied for their favourable or undesirable effects on meat flavour, or for their potential use in tracing the animal feeding system. To date, the chemical mechanisms causing the appearance of volatile compounds in meat have been largely understood. Several variables are involved in the accumulation of volatiles in animal tissues and among them animal diet plays a key role. The purpose of the present review is to highlight the effects of different dietary regimes (concentrate, green grass and fat-enriched diets) on the appearance of fat volatile compounds in ruminant meat. Grain-based diets induce greater accumulations in meat of branched-chain fa…
Effect of Drying Condition on the Quality of Dry Late Peaches of Leonforte
2015
The Late Peach of Leonforte [Prunus persica (L.) Batsch] grown in Southern Italy matures in September and October and as late as November. Fruits are wrapped in paper bags to protect them from parasites and are harvested only when fully ripe. Protected inside the bags, they ripen late and take on a bright yellow colour with red streaks. Highly aromatic, the peach has yellow, firm flesh that is high in soluble solids and has a distinctive, slightly caramelized flavour. The aim of this work was to deter¬mine the best method of drying peach as a means of conserving the fruit after harvest due to its very limited shelf-life. Drying processes were carried out in a pilot plant utilising differen…
Monoterpenes in grape juice and wines.
2000
The importance of monoterpenes on varietal flavour of wines has been reviewed. These compounds were mainly found linked to sugar moieties in the grape juice and wines, showing no olfactive characteristics. In this way, mechanisms to liberate terpenes were studied, making a comparative study between acidic and enzymic hydrolysis of terpene glycosides. Finally, analytical techniques developed to study these compounds, in both free or glycosidically forms, and also to fractionate glycosidic precursors, have been discussed.
Effects of tannin-containing diets on small ruminant meat quality
2010
Tannins are phenolic compounds present in several forages, tree leaves and by-products used for small ruminant feeding in the Mediterranean area. Although the effects of dietary tannins on small ruminant growth performances have been largely studied, only in the last ten years researchers have started to study the effects of tannins on meat quality. Meat from small ruminants given tanniniferous diets is lighter in colour compared to meat from animals given the same diets but in which the effects of tannins have been eliminated by the supplementation of polyethylene glycol. This result has been obtained with tannins from different feeds (carob pulp, acacia leaves or sulla fresh herbage). Rec…
Lipase-enhanced activity in flavour ester reactions by trapping enzyme conformers in the presence of interfaces
1998
In order to improve the lipase-catalyzed synthesis of flavour esters, we have used the reported strategy of interfacial activation-based molecular (bio)imprinting [Mingarro et al. 1995. Proc. Natl. Acad. Sci. U.S.A. 92: 3308], later called trapping in the presence of amphiphile interfaces (TPI) [Mingarro et al. 1996. Biochemistry 35: 9935]. Five lipases of fungal and mammalian origin typically used for esterification process have been explored to improve production by TPI treatment. A marked enhancement of enzymatic activity has been observed in all TPI-treated lipases assayed and the activation factor obtained was up to 90-fold. The dependence on chain length of acyl donors in the esterifi…
Inclusive photoproduction of bottom quarks for low and medium p T in the general-mass variable-flavour-number scheme
2016
We present predictions for b-quark production in photoprodcution and compare with experimental data from HERA. Our theoretical predictions are obtained at next-to-leading-order in the general-mass variable-flavor-number scheme, an approach which takes into account the finite mass of the b quarks. We use realistic evolved nonperturbative fragmentation functions obtained from fits to e+e- data. We find in general good agreement of data with both the GM-VFNS and the FFNS calculations, while the more precise ZEUS data seem to prefer the GM-VFNS predictions.
Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb–Pb collisions at √sNN = 2.76 TeV
2016
The elliptic flow, v2, of muons from heavy-flavour hadron decays at forward rapidity (2.5 < y < 4) is measured in Pb–Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee–Yang zeros methods are used. The dependence of the v2 of muons from heavy-flavour hadron decays on the collision centrality, in the range 0–40%, and on transverse momentum, pT, is studied in the interval 3 < pT < 10 GeV/c. A positive v2 is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10–20% and 20–40% centrality classes) for the pT interval from 3 to about 5 GeV/c with a significance larger than 3σ, ba…
Phenomenological applications in CP-violating systems in the SM and beyond
2019
El coneixement actual sobre l'estructura de la matèria és el resultat d'un enorme esforç experimental i teòric. El nostre Univers es compon de partícules elementals governades per les quatre forces fonamentals: gravitatòries, febles, electromagnètiques i fortes. El model estàndard (SM) de la física de partícules és la descripció teòrica més senzilla de com es relacionen aquestes partícules i forces, excepte la força gravitatòria. Al llarg dels anys, el SM ha estat capaç d'explicar totes les dades experimentals amb gran precisió, culminant en 2012 amb el descobriment del bosó de Higgs amb una massa de 125 GeV. La seua elegància, simplicitat i alta predictibilitat han convertit el SM en el mi…