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International audience; The aim of this study was to investigate the impact of oral impairment on chewing behaviour, food bolus properties and food comfortability during elderly consumption of model cheeses. Seventy-two elderly persons (aged 66 to 88) was recruited and classified into two groups according to dental status (poor vs. satisfactory). They showed a wide range of salivary flow rates whatever their dental status (stimulated: 0.2-3.8 mL min-1, resting: 0.1-0.8 mL min-1). Standardized bites of four model cheeses with an identical composition but different textures (soft, hard, processed and whipped) were tested. The time and number of chewing cycles required to form a bolus were measured. The rheological properties of the bolus were studied, as was saliva moistening. Food comfortability was assessed by means of a questionnaire composed of 5 sections (1-oral comfort, 2-bolus formation, 3-pain, 4-texture and 5-flavour perception). The chewing parameters measured were not modified by the oral health. However, elderly with poor dentition formed harder boluses than elderly with satisfactory dentition. Moreover, for elderly with poor dentition, the quantity of saliva incorporated into the bolus was correlated with the stimulated salivary flow rate, which was not the case for elderly with satisfactory dentition. General oral comfort and its different attributes were poorly associated with the oral health of the elderly. A multifactorial analysis performed on an average cheese showed that food comfortability is independent of changes in the hardness and moistening of the bolus, regardless of dental status. In particular, poor dental status increases the hardness of the bolus without modifying its comfortability.

International audience; In humans, oral food intake is the ultimate stage of food supply chain and the beginning of food disintegration and digestion process. During aging, the oral health changes and sometimes eating food can be a real challenge as food can be hard to masticate, humidify or swallow. To meet this challenge, and as part of the AlimaSSenS project, a team of researchers from the Centre of taste and eating behaviour investigated the concept of “oral comfort” when eating a food in an elderly population. A group of 107 seniors aged 65 years and more participated in qualitative (focus group) and quantitative studies (tasting sessions) in order to explore the concept of oral comfort when eating, according to elderly people, and develop a questionnaire to evaluate the oral comfort when eating a food product. The results of the study highlighted that oral comfort when eating a food product is a multi-dimensional concept, which includes dimensions related to food oral processing, food sensory properties and, to a lesser extent, pain sensation. The concept of oral comfort when eating food should be taken into account by those who are willing to design food products tailored to the elderly population.; Chez l’homme, la mise en bouche d’un aliment est l’étape ultime de la chaîne alimentaire et le début du processus de dégradation et de digestion. Avec l’âge, la santé orale évolue et peut parfois rendre l’acte alimentaire difficile. Dans le cadre du projet AlimaSSenS, 107 personnes âgées ont participé à des études qualitatives (groupes de discussion) et quantitatives (séances de dégustation) afin de comprendre ce qu’est le confort en bouche et de développer un outil permettant d’évaluer ce concept. Les résultats de cette étude ont montré que le confort en bouche est un concept multidimensionnel qui inclut des dimensions de formation de bol alimentaire, de propriétés sensorielles de l’aliment et, dans une moindre mesure, de douleurs ressenties en bouche. De plus, cette étude a montré qu’un aliment inconfortable l’est pour l’ensemble des seniors interrogés, quelle que soit leur santé bucco-dentaire. Il semble essentiel, lors de développement de nouveaux produits à destination de la population senior, de recueillir l’évaluation du confort en bouche desdits produits avant toute commercialisation.

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&rsquo, headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi&sup2, test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.

International audience; 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 different descriptors) attributable to chocolate flavor. The same samples were analyzed by six different techniques: Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), Solid Phase Micro Extraction-Gas Chromatography-Mass Spectroscopy (SPME-GC-MS), High-Performance Liquid Chromatography (HPLC) (for the quantification of eight organic acids), Ultra High Performance Liquid Chromatography coupled to triple-quadrupole Mass Spectrometry (UHPLC-QqQ-MS) for polyphenol quantification, 3D front face fluorescence Spectroscopy and Near Infrared Spectroscopy (NIRS). A multi-block classification approach (Sequential and Orthogonalized-Partial Least Squares – SO-PLS) has been used, in order to exploit the chemical information to predict the sensorial poles of samples. Among thirty-one test samples, only two were misclassified.

Food consumption is by far the most important point where food's organoleptic properties can be perceived and can elicit sensory pleasure. Ageing is often accompanied by oral impairments. Those impairments may impact food perception by changing texture perception and the release of flavor components, which have a significant impact on food acceptability. The present study aimed at evaluating the impact of oral health on the perception of food comfortability in an elderly population. This was achieved by asking elderly people with a good oral health and elderly people with poor oral health to rate six cereal products and six meat products using a food comfortability questionnaire. Thirty-seven and 35 elderly people (65–87 years old) underwent either a cereal or meat session, respectively. The present study showed very few effects of dental and saliva status on food perception. For the cereal products, a significant effect of dental status was observed for one texture descriptor and one flavor descriptor, and a significant effect of salivary status was observed for two texture descriptors and one flavor descriptor. For the meat products, a significant effect of dental status and a significant effect of salivary status were observed on one flavor descriptor. For both products, no significant impact of dental or salivary status was observed on the general perception of food oral comfort nor on food bolus formation. Future studies exploring the impact of a broader set of oral parameters and potential adapting factors are needed to further explore the results of the present study. Practical applications During oral food consumption, mastication, salivation, and swallowing play a key role in the acceptance of food and beverages by modulating the perception of texture, taste, and aroma, as well as providing eating comfort by assisting the food breakdown process into a bolus that can be safely swallowed. The age-related oral impairments such as loss of teeth, decrease in salivary flow or dysphagia are known to have an impact on food consumption. However, very few products are developed to skirt those impairments. Therefore, in the context of an ageing population, there is a need to develop functional foods that meet the specific nutritional needs of the elderly population, as well as a well-balanced flavor and texture framework. Considering the large interindividual variability observed on the elderly people, developing adapted functional foods is a major challenge for the food industry and society.

This study has been financially supported by the French National Research Agency-ANR (AlimaSSenS project No. 14-CE20-0003-01). The NutriNet-Sante is supported by the French Ministry of Health (DGS), the French Institute for Health Surveillance (InVS), the National Institute for Prevention and Health Education (INPES), the Foundation for Medical Research (FRM), the National Institute for Health and Medical Research (INSERM), the National Institute for Agricultural Research (INRA), the National Conservatory of Arts and Crafts (CNAM), and the University of Paris 13; International audience; Food processing impacts both food structure and nutritional density. The effect of food structure on satiety and glycemic potentials is well recognized. However, the association between processing, satiety and glycemic potentials and nutrient profiles has not been much studied, especially in the diets of the elderly. Therefore, this study aimed at exploring relations between the level of food processing, consumption and nutrient profiles and satiety and glycemic potentials among 6686 French elderly people (≥65 years). Dietary assessment was realized through a web-based 24 h dietary record tool. Among a total of 2688 foods, 280 generic foods were aggregated based on a consumption threshold of at least 5% by the population. The satiety potential was calculated using the Fullness Factor equation, and the glycemic potential using the glycemic index and the glucose glycemic equivalent. Foods and dishes were ranked according to an adapted international NOVA classification as raw/minimally-processed (G1), processed (G2) and ultra-processed (G3). ANOVA and correlation analyses showed that the more food is processed, the lower its satiety potential and nutrient density and the higher its glycemic impact, especially when comparing G1 and G3. Besides, the foods consumed in the greatest quantity daily tend to be the most satiating, and ultra-processed foods were among the less frequently consumed both in terms of percentage and daily quantity (around two-fold difference between minimally- and ultra-processed foods). In conclusion, because it is partly related to health food potential, the degree of processing, especially for ultra-processed products, should be taken into consideration more when evaluating consumption profiles of different populations.

In humans, oral food consumption is by far the most important point where food's organoleptic properties can be perceived and can elicit sensory pleasure. It is also the ultimate stage of the food supply chain and the beginning of the food disintegration and digestion process. However, in regard to the influence of ageing on food oral processing, this topic has been mainly investigating through mastication, whereas salivation remains largely unexplored. The present experiment aimed at studying the impact of normal ageing on salivary flow taking into account the dental status and the number of drugs taken by the elderly people. This was achieved by comparing resting and stimulated salivary flows of young versus healthy elderly adults (i.e., autonomous elderly people without acute pathology). Ninety-three young adults (22-55 years old) and 84 elderly people (70-92 years old) underwent a measurement of resting and stimulated salivary flows and an oral examination (teeth counting; functional unit counting i.e., counting occluding tooth pairs). The present study showed an average 38.5% reduction of resting salivary flow and 38.0% reduction of stimulated salivary flow in healthy elderly people compared to young adults. This reduction was observed independently of the dental status and drug intake: elderly people presented reduced salivary flow even if they did not take any drugs or if their dental status was similar to the one of the young adults. The results also highlight a large inter-individual variability both in young and elderly adults. PRACTICAL APPLICATIONS During oral food consumption, saliva plays a key role in the acceptance of food and beverage by modulating the perception of texture, taste and aroma, as well as providing eating comfort by assisting the food breakdown process into a bolus that can be safely swallowed. However, in regard to the influence of ageing on food oral processing, the present results demonstrate a reduced salivary flow in healthy elderly people. Consequently, there is a need for developing foods tailored to the salivary capacities of elderly people aside from the efforts put into the development of foods tailored to the mastication and swallowing abilities of this population. In fact, in the context of an ageing population, the development of products meeting an elderly person's functional capacities becomes a major challenge for the food industry as well as for society.

National audience; Introduction et but de l'étude : Chez l'homme, la mise en bouche d'un aliment est le début du processus de dégradation et de digestion. Avec l'âge, la santé orale évolue. Un aliment difficile à mâcher, à humidifier ou avaler rend l'acte alimentaire difficile. L'objectif de cette étude est de déterminer le rôle des différents facteurs de santé orale (état dentaire, flux salivaire, force musculaire) sur les dimensions physiologiques (faculté à former un bol alimentaire, libération et perception de la flaveur) et/ou sur la prise alimentaire et la corpulence des séniors. Matériel et méthodes : 61 séniors (>65 ans) vivant à domicile et ne présentant pas de pathologie chronique ont été recrutés (âge = 72 ± 5 ; 31F ; 30H) et caractérisés sur la base des dimensions suivantes : - Santé orale via un examen clinique (flux salivaire au repos et stimulé, viscosité salivaire, nombre de dents, nombre d'unités fonctionnelles, force musculaire de la langue) - Auto-évaluation de la santé orale (GOHAI, xérostomie) - Perceptions sensorielles (détection des saveurs et des odeurs) - Mécanismes en bouche (faculté à former un bol de carotte, libération d'arômes) - Variables nutritionnelles (enquête alimentaire de 5 jours) - Corpulence (impédance, IMC) Les analyses statistiques ont été faites par Partial Least Square-Path Modeling. Le protocole a été approuvé par le CPP Est-1 N° IRB 2016-A00916-45. Résultats et Analyse statistique : Les résultats montrent que les personnes qui ont un flux salivaire élevé libèrent davantage d'arômes en bouche (r = 0.27 ; p < 0.05) et consomment plus de calories et de protéines que les autres (r = 0.31 ; p < 0.05). Les personnes ayant une bonne santé dentaire s'estiment en meilleure santé orale et ont une meilleure faculté que les autres à former un bol de carotte déglutissable (r =0.51 ; p < 0.001 et r =0.56 ; p < 0.01 respectivement). En revanche, l'état dentaire n'influence pas les prises énergétique et protéique. Enfin, les personnes ayant une faible force musculaire de la langue ont une consommation énergétique et protéique plus élevée que les autres (r = -0.18 ; p < 0.05). De plus, une meilleure perception des composés de la flaveur diminue la consommation d'énergie et de protéines (r = -0.40 ; p < 0.01). Finalement, plus les prises calorique et protéique sont élevées, plus la corpulence des personnes âgées est élevée (r = 0.35 ; p < 0.01). Conclusion : Cette étude montre que les facteurs de santé orale (dentition, salivation, force musculaire) jouent des rôles différents dans les processus de mastication et de prise alimentaire chez les personnes âgées. Ces résultats permettront de développer une offre alimentaire adaptée aux différents comportements alimentaires induits par les troubles.

International audience; Several studies demonstrated that oral health impairment, such as tooth loss or a decrease in salivary flow might lead elderly people to reduce their meat intake. The present study assessed the impact of culinary processes liable to improve meat texture and smooth down meat oral processing, in order to fulfil the oral capacities of elderly people. Four culinary processes were selected: cooking bag, blade tenderizer, marinade and low-temperature cooking. A panel of 40 elderly participants with good and poor dental status were asked to assess 5 chicken breast samples, 5 roast beef samples and 4 beefsteak samples prepared according to different process conditions by using an “oral comfort” questionnaire. Results highlighted the fact that oral impairment may alter food bolus formation as well as texture perception while eating meat in elderly people. Furthermore, they revealed that easy-to-do culinary processes may improve meat tenderness and juiciness as well as smooth down food bolus formation, in particular for the roast beef.

Introduction et but de l’etude Le vieillissement peut s’accompagner d’une baisse du flux salivaire et du nombre de dents entrainant une moindre consommation de viande avec un risque de denutrition et de fonte musculaire. Ainsi, pour augmenter la consommation de proteines chez les seniors, il est important de proposer des aliments carnes adaptes a leurs capacites orales. Dans ce contexte, le but de ce travail est d’objectiver le confort en bouche lors de la prise d’aliments developpes specifiquement chez deux populations seniors a l’etat buccodentaire contraste. Materiel et methodes Deux groupes de sujets (> 65 ans et vivant a domicile), 36 (18H, 18F) presentant une bonne dentition (BD, âge = 73 ± 5, UFP (unites fonctionnelles posterieures)= 8 ± 1) et 36 (15H, 21F) une mauvaise dentition (MD, âge = 74 ± 5, UFP = 3 ± 1) ont ete choisis. Les deux groupes sont sans risque de denutrition (MNA = 27,4 ± 0,3). Ils ont un flux salivaire stimule (FSS) non different entre BD et MD et de moyenne globale 1,8 ± 0,7 mL/min. Deux matrices, bœuf (Bo) et poulet (Po), elaborees selon un meme procede, ont ete evaluees (bouchee de 6 g) deux fois au moyen d’un questionnaire sensoriel divise en 5 parties [1] , [2] : confort en bouche et facilite a manger, facilite a former un bol, douleurs ressenties, texture et flaveur. Les donnees ont ete traitees par ANCOVA (2 facteurs categoriels [(Bo, Po) et (BD, MD)] + 1 facteur continu [FSS]). Resultats et analyse statistique Exprimes sur une echelle de 0 a 100, les resultats montrent que les sujets MD jugent les 2 matrices plus confortables en bouche que les sujets BD (75 ± 1,8 et 71 ± 1,8, F = 6,1, p La comparaison entre les matrices souligne que Po est juge plus confortable que Bo (77 ± 1,8 et 68 ± 1,8, F = 10,7, p Il n’y a pas d’effet significatif du FSS sur l’evaluation du confort. Conclusion Le resultat remarquable de cette etude est que les sujets avec un mauvais etat bucco-dentaire jugent les produits plus confortables et plus faciles a manger que les sujets normo-dentes. Globalement, les procedes de fabrication permettent d’obtenir deux viandes confortables en bouche, la matrice de poulet etant jugee encore plus confortable que celle de bœuf. La suite de ce travail portera sur les caracteristiques structurales et biochimiques du bol alimentaire forme par la mastication pour ces deux groupes de seniors et sur leur lien avec la perception du confort et la digestibilite des deux matrices carnees.

International audience; 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 sample categorization issues based on volatilome determination. In this paper, different DIMS methods that have largely outperformed conventional electronic noses (e-noses) in classification tasks are briefly reviewed, with an emphasis on food-related applications. A particular attention is paid to proton transfer reaction mass spectrometry (PTR-MS), and many results obtained using the powerful PTR-time of flight-MS (PTR-ToF-MS) instrument are reviewed. Data analysis and feature selection issues are also summarized and discussed. As a case study, a challenging problem of classification of dark chocolates that has been previously assessed by sensory evaluation in four distinct categories is presented. The VOC profiles of a set of 206 chocolate samples classified in the four sensory categories were analysed by PTR-ToF-MS. A supervised multivariate data analysis based on partial least squares regression-discriminant analysis allowed the construction of a classification model that showed excellent prediction capability: 97% of a test set of 62 samples were correctly predicted in the sensory categories. Tentative identification of ions aided characterisation of chocolate classes. Variable selection using dedicated methods pinpointed some volatile compounds important for the discrimination of the chocolates. Among them, the CovSel method was used for the first time on PTR-MS data resulting in a selection of 10 features that allowed a good prediction to be achieved. Finally, challenges and future needs in the field are discussed.

International audience; In the elderly population, ageing frequently impacts on the different aspects of oral physiology that play a key role in eating behavior. In the context of an aging population, it is crucial to develop a food supply tailored for the elderly people in order to prevent the onset of malnutrition. To meet this challenge, we looked for the concept of “oral comfort” when eating a food. The present study aimed at i) exploring the concept of oral comfort when eating according to elderly people in order to develop a questionnaire to evaluate the oral comfort when eating a food and ii) asking elderly people to evaluate various meat and cereal products using this questionnaire. Results of focus groups highlighted that oral comfort when eating a food is a multi-dimensional concept which includes dimensions related to food oral processing (ability to form and swallow food bolus), food sensory properties (texture and taste) and to a lesser extent pain sensations. Furthermore, the oral comfort questionnaire developed in the present study enabled a discrimination of products and highlighted the fact that some products supposed to fit with elderly people capacities and needs were not rated as the most comfortable foods by the elderly people. The concept of oral comfort when eating a food should be taken into account by those who are willing to design food products tailored to the elderly population. The questionnaire could be an interesting tool to assess oral comfort when eating a food in the elderly population.

National audience; Introduction et but de l'étude : Le vieillissement peut s'accompagner de changements dans la sphère orale tels que la diminution de l'efficacité masticatoire ou encore la dégradation quantitative et qualitative de la salive. Ces changements, peuvent avoir un impact sur la capacité des personnes âgées à dégrader l'aliment, conduisant éventuellement à des comportements d'évitement. Matériel et méthodes : 62 séniors (>65 ans) vivant à domicile et ne présentant pas de pathologie chronique ont été recrutés sur la base de leur nombre d'unités fonctionnelles postérieures, c'est à dire du nombre de paires de dents antagoniste postérieure ayant au moins une zone de contact pendant la mastication. Deux groupes de sujets, 30 (15H ; 15F) présentant une bonne dentition (âge= 72 ± 5 ans, nombre d'unités fonctionnelles = 8 ± 1) et 32 (15H ; 17F) présentant une mauvaise dentition (âge= 72 ± 5 ans, nombre d'unités fonctionnelles = 3 ± 1) ont été sélectionnés. Des données de flux salivaires au repos et stimulé et d'auto-évaluation de la xérostomie ont également été relevées. Chaque participant a complété un relevé alimentaire de 5 jours, ce qui a permis de déterminer la fréquence de consommation, les quantités consommées ainsi que les apports en nutriments. Les analyses statistiques ont été faites par ANOVA à un facteur et régressions linéaires. Le protocole a été approuvé par le CPP Est-1 N° IRB 2016-A00916-45. Résultats et Analyse statistique : Les personnes en mauvaise dentition consomment des fruits et légumes moins fréquemment que ceux en bonne dentition (Bonne dentition : 5.1 ± 0.3 occasions de consommation par jour, Mauvaise dentition : 4.1 ± 0.3 occasions de consommation par jour, F(60)=4.9, p

Fat perception during eating is a complex sensation that involves various sensory modalities, such as texture, aroma and taste. Taste is supported by the discovery of fatty acid receptors in the tongue papillae. Dietary fat is mainly composed of esterified fatty acids, whereas only free fatty acids can bind to taste receptors. Some authors have mentioned the necessity and efficiency of salivary lipolytic activity to hydrolyse the esterified fatty acids present in foods and enable fat perception. Our hypothesis is that salivary lipolytic activity is also involved in regulating the basal level of salivary fatty acids in humans. To test this hypothesis, total fatty acid (TFA) and free fatty acid (FFA) concentrations and selected salivary characteristics (such as lipolytic activity) were analysed in the resting saliva of 54 subjects. The results show differences in the TFA and FFA profiles, with TFA and FFA concentrations of 8.99 and 3.56 µg/mL of saliva, respectively. Interestingly, lipolytic activity had a significant positive correlation with FFA concentration (0.51, p

International audience; The aim of this work was to examine the influence of aroma and tasting temperature, on the detection of and difference sensitivity for fat content in cottage cheese. The detection (DetT) and difference (DiffF) thresholds were determined in 4 different conditions defined by a combination of two factors, each involving two variables: a nose clip (with or without) and the tasting temperature (7 C or 15 C). Forty non-trained panelists participated in this study. Thresholds were determined using two-alternative forced-choice (2-AFC) tests in ascending concentration series. Individual thresholds were calculated using the Best Estimate Threshold (BET) method.An increase in tasting temperature induced a decrease in the DetT and Difff, while the use of a nose clip led to an increase in both thresholds. A hierarchical cluster analysis evidenced three homogeneous subsets of subjects with contrasting sensitivity profiles: subsets 1 (n = 7) and 2 (n = 9) were characterized by high and low DetT and Diffr values, respectively, for all conditions, while a larger third subset (n = 24) included subjects with medium thresholds values that varied from one condition to another. Unlike the other subsets, subset 3 was significantly influenced by the change in tasting temperature, whereas only subset 1 showed no sensitivity improvement when aromas were perceptible.

This advance article is part of themed collection: Structure & Sensory.; International audience; The aim of the present paper was to determine, from four model cheeses differing in fat content and firmness and consumed by fourteen well characterised subjects, the respective impacts of in vivo aroma release, bolus rheology, chewing activity, mouth coating and salivary composition on dynamic aroma perception. The originality of the approach is that it considers all the parameters together and is able to evaluate their relative contribution using multi-block partial least square (MB-PLS) regression. The fruity aroma perception of the more hydrophilic compound (ethyl propanoate) was related to its dynamic release parameters before swallowing whereas the blue cheese aroma perception of the more hydrophobic compound (nonan-2-one) was related to its dynamic release parameters after swallowing and was highly impacted by mouth coating. Moreover the MB-PLS approach made it possible to evidence the combined effects of saliva composition and cross-modal interactions to understand why in some cases dynamic aroma perception could not be explained by dynamic in vivo aroma release data. Subjects with a low sodium content in saliva perceived fruity aroma which is not congruent with saltiness as less intense and salt-congruent (blue cheese) aroma as more intense, which was explained by their higher sensitivity to salt. Subjects with high lipolysis activity perceived fruity aroma which is not congruent to fat as less intense and fat-congruent (blue cheese) aroma as more intense, which should be explained by the link between lipolysis activity and fat sensitivity. These results could be considered for the reformulation of foods towards specific populations taking into account nutritional recommendations.

Food choice is defined as providing the opportunity for an individual to select the food he or she wants to consume while food variety is defined as providing an individual with foods that differ on at least one sensory characteristic. Literature shows that providing food choice or providing food variety may increase meal enjoyment and food intake. However, these two factors have been mainly investigated separately, while they may actually co-occur in real-life settings. In fact, in many out-of-home catering situations, individuals have the possibility to choose as many dishes as they desire from among different proposals for their meal. The aim of the present study was to assess the impact of choice and/or variety on food liking and food intake during a lunch. Fifty-nine no rmal-weight adults were recruited under the condition that they equally liked three vegetable dishes (green beans with butter, zucchinis with olive oil, spinach with cream). Volunteers participated in four sessions at lunch time (i) participants were served with one dish randomly selected from among three alternatives (no-choice/no-variety condition); (ii) participants chose one dish from among three alternatives (choice/no-variety condition); (iii) participants were served with the three dishes (no-choice/variety condition); and (iv) participants chose as many dishes as they desired from among three alternatives (choice/variety condition). Outcomes included vegetable intake (plates were weighted before and after consumption) and vegetable liking (participants rated their liking on a 10-point hedonic scale). Results showed that providing choice increased vegetable liking and vegetable intake, while offering a variety of vegetables only increased their liking. No synergy effe ct between choice and variety was observed on vegetable liking and vegetable intake (i.e. the effect in the choice/variety condition was not significantly higher than the effects in no-choice/variety and the choice/no-variety conditions).

The cumulative effects of physiological aging, diseases and drugs often impair food oral processing (mastication, salivation and swallowing), which is the most important point where foods organoleptic properties can be perceived and elicit sensory pleasure. The aim of the present study was to explore the concept of “oral comfort” when eating a food in the elderly. Firstly, three focus groups were conducted with elderly people to develop concepts linked to oral comfort when eating. Results of the focus groups, which included brainstorming (What is oral comfort for you?) and food tasting, led to the following definition: “A comfortable food is easy to chew, to humidify with saliva and to swallow. Eating it does not cause face or mouth pain. The food is neither too fat nor dry but has a firm texture, is not too hard and is rather melty. Its taste is well dosed out, not too tasteless or too strong.” Secondly, a questionnaire was designed from verbatims collected during the focus groups, including items on oral comfort and pain, on easiness to chew, to moisten and to swallow as well as on texture and flavor properties. Then, around 40 participants over 65 years old, with or without chewing and/or salivary difficulties, completed this questionnaire for various food textures within three categories (dairy, meat and bread products). Results showed that the questionnaire allows discriminating food matrices. For instance, plain beef steak was perceived as less comfortable than ground steak, easier to chew. However, plain and ground steaks were perceived as less comfortable than beef cheek which was easier to moisten. The faith is to use the questionnaire for developing products which will meet the oral capacities of elderly people while preserving eating pleasure, a major challenge within the context of an aging population.

Oral health changes with ageing and sometimes, eating food can be a real challenge. One of the solutions could be to give food with modified texture: pureed ground or even reconstituted meat. This solution is not necessarily adapted to all oral health problems encountered by the elderly, and food could be perceived as uncomfortable.The aim of the present study was to understand why some foods are considered as comfortable and some others are not, and if the judgment of comfortability is linked to oral health.39 elderly people, half with a good oral health - no missing teeth except third molar, at least 7 posterior dental occlusions and no denture - and half with a poor oral health - less than 5 posterior dental occlusions - were recruited. These subjects tasted six meat products differing by their origin and texture: a ground and a plain beef, beef cheek, chicken aiguillette, reconstituted chicken aiguillette and chicken balls. For each product, the elderly subjects had to complete a new questionnaire designed to evaluate food comfortability through the following dimensions: the easiness to eat the peice of meat, the action needed to masticate and swallow, the potential pain felt during tasting, and the intensity and the embarrassment of texture and flavor descriptors.The results showed that the developed questionnaire allows discriminating food matrices and showing that comfortability of food consumption can be defined by texture, potential pain felt during tasting, or even the action needed to masticate and swallow. The influence of oral health on food comfortability will be discussed.

The aim of this work was to clarify the influence of the properties (firmness and fat content) of a solid processed model cheese on in vivo aroma release while considering the role of the in-mouth process during both mastication and post-swallowing steps, and the hydrophobicity of aroma compounds, on a large number of well characterized subjects. In vivo aroma release was studied on 44 subjects who freely consumed six processed model cheeses flavoured with the same concentration of nonan-2-one and ethyl propanoate. Globally, an increase in firmness induced an increase in chewing duration, amount of saliva incorporated into the food bolus, total amount of aroma released and rate of release. The kinetics of release clearly differed between the two aroma compounds. Ethyl propanoate presented a higher release rate for firmer cheese and was more released during the mastication step, whereas nonan-2-one was more released during the post-swallowing step and more persistent in the mouth, due to its higher hydrophobicity. Consuming cheeses with a higher fat content led to a higher amount of product remaining in the mouth after swallowing, a lower amount of nonan-2-one released and a longer persistence of nonan-2-one in the breath. The results could be helpful to better understand the relative influence of the parameters related to products and subjects in order to reformulate foods with good sensory acceptability. Copyright (C) 2012 John Wiley & Sons, Ltd.

The chewing process transforms food into bolus for a safe swallow. It is known that humans adapt their chewing behavior to food product characteristics. This study aimed at identifying individual chewing strategies of healthy consumers and determining the respective consequences on bolus properties. For that purpose, the chewing activity of 50 subjects was recorded during consumption of five model cheeses. Boluses were collected at the swallowing threshold for rheological analyses. We found that 30% of subjects showed only slight adaptation of chewing activity to product characteristics and thus produced boluses with different rheological properties. Among the 70% of subjects who adapted their chewing behavior, 57% adapted their behavior via chewing time and 40% adapted their behavior via chewing time and muscular contraction amplitude. Among the bolus rheological parameters, only consistency was not influenced by chewing strategies. Hence, it seemed to be a determinant factor of the swallowing threshold for these products. PRACTICAL APPLICATIONS Flavor compounds are released during the oral processing of food. It is thus important to understand how consumers form a bolus and to analyze the consequences of chewing behaviors on bolus properties at the swallowing threshold, at the end of the oral stage of food, to clarify the role of mastication in the release of stimuli responsible for perception. Chewing strategies and bolus properties are some of the key factors of flavor release and product acceptability that is of interest for food manufacturers who can use these factors as additional parameters for new solid product design.

On the one hand, a choice situation gives an individual a sense of freedom, autonomy and control over the environment, which triggers higher intrinsic motivation and higher satisfaction (Deci and Ryan, 1985). Indeed, it has been demonstrated that a choice situation elicits higher food intake in a meal context (Rohlfs Domínguez et al., 2013; Parizel et al., 2015). On the other hand, providing variety has been demonstrated to enhance food intake. Rolls et al. (1981) argued that providing variety during a meal prevents the onset of specific sensory satiation which refers to the declining satisfaction generated by the monotonous consumption of a certain food. However, in an out-of-home catering situation, it frequently occurs that people face both a “choice” and “variety” situation. People can often select their menu among several proposals and are also allowed to combine several alternatives for the same dish (e.g., selecting two side dishes for the main course).The present experiment aims at comparing the impact of choice and/or variety on food intake. Sixty normal weight participants were recruited under the condition that they equally liked three recipes of vegetables (green beans with butter, zucchinis with olive oil, spinach with cream). Volunteers participated in four sessions at lunch time. In the no choice/no variety condition, volunteers were randomly assigned one vegetable recipe. In the no choice/variety condition, volunteers were served with the three vegetable recipes. In the choice/no variety condition, volunteers were asked to choose only one vegetable recipe among the three presented. In the choice/variety condition, volunteers were free to choose as many vegetable recipes as they wanted. For all conditions, participants were allowed to eat as much as they desired.Results still under analysis allowed to decipher the impact of choice versus variety and to reveal synergy between these two factors on food intake.

This chapter proposed an integrated approach to better understand the role of cheese composition, physiological parameters, and individual chewing behavior on aroma release and perception. Product effect (six cheeses) was more important than subject effect (14 healthy consumers). Differences were observed according to the hydrophobic properties of aroma compounds. More ethyl propanoate and less nonan-2-one (more hydrophobic compound) were released from cheeses with higher fat levels, and more of these two aroma compounds were released from firmer cheeses compared to softer cheeses. For nonan-2-one, the amount of aroma released could not explain the perception due to fat-aroma sensory interactions.

International audience; The decrease in medium permittivity due to temperature rise could play an important role in the denaturation/polymerization ofheat-treated b-lactoglobulin. The permittivity of a b-lactoglobulin suspension was decreased, either by heat treatment or by addingorganic solvent, and the rate of loss of the native b-lactoglobulin was estimated by SDS-PAGE analysis. Setting the permittivity to63.8 by addition of organic solvent, induced b-lactoglobulin polymerization, but it differed from that induced by change in permittivity upon thermal treatment itself (heating to 70 C). To explain the protein polymerization process induced by heating, other physical parameters should be taken into account, such as change in water organization around the protein.

The aim of our study was to explain inter-individual differences on in vivo aroma release during cheese consumption by oral physiological parameters. To reach this objective, 34 subjects were recruited. Their salivary flow, oral volume and velum opening were determined. Six cheddar-based melted cheeses with different fat levels and firmness were flavoured with nonan-2-one.(NO) and ethyl propanoate (EP). During their consumption (free protocol), in vivo retro nasal aroma release was followed by Atmospheric Pressure Chemical lonisation-Mass Spectrometry (APCI-MS). Chewing activity was evaluated by electromyography recordings. Bolus saliva content, mouth-coating, and bolus rheology were also determined. Based on the quantity of aroma released before and after swallowing, subjects can be clustered into three groups: the first one (HRG) is characterized by a large quantity of aroma release whatever the aroma compound; the second one (MRG) showed a large release for EP and a lower one for NO; the third group (LRG) was characterized by a low quantity of aroma release whatever the compound. Whatever the group of subjects, fat and firmness effects differed according to the aroma compound. EP release increased with firmness and fat content, whereas NO release was not affected by firmness and decreased when fat content increased. Physiological parameters which better differentiated the three groups of subjects according to their release behaviour were chewing activity, mouth coating and frequency of velum opening. Subjects from HRG were differentiated from LRG subjects by a higher chewing activity, and more frequent velum opening. Subjects from MRG presented a lower mouth coating explaining their lower release of NO, the more hydrophobic compound. This study shows that the total amount of aroma released in the nasal cavity during food consumption depends not only on the characteristics of the product but also on the oral physiology of the subjects and on their food oral processing.

For human beings, the mouth is the first organ to perceive food and the different signalling events associated to food breakdown. These events are very complex and as such, their description necessitates combining different data sets. This study proposed an integrated approach to understand the relative contribution of main food oral processing events involved in aroma release during cheese consumption. In vivo aroma release was monitored on forty eight subjects who were asked to eat four different model cheeses varying in fat content and firmness and flavoured with ethyl propanoate and nonan-2-one. A multiblock partial least square regression was performed to explain aroma release from the different physiological data sets ( masticatory behaviour, bolus rheology, saliva composition and flux, mouth coating and bolus moistening). This statistical approach was relevant to point out that aroma release was mostly explained by masticatory behaviour whatever the cheese and the aroma, with a specific influence of mean amplitude on aroma release after swallowing. Aroma release from the firmer cheeses was explained mainly by bolus rheology. The persistence of hydrophobic compounds in the breath was mainly explained by bolus spreadability, in close relation with bolus moistening. Resting saliva poorly contributed to the analysis whereas the composition of stimulated saliva was negatively correlated with aroma release and mostly for soft cheeses, when significant.

Inter-individual variations of in vivo aroma release kinetics have been observed widely in the literature. However, the corresponding causes are yet to be clearly identified. For this purpose, 68 subjects in whom salivary flow rates (at rest and Parafilm™-stimulated) had been determined were recruited for the study. The release of menthone was measured using atmospheric pressure ionisation–mass spectrometry during the consumption of a sweet mint tablet. The subjects complied with an imposed protocol of oral movements. Inter-individual variability was investigated through a qualitative analysis of the oral movements inducing menthone release, and through quantitative analysis. Swallowing events were the main contributors to menthone release. Tongue and jaw movements did not induce menthone release in all the subjects, thus explaining inter-individual differences in menthone release curve profiles. Inter-individual differences in term of the quantity of menthone released partly arose from the percentage of sweet mint tablet degradation. The greater the degree of degradation, the more menthone was released. Although protein concentrations in the saliva gave a first indication of differences in mint tablet degradation between subjects, other factors such as the content of specific proteins, and particularly enzymes, still need to be explored. Copyright © 2011 John Wiley & Sons, Ltd.

International audience; We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04) that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H) and low (L). The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition.

International audience; Mouth coating, defined as the residual food that sticks to the oral surface after food ingestion, plays an important role in both the delivery of food components and mouth feel and after-feel perceptions. The aim of this work was to adapt a rapid and simple instrumental method to the quantification of food remaining after the in vivo ingestion of a solid food. This method was investigated in 12 non-trained subjects who consumed four melted cheeses differing in terms of their fat and water contents. Mouth coating was determined by fluorescence measurements using curcumin, an oil-soluble dye that had been added to the cheeses during their preparation. The results obtained showed that this method was reproducible, reliable and discriminating and could be used for solid cheeses covering a broad range of textures.

Aroma perception is a determinant factor in food choices and acceptability by consumers. To be perceived, aroma compounds must be released in the mouth during food breakdown, transferred into the nasal cavity to reach the olfactory receptor and then be perceived. So, in order to control aroma perception, knowledge of the main factors that can influence in-mouth aroma release is of major importance. Focusing on dairy products, this review article investigates the factors due to: (i) food products, and mainly the influence of food composition and structure on aroma retention and release; (ii) the inter-individual variability of subjects, mainly chewing behaviour, saliva rate and composition and their influence on aroma release; and (iii) the interactions between food products and subjects and their impact on aroma release and perception. We also discuss the various instrumental and sensory methodologies that are often used to study aroma-texture interactions in dairy products, with particular focus on articles that compare in vivo aroma release and perception in dairy products. This review emphasizes that the relationship existing between in vivo aroma release and perception in dairy products is strongly dependent on the type of texture relative to two mechanisms; physicochemical mechanisms based on the modification of aroma release and a cognitive mechanism based on aroma-taste-texture interactions. These two mechanisms exist simultaneously but have more or less impact on aroma perception, depending on the type of texture.

Review; International audience; During eating, foods are submitted to two main oral processeschewing, including biting and crushing with teeth, and progressive impregnation by saliva resulting in the formation of a cohesive bolus and swallowing of the bolus. Texture influences the chewing behavior, including mastication and salivation, and in turn, these parameters influence texture perception and bolus formation. During this complex mouth process, flavor compounds are progressively released from the food matrix. This phenomenon is mainly dependent on the food texture, the composition and in-mouth breakdown, and on saliva impregnation and activity, but an individual's anatomical and physiological aspects characteristics should also be taken into account. This article reviews the knowledge and progresses on in-mouth processes leading to food breakdown and flavor release and affecting perception. Relationships between food texture and composition, food breakdown, oral physiology, and flavor release are developed and discussed. This review includes not only the mechanical aspects of oral physiology but also the biological aspects such as the influence of saliva composition, activity, and regulation on flavor perception. In vitro and in silico approaches are also described.

International audience; This study aimed to characterise a non-conventional protein source: a powder made from earthworms, and to evaluate its potential use as human food. The way it was prepared led to low solubility and wide particle size distribution. Sensory analysis was used to assess the acceptability and the organoleptic properties of maize-based pan-cakes fortified with this novel protein powder. Satisfying products were obtained with a substitution level of 5.5% (w/w) earthworm powder in pan-cakes. GC-MS allowed the identification of more than seventy volatile compounds that may be responsible for the off-odour of the powder. The most abundant chemical groups found in the volatile fraction were ketones with undecan-2-one, alcohols with pentan-1-ol, and aldehydes with hexanal. Partial delipidation was tested as a way to improve the organoleptic quality of the powder. It clearly led to less intensely coloured samples but delipidation must be optimised to have an impact on odour.

International audience; The influence of the texture on perceived aroma intensity and on in-vivo and in-vitro aroma release was investigated on three types of dairy products, prepared with different textures. Aroma release depends on in mouth breakdown of the product. The consequences of a textural modification on aroma perception were not the same for the different products. In the case of liquid to semi-liquid products (yogurt and custard dessert), in-vivo aroma release decreased when viscosity increased. For firm gels (model cheeses) in-vivo aroma release was found to increase when cheese hardness increased, but inverse results were obtained in in-vitro conditions. Thus, aroma release could explain perceived aroma intensity for yogurts but not for cheeses for which large inter-individual differences were observed. An adaptation of the chewing pattern was supposed in-vivo leading to high structural modifications.

International audience; The effect of textural modifications of solid milk gels on in vivo aroma release and aroma perceptionwas investigated with a panel of 14 subjects. Great inter-individual differences were observed onaroma-release data, and the consequences of these differences on aroma perception were studied.From a hierarchical cluster analysis performed with several parameters extracted from release curves,the subjects were gathered into two groups, and a specific aroma-release profile was identified foreach one. Then, by using a sensory profile, we showed that the intensity of the aroma perceptionwas dependent on the release profile presented by the panelist. Second, we observed that, duringthe chewing phase, the aroma was perceived as more intense for the firmer gel and for panelists forwhom the aroma release begins during the chewing of the product.

International audience; Using atmospheric pressure chemical ionization-mass spectrometry, aroma release was investigatedin vivo and in vitro from three cheese-like gels with different hardnesses. In vivo, nosespaceexperiments were performed with 14 subjects. Results showed that the harder gel induced a greaterand a faster release of all aroma compounds. In vitro, aroma release was followed in a mouth simulatorwhere breakdown was mechanically produced. The same rate of stirring was applied to the threegels. In these conditions, we found that the amount of aroma released from the three gels was notdiscriminant. Thus, modification of gel structure had a strong impact on in vivo aroma release, butstructural variations alone were not sufficient to induce a greater release. Natural breakdown providedby panelists during food consumption and adapted to the texture of the food was proposed to be thekey parameter affecting in vivo aroma release.

International audience; Three mixed milk gels with different structures were formulated. The addition of increasingconcentration of chymosin resulted in an increase in gel hardness evaluated by penetrometrymeasurements. The in vivo release of aroma compounds from these gels was studied byAtmospheric Pressure Chemical Ionisation - Mass Spectrometry (APCI-MS) in Nosespaceconfiguration and with a panel of fourteen subjects. Aroma release was found to be stronglyaffected by structure variation. An increase in gel hardness resulted in an increase in theamount and the rate of aroma release. In parallel, sensory analysis was performed using theprofile method. Data treatment revealed that the different structures were perceived at thesensory level and could be described with numerous texture attributes. Intensity of saltperception was found to decrease from the softer to the harder gel. Overall aroma perceptionpresented a tendency to decrease with gel hardness. Aroma perception could not be correlatedwith aroma release parameters, and cross-modal interactions were not excluded to explainresults.

We hypothesized that food texture modifications might alter anticipatory reflexes, feeding behavior, and the postabsorptive consequences of ingestion. Two sets of complete meals with different textures but the same macronutrient composition were prepared. The first set was either a soup containing chunks of food (mixture) or the same soup blended until smooth (purée). The second set was either a rusk (R), a sandwich loaf (SL), or a liquid rusk meal (LR). We measured hunger and fullness feelings after ingestion of each food in a calibrated lunch, the ingestion rate, the duration between lunch and a spontaneous dinner request, the energy value, and the macronutrient composition of the ad libitum dinner. We also studied plasma modifications and respiratory gas exchanges from lunch to dinner. Feelings of hunger and fullness were not affected by texture modifications. The purée soup was consumed faster than the mixture ( P < 0.05), and insulin, triacylglycerol, and energy expenditure were greater with the purée ( P < 0.05). LR was less palatable than the other rusk lunch versions ( P < 0.001), and R was ingested more slowly ( P < 0.05). The lowest increase in plasma glucose occurred with SL, and the highest energy expenditure was seen with LR ( P < 0.05). In humans, food texture modification affects not only eating patterns and palatability of ingestants but also metabolic management.

A complete diet was prepared with cooked pieces of meat, beans, cream starch, and water and presented to the rats in two different textures: a blended purée and a rough mixture that required a lot of chewing. We hypothesized that this texture modification might change both anticipatory reflexes and feeding behavior. Feeding rate, meal size, intermeal intervals, and their correlation were monitored in response to each texture. The long-term (6 wk) effect on body weight was assessed. Periprandial plasma glucose, insulin, glucagon, and lipid concentrations were assayed. Whole and background metabolism, respiratory quotient, and locomotion were measured using a computerized calorimeter of original design. In the short term, rats preferred the mixture. However, after 3 wk, they ingested more purée than mixture and gained more body weight per gram of food ingested as purée. Insulin response declined earlier with the mixture. During meals, glycerol and free fatty acid increased earlier with purée, whereas in the postprandial period, glycerol increased earlier with mixture. The metabolic rate, however, was not significantly affected. We concluded that texture, an everyday manipulation performed on food for human consumption, affects not only palatability of ingestants but also their metabolic management in the short and long term.

International audience; no abstract