J L Le Quéré

French National Research Institute for Agriculture, Food and Environment (INRAE)

Perception of flavor is a dynamic process during which the concentration of aroma molecules at the olfactory epithelium varies with time as they are released progressively from the food in the mouth during consumption. The release kinetics depends on the food matrix itself but also on food oral processing, such as mastication behavior and food bolu...

Perception of flavor is a dynamic process during which the concentration of aroma molecules at the olfactory epithelium varies with time as they are released progressively from the food in the mouth during consumption. The release kinetics depends on the food matrix itself, but also on food oral processing, such as mastication behavior and food bol...

Proton Transfer Reaction‐Time‐of‐Flight‐ Mass Spectrometry (PTR‐ToF‐MS) is an analytical chemistry technique that can be used for measuring the concentration of volatile organic compounds directly in the subjects’ noses (nosespace, in vivo analysis) during a tasting and over time. It can be combined with temporal sensory methods such as Temporal Do...

Within the peripheral olfactory process, odorant metabolizing enzymes are involved in the active biotransformation of odorants, thus influencing the intensity and quality of the signal, but little evidence exists in humans. Here, we characterized the fast nasal metabolism of the food aroma pentane-2,3-dione in vivo and identified two resulting meta...

Proceedings of the 16th Weurman Flavour Research Symposium

Since 1975, the Weurman Flavour Research Symposium has been held every three years in different European countries, and has been finally established as an international event that offers unique opportunities for distinguished scientists from academia and industry, from different disciplines, and from all over the world, to discuss trends and new pa...

The flavour of food, commonly called ‘taste’, is an essential determinant of food choice by the consumer. Flavour perception in the mouth results from at least two sensory modalities, aroma and taste, due to odour-active and taste-active compounds released from the food matrix on eating. Instrumental assessment of flavour should characterise odouri...

Proceedings of the 16th Weurman Flavour Research Symposium, held online in May 2021.

Addition of oenological tannins claims to have a positive impact on wine stability, protection from oxidation and likely sensory persistence. However, their role on red wine aroma during oxidation is controversial. The present study aims at investigating the effect of addition of oenological tannins on wine flavour (mainly aroma) before and after a...

The headspace volatile organic compound (VOC) fingerprints (volatilome) of French wine brandies were investigated by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS). Protonated ethanol chemical ionization was used with dedicated experimental conditions that were previously validated for model wines. These included a reference...

The 16th Weurman Flavour Research Symposium will be ONLINE May 4-6, 2021 Registration now open ! https://symposium.inrae.fr/weurman2020/Registration

The present study aims at developing an analytical methodology which allows correlating sensory poles of chocolate to their chemical characteristics and, eventually, to those of the cocoa beans used for its preparation. Trained panelists investigated several samples of chocolate, and they divided them into four sensorial poles (characterized by 36...

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates' headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory cat...

Perception of cheese flavor is due to the combined detection of aroma and taste compounds present in cheese by their respective sensory receptors. This article describes the analytical methodologies available to extract and characterize the volatile and nonvolatile compounds responsible for aroma and taste, respectively, from a cheese matrix. It em...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Odorant-metabolizing enzymes are critically involved in the clearance of odorant molecules from the environment of the nasal neuro-olfactory tissue to maintain the sensitivity of olfactory detection. Odorant metabolism may also generate metabolites in situ, the characterization and function of which in olfaction remain largely unknown. Here, we eng...

Ahhhh chocolate! Who doesn't love chocolate? The analysis of volatile organic compounds (VOCs) emanating from environment, plants, food or food ingredients has been the basis for many studies aiming at categorizing samples or sites. For this purpose, global VOCs profiles may be used as fingerprints of the samples, sometimes referred to as “volatilo...

Direct‐injection mass spectrometry (DIMS) techniques have evolved into powerful methods to analyse volatile organic compounds (VOCs) without the need of chromatographic separation. Combined to chemometrics, they have been used in many domains to solve samples categorization issues based on volatilome determination. In this paper, different DIMS met...

15. Weurman Flavour Research Symposium ; Graz (Autriche) - (2017-09-18 - 2017-09-22)

Great inter-individual differences exist in fat perception. Forty subjects were grouped according their global fat perception in cottage cheeses. The more sensitive subjects were also more sensitive to fatty odorants, they had a higher respiratory flow and thus a higher rate of release of aroma compounds in the nasal cavity, which could explain the...

With proton transfer reaction-mass spectrometry standard operating conditions, analysis of alcoholic beverages is an analytical challenge. Ethanol reacts with the primary ion H3O⁺ leading to its depletion and to formation of ethanol-related ions and clusters, resulting in unstable ionization and in significant fragmentation of analytes. Different m...

Lactating female rabbits emit in their milk an odorant, the mammary pheromone (MP; 2-methylbut-2-enal), which elicits orocephalic “searching-grasping” movements in newborns and helps them to find the nipples and suck. Rapid responsiveness to the MP is crucial for the pups since the mother is nursing briefly (5 min) and only once per day. It is then...

Lactating female rabbits emit in their milk an odorant, the mammary pheromone (MP; 2-methylbut-2-enal), which elicits orocephalic “searching-grasping” movements in newborns and helps them to find the nipples and suck. Rapid responsiveness to the MP is crucial for the pups since the mother is nursing briefly (5 min) and only once per day. It is then...

There is a growing interest in developing low-fat products in response to increased consumer demand. However, fat reduction often leads to low sensory acceptability by consumers. The identification of the sensory characteristics impacted by the reduction of fat is a first step to choose the most appropriate strategy to offset the adverse effects of...

Freshly-distilled French wine brandies were evaluated by gas chromatography-olfactometry (GC-O). Six brandy samples were studied, coming from two growth areas, both belonging to the same limited geographic zone, which is a homogeneous vineyard area. The GC-O methodology, using detection frequency analysis, revealed 88 olfactive areas (OAs) for whic...

It has been evidenced that olfactory mucosa (OM) can metabolize inhaled odorous volatile organic compounds (VOCs) through various enzymatic activities. Moreover, it has been hypothesized that the resulting metabolites could be implied in overall aroma sensory perception. The purpose of the present study was to develop a continuous on-line method al...

Olfactory mucosa (OM) can metabolise odorant volatile organic compounds through various enzymatic mechanisms to produce odorous or non-odorous metabolites. Preliminary ex vivo studies using headspace-gas chromatography (HS-GC) revealed the formation of metabolites when odorant molecules were injected in the headspace above a fresh explant of rat ol...

It has been evidenced that olfactory mucosa (OM) can metabolize inhaled odorous volatile organic compounds (VOCs) through various enzymatic activities. Moreover, it has been hypothesized that the resulting metabolites could be implied in overall aroma sensory perception. The purpose of the present study was to develop a continuous on-line method al...

It has been evidenced that olfactory mucosa can metabolize inhaled odorous volatile organic compounds (VOCs) through various enzymatic mechanisms [1]. Moreover, it has been hypothesized that the formed metabolites could be implied in overall aroma sensory perception. Thus, using headspace gas chromatography (HS-GC) [2], preliminary ex-vivo studies...

ISOEN 2015 Symposium Proceedings

Wine brandy young spirits were evaluated by gas chromatography-olfactometry (GC-O) in order to investigate potential differences between samples according to their growth area. Six spirits were studied using the detection frequency method. The odour events generated by the panel were grouped into 94 olfactive areas (OAs). Correspondence analyses we...

The paper reports a research in which sixteen untrained subjects did a temporal dominance of sensations (TDS) evaluation of three commercial flavoured fresh cheeses in duplicate while the aromas released in their nose were simultaneously collected by a proton transfer reaction – time-of-flight mass spectrometer (PTR-ToF-MS). A new way of analysing...

An atmospheric pressure chemical ionization ion-trap mass spectrometer was set up for the on-line analysis of aroma compounds. This instrument, which has been successfully employed for some years in several in vitro and in vivo flavour release studies, is described for the first time in detail. The ion source was fashioned from polyether ether keto...

It has been evidenced that olfactory mucosa can metabolize inhaled odorous volatile organic compounds (VOCs) through various enzymatic mechanisms [1]. Moreover, it has been hypothesized that the formed metabolites could be implied in overall aroma sensory perception. Thus, using headspace gas chromatography (HS-GC) [2], preliminary ex-vivo studies...

Instrumental assessment of the flavour of dairy foods includes analyses of volatile compounds responsible for aroma, non-volatile compounds responsible for taste, and components perceived as mouthfeel and texture. The first part of this chapter is devoted to instrumental methods used to identify key aroma compounds that contribute significantly to...

Experiencing beer involves multiple senses. Color, clarity (the lack of turbidity) and foam (volume, duration and cling) are perceived visually. The temperature, carbon dioxide bite and astringency are tactile (chemesthetic) sensations. Various tastes are perceived in the mouth. Odors are perceived, either orthonasally or retronasally, by a huge nu...

The potentiality of solid-state 31P nuclear magnetic resonance (NMR) to determine in a non-destructive way the different states of phosphates in cheeses was examined. Sixteen semi-hard cheeses of various compositions were studied, and three fractions of phosphates (P) were distinguished according to their mobility: (1) mobile soluble P (ca. 10 % of...

For the on‐line monitoring of flavour compound release, atmospheric pressure chemical ionization (APCI) and proton transfer reaction (PTR) combined to mass spectrometry (MS) are the most often used ionization technologies. APCI‐MS was questioned for the quantification of volatiles in complex mixtures, but direct comparisons of APCI and PTR techniqu...

Livre ISBN-13 : 978-3-902811-91-2

Livre ISBN-13 : 978-3-902811-91-2

The aim of this work was to compare detection and fragmentation patterns of aroma compounds obtained with three different precursor ions and several E/N source parameter values with the proton transfer reaction (PTR-MS) methodology. The reactant ions H3O+, NO+ and O2+. were generated in a Switchable Reagent Ions (SRI) source of a PTR-ToF-MS (Ionico...

Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) or proton transfer reaction mass spectrometry (PTR-MS) has been in use frequently for in vivo aroma release studies. In APCI-MS, protonated water clusters formed from moisture in the expired air are used as reagent ions. Yet the influence of a change in relative water content in t...

Gas Chromatography-Olfactometry (GC-O) is a technique that lies halfway between physicochemical and sensory analysis and involves the perception of volatile flavour compounds, separated by gas chromatography, by the human nose. Of the different GC-O procedures available, detection frequency has been proved to be more rapid and more repeatable, even...

A great need exists for valuable information on factors affecting the quality of animal related products. The second edition of Handbook of Meat, Poultry and Seafood Quality, focuses exclusively on quality aspects of products of animal origin, in depth discussions and recent developments in beef, pork, poultry, and seafood quality, updated sensory...

Perception of cheese flavor is due to the combined detection of aroma and taste compounds present in cheese by their respective sensory receptors. This article describes the analytical methodologies available to extract and characterize the volatile and nonvolatile compounds responsible for aroma and taste, respectively, from a cheese matrix. It em...

We investigated the role of both candy texture and eating technique (melting or chewing) on the dynamics of aroma release. One novelty of this type of analysis was the simultaneous application of instrumental and sensory analysis. Four candy textures were established based on their storage modulus at 1 Hz by varying the gelatine content between 0 a...

IntroductionSorptive Extraction Methods Dynamic Methods in Flavor AnalysisGlobal and Fast Analysis of FlavorConclusions References

IntroductionCharacterization of Aroma (Volatiles)GCDynamic Methods in Flavor AnalysisGlobal and Fast Assessment of FlavorReferences

Acting as chemical messengers for olfactory cells, food flavor materials are organic compounds that give off a strong, typically pleasant smells. Handbook of Fruit and Vegetable Flavors explores the flavor science and technology of fruits and vegetables, spices, and oils by first introducing specific flavors and their commercialization, then detail...

The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P S...

26e Congrès de la Société Française d'Electrophorèse et d'Analyse Protéomique ; 26e Journées Françaises de la Spectrométrie de Masse ; SMAP = Spectrométrie de Masse et Analyse Protéomique

(23)Na NMR spectroscopy has been used to study the effects of Na(+) ion concentrations on the structure of 1% (w/w) iota-carrageenan systems, a natural gelling polysaccharide used as a thickener in the food industry. Rheological and (23)Na T(1) relaxation time measurements revealed that gel formation correlates with decreases in ion mobility over t...

In hard cooked cheeses, any interactions between the thermophilic starters as they grow during the cheese-making are critical, since they modify bacterial growth kinetics and acidification kinetics, so affecting the ripening process and the final characteristics of the cheese. Twenty-four experimental hard cooked cheeses were made under controlled...

Multiphasic models of stirred fruit yoghurts made from a bilayer that consisted of a pectin and a dairy gel were developed in order to study the transfer of strawberry flavour compounds between the two phases. Several parameters (i.e., the flavour concentration, the fat content of the dairy gel and the storage temperature) affecting flavour compoun...

Recent developments in techniques used for flavor measurements include sorptive extraction methods, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), and headspace sorptive extraction (HSSE). Sensory information can be obtained by combining gas chromatography with olfactometry (GC-O). Recent developments in dynamic instrument...

The transfer of small analytes in a multiphasic stirred fruit yoghurt model, made of a pectin gel aimed to mimic fruit pieces and of a dairy gel done with milk acidified by glucono-δ-lactone hydrolysis, have been studied. The concentration gradients between the pectin gel and the dairy gel were the driving force for the migration of small analytes...

In Leucophaea maderae, male calling behavior involves the release of a sex pheromone from the abdominal sternal glands. An extract of sternal glands attracted conspecific females over a distance. The compounds present were identified as hydroxy-3-butan-2-one, (2R, 3R)-butanediol, senecioic acid, and (E)-2-octenoic acid. The same components are also...

Interactions between five aroma compounds (β-ionone, α-ionone, γ-decalactone, 2-nonanone and eugenol) with β-lactoglobulin in its monomeric state have been investigated by 2-Dimensional TOCSY 1H NMR using the chemical shift change method. The comparison of amino acid chemical shifts of the protein alone and of each protein-flavour complex in identi...

A new APCI source and interface connected to an ion trap mass spectrometer have been designed in order to allow introduction and analysis of a gaseous flow within the source. In vitro detection limits, linear response ranges and repeatability (daily and day-to-day) have been determined for a set of flavour molecules of various chemical classes. Det...

Flavour release during eating of a food depends upon many parameters that can hardly be managed. In-vivo measurements by the APCI MS-nose method allowed temporal sensory evaluation and flavour release data to be directly correlated, but several limitations have frequently been reported. These were: high inter-individual variability, low repeatabili...

Model matrices consisting of a pectin and a dairy gel were investigated to study the transfer of flavour compounds between the different phases of stirred fruit yoghurt. Using a full factorial experimental design, different parameters (storage temperature, initial flavour concentration in the pectin gel and fat content of the dairy gel) were studie...

Relating flavour (aroma and taste) compounds to flavour perception experienced by a consumer is still a challege for the flavour research. The aim of the present study was to determine to what extent the food matrix texture influences the in vivo release of aroma and taste compounds. Sodium release and salty perception were evaluated using four che...

Gas chromatography/infrared (GC/IR) spectroscopy coupling combines the separation power of high-resolution gas chromatography (HRGC) to the highly specific identification technique, infrared (IR) spectroscopy, based on the absorption of IR radiation by the molecules. Relying on different molecular properties, IR is an excellent complement to mass s...

Release of strawberry flavour compounds at vapour/matrix interfaces was studied in model food systems simulating a yoghurt with a fruit preparation syrup. The effect of different parameters including physicochemical characteristics of the flavour compound, the structure and composition of the matrix and the temperature (4 and 10°C) on the release o...

In order to study differences in -decalactone production in yeast, four species of Sporidiobolus were cultivated with 5% of methyl ricinoleate as the lactone substrate. In vivo studies showed different time courses of intermediates of ricinoleic acid breakdown between the four species. In vitro studies of the β-oxidation system were conducted with...

Due to their high adsorbing capacity, different solids (carbonaceous adsorbents, zeolites, and polymers) are used to extract and concentrate aroma compounds from foods. Adsorption mechanisms are described in two phases, a kinetic stage that involves the diffusion of the analytes within the adsorbent pores and a thermodynamic stage that can be descr...

During cheese ripening, migration phenomena and release of potentially taste-active compounds are responsible for the evolution of sourness, saltiness and bitterness which are the main cheese gustatory characteristics. Moreover, these basic tastes are also influenced by the structure of the matrix that changes during ripening. Correlations between...

This chapter discusses instrumental techniques to analyze cheese flavor. It focuses on recent advances made to study and identify the taste-active components present in the water-soluble fraction of cheese. A general procedure for the preparation of fractions involves an extraction of grated cheese by water followed by a fractionation scheme, gener...

The present study aims to investigate the relationships between perception, flavor release and oral parameters during the eating of a model cheese. A modified time–intensity (T–I) methodology, consisting in monitoring several attributes at several times over the same mastication, was used to evaluate temporal perception. A visual calibration with g...

The objective of this work was to study the putative interactions between flavour compounds and coffee melanoidins. After extraction, melanoidins were freeze-dried and several flavour compounds from different chemical classes were tested in aqueous solution. The retention of flavour compounds by melanoidins was found to be different in function of...

This study aims to follow the kinetics of aroma compound release during model cheese consumption in order to clarify the relationships between flavor release and some oral parameters. Eight subjects participated in the study. Breathing, salivation, chewing, and swallowing were monitored during the eating process. Temporal nosespace analyses were pe...

This study deals with the release kinetics of nonvolatile compounds (NVC) (leucine, phenylalanine, glutamic acid, citric acid, lactic acid, propanoic acid, sodium, potassium, calcium, magnesium, chloride, and phosphates) during the eating of a model cheese and the relationships to some oral (salivary and masticatory) parameters. The aroma release h...

A two-step strategy to select food samples presenting defined flavor characteristics was developed and applied to the selection of wines with a berry flavor. A sorting test was conducted on a large number of samples with an inexperienced jury. It was followed by a qualitative descriptive analysis of the wines selected during sorting conducted with...