Search results for "AROMA"

Powerful odorants in bovine, ovine, caprine and water buffalo milk determined by means of gas chromatography-olfactometry

1993

SummaryThe main compounds responsible for the aroma of bovine, ovine, caprine and water buffalo freshly secreted milk have been identified by means of a gas chromatography–olfactometry technique. Of the fourteen odour-active volatile compounds detected, eight were present in all milks studied. Ethylbutanoate and ethylhexanoate (fruit-like aroma), among the neutral odorants, were the major contributors to the odour of bovine, ovine and caprine milk. The aroma of water buffalo milk was less dependent on ethylhexanoate and was also due to l-octen-3-ol (aroma of raw mushrooms), nonanal (freshly cut grass), indole (stable, animals) and an unidentified constituent, characterized by a retention in…

Detection of powerful odorants in heated milk by use of extract dilution sniffing analysis

1994

SummaryThe odour impact compounds of raw, pasteurized and UHT bovine milk were investigated using vacuum extraction and extract dilution sniffing analysis using CharmAnalysis™. Fifteen odour peaks with Charm values between 10 and 3443 were detected. Of these peaks, twelve were identified as hexanal, ethyl butanoate, 2-heptanone, heptanal, dimethyl sulphone, l-octen-3-ol, ethyl hexanoate, 2-nonanone, nonanal, benzothiazole, 2-undecanone, indole and one as a mixture of 2-tridecanone and δ-decalactone. Dimethyl sulphone, indole and one unknown compound (retention index 1154) were the only ones detected as odour impact compounds in all three types of milk. Ethyl butanoate and ethyl hexanoate we…

Neutral volatile compounds in the raw milks from different species

1993

SummaryA comparative study was carried out on the flavour constituents of bovine, ovine, caprine and water buffalo fresh raw milks. The volatiles were isolated from milks by means of vacuum distillation and liquid–liquid extraction. Eighty neutral volatile compounds were identified using high resolution gas chromatography (HRGC) and HRGC-mass spectrometry. About 30 of these components have not been detected previously in milk. The volatiles in milk were similar for the four species, although several quantitative differences might explain the different odours. The volatiles consisted mainly of ethyl esters, especially those derived from butyric and hexanoic acids. Dimethylsulphone alone comp…

In-mouth aroma compound release during cheese consumption: Relationship with food bolus formation

2011

International audience; The present study describes the changes in mechanical properties and saliva incorporation for cheese samples with different composition and texture, and their influence on the rate of aroma release. Chewing work per cycle, salivary flow rate and chewing rate varied highly among subjects. Despite the differences in cheese hardness, at the end of mastication, bolus texture was the same for cheeses with the same lipid content. Low-fat cheeses gave harder bolus than high fat ones, despite being chewed longer, with higher work per cycle and more moisture. Salivary flow rate did not vary among cheese samples but, at the end of mastication, the amount of saliva in boluses d…

Effect of oxidoreduction potential on aroma biosynthesis by lactic acid bacteria in nonfat yogurt

2011

 ; The aim of this study was to investigate the effect of oxidoreduction potential (Eh) on the biosynthesis of aroma compounds by lactic acid bacteria in non-fat yogurt. The study was done with yogurts fermented by Lactobacillus bulgaricus and Streptococcus thermophilus. The Eh was modified by the application of different gaseous conditions (air, nitrogen, and nitrogen/hydrogen). Acetaldehyde, dimethyl sulfide, diacetyl, and pentane-2,3-dione, as the major endogenous odorant compounds of yogurt, were chosen as tracers for the biosynthesis of aroma compounds by lactic acid bacteria. Oxidative conditions favored the production of acetaldehyde, dimethyl sulfide, and diketones (diacetyl and pen…

Production of a cheese model for sensory evaluation of flavour compounds

1995

Summary - A cheese model used to perform sensory evaluation of flavour compounds extracted from various cheese varieties was made with caseins, low heat milk powder, deodorized milk fat, NaCI and renne!. Its composition and physicochemical properties were close to mature hard cheese, apart from a lower dry matter content and sodium concentration, and a higher lactose concentration. Its preparation was established in arder to avoid drainage for at least 24 h, which should allow the incorporation of not only sorne lipophilic substances such as aromas but also some water-soluble substances such as amino acids and peptides. The rheological behaviour of the cheese model measured by a compression…

A study on texture-taste-aroma interactions: physico-chemical and cognitive mechanisms

2009

International audience; Texture–taste, texture–aroma and aroma–taste interactions were examined in custard desserts varying in viscosity (at identical composition), sucrose level and aroma nature. All reciprocal interactions were investigated, with each binary interaction addressed through an independent sensory study. Rheological, in vivo aroma release and sucrose release measurements were run in parallel to control for a possible physico-chemical origin of these interactions. Observed interactions were found to be dependent upon the nature of the sensory modalities involved; physico-chemical mechanisms could only in some instances entirely explain these interactions. Taste and aroma did n…

Inactivation of lactococcal aromatic aminotransferase prevents the formation of flora aroma compounds from aromatic amino acids in semi-hard cheese

1999

The enzymatic conversion of aromatic amino acids to aroma compounds plays a role in the formation of an undesirable floral aroma in Cheddar-like cheeses. In lactococci, the first step of aromatic amino acid degradation is a transamination, catalysed by an aromatic aminotransferase (AraT). We observed previously that in vitro, araT inactivation prevented degradation of aromatic amino acids and decreased degradation of Met and Leu. In this study we evaluated the effect of araT inactivation in Lactococcus lactis on flavour development in St. Paulin-type cheese. The degradation of amino acids was monitored by using radiolabelled amino acids and the volatile compounds formed were analysed by GC-…

Aroma cross-modal interactions with texture and taste in dairy products

2006

L'arôme du gin : identification des composés clés et rôle des matières premières

2012

Le texte intégral de cette thèse est confidentiel à durée indéfinie.; Afin d’identifier les composés responsables de l’arôme du gin, une procédure GC-O-MS se basant sur la fréquence de détection a été développée. Elle a permis de déterminer l’intensité odorante des composés volatils. Leur qualité d’odeur a pu être définie par le développement d’une roue des odeurs utilisée pour catégoriser les descripteurs obtenus. Cette approche nous a dans un premier temps permis d’identifier les composés potentiellement importants pour l’arôme du gin. L’origine de ces composés a ensuite été déterminée par l’étude de la fraction volatile de différents « botanicals » appartenant à la recette du gin. Cette …