Search

International audience; AIMS: GLP-1 analogues decrease food intake and have great promise for the fight against obesity. Little is known about their effects on food hedonic sensations and taste perception in poor controlled patients with type 2 diabetes (T2D). MATERIALS AND METHODS: Eighteen T2D patients with BMI >/=25kg/m(2) and poor controlled glycemia were studied before and after 3 months of treatment with Liraglutide. Detection thresholds for salty, sweet and bitter tastes, optimal preferences, olfactory liking, wanting and recalled liking for several food items were assessed. Subjects also answered questionnaires to measure their attitudes to food. RESULTS: T2D patients had a significant decrease in bodyweight and HbA1c after treatment with Liraglutide. Liraglutide improved gustative detection threshold of sweet flavors, and decreased wanting for sweet foods and recalled liking for fatty foods. It also led to a decrease in feelings of hunger. CONCLUSIONS: Liraglutide increases sensitivity to sweet tastes and decreases pleasure responses for fatty foods in poor controlled T2D patients, and is of particular interest in the understanding of the mechanisms of weight loss. CLINICAL TRIAL: NCT02674893.

International audience; BACKGROUND: Although sensory description of wines in scientific literature is very large, there is an evident lack of studies describing wines from a dynamic approach. The objective of this study was to describe the evolution of the sensations perceived in red wines from Rioja Alavesa by using Temporal Dominance of Sensations (TDS) and also to compare wines made with the two winemaking procedures used in Rioja Alavesa: carbonic maceration (CM) and destemming (DS). RESULTS: Ten sensory attributes were evaluated in eight wines (four CM and four DS wines) in triplicate by a panel of 16 trained assessors. Red/black berry and woody aromas were dominant firstly, whereas heat, astringent, bitter and pungent sensations were dominant later. CM wines showed higher dominance for woody, spicy, pungent and acid sensations and lower dominance for red/black berry aroma and astringency than DS wines. CONCLUSION: This study is the first to describe Rioja wines from a dynamic approach and it also provides information about the dynamic sensory differences between wines made by CM or by DS. In this sense, this work shows the usefulness of TDS to describe and differentiate wines and to provide additional information to the conventional static descriptive analysis. (C) 2015 Society of Chemical Industry

Editeur : Future Medicine ; ISSN: 2044-9038 ; ESSN: 2044-9046; Roux-en-Y gastric bypass is one of the most effective treatments for morbid obesity as it results in long-term weight loss and significant remission of obesity-related comorbidities. Although it is successful in causing weight loss, the underlying mechanisms are not completely understood. A significant decrease in calorie intake related to a shift in food preferences towards lower-calorie-dense foods has been observed after the surgery. This modification in ingestive behavior occurs through changes in the sensory and reward domain of taste. Potential mediators of these taste modifications are the exaggerated levels of gut hormones or altered gut nutrient sensing. Understanding the molecular mechanisms involved in the Roux-en-Y gastric bypass-induced taste/food preference modifications would be crucialfor the development of 'knifeless' treatments. Obesity is a leading cause of death [101]. The comorbidities of obesity include cardiovascular disease, Type 2 diabetes mellitus, cancer, nonalcoholic fatty liver disease, arthritis and infertility, among others [1-6]. Roux-en-Y gastric bypass (RYGB) is one of the most effective treatments for morbid obesity [7], resulting in long-term weight loss maintenance, significant remission of obesity-related comorbidities [8-10] and decreased overall mortality [10]. RYGB results in five main anatomical changes: Reduction of the stomachize (15-30 ml), leaving a large stoma to allow food rapid passage between the esophagus and midgut; Food bypassing the stomach and the first part of the proximal small bowel; Altered bile flow through the same proximal small bowel; Anastomosis of the midgut to the stomach, allowing earlier contact of food with the distal small bowel; Disruption of vagal fibers across the stomach, while leaving the main branches of the vagus intact. Although the RYGB procedure is successful in causing weight loss, the relevant mechanisms are not completely understood. Even though the procedure was originally designed to cause restriction, the flow of food is accelerated from the esophagus to the midgut through the large gastro-jejunostomy [11]. Calorie malabsorption does not play a physiologically significant role as fecal fat and calorie loss is minimal, while many patients actually report constipation after RYGB [11,12]. Significant increase in energy expenditure have been reported after RYGB in animals [6,13-15] and in one study in humans [16] but this change may be triggered by changes in body composition. However, one study has shown that diet-induced thermogenesis of multiple meals results in an overall increase in 24-h energy expenditure compared with a group of patients that lost the same amount of weight with a vertical-banded gastroplasty [16]. Significant decrease in calorie intake has also been reported after the surgery in humans [17,18]. The decrease in total calorie intake is related to reductions in hunger, increases in satiety, changes in meal patterns, in addition to a shift in food preferences towards lower-calorie-dense foods [18-22]. Here, we review the changes in eating behavior after RYGB, and focus on potential mechanisms underlying this shift, including changes in quantitative taste identification and taste ingestive motivation (reward). Finally, we explore potential mediators underlying this mechanism, such as gut hormones or nutrient sensing.

Article de vulgarisation; National audience; The sense of taste involves multimodal sensory activation to detect and identify many flavors. Today, five primary tastes have been identified (sweet, salt, sour, bitter and umami). These are often combined to form complex tastes. The physiology of gustatory pathways is complex. The activation of gustatory receptors located in the mouth leads to an ascendant pathway through the neurons of the solitary nucleus in the brainstem and the neurons located in the thalamus. After the thalamus, the gustative signal modulates the ipsilateral primary taste cortex and then the secondary taste area. The secondary taste cortex, which combines representations of taste and smell, allows cortical processing and the convergence of the different sensory pathways. The other sensory modalities, such as somatosensory, olfactory, visual and hearing modalities, also interact with gustation at different stages of gustative integration. The sense of taste has three main roles: to detect and identify foods that can be eaten, to provide information in the decision to ingest or reject the food, and to trigger the digestion, absorption and storage of food. Taste problems are frequent and not diagnosed often enough. If physicians do not take them into account, they can worsen the underlying disease by causing malnutrition. Many drugs and diseases can cause gustatory loss. The underlying mechanisms are various and often unknown. Increasing our knowledge of taste physiology could improve our understanding of taste pathology. The main aim is to treat taste problems in order to avoid malnutrition and aggravation of the underlying disease.; Parmi les cinq sens, le goût correspond à une activation sensorielle multimodale permettant de détecter et d’identifier de nombreux stimuli que sont les saveurs. Il existe actuellement cinq saveurs primaires (sucré, salé, acide, amer, umami) qui peuvent se combiner entre elles pour former des sensations gustatives plus élaborées. La physiologie de la gustation est complexe. Les substances sapides contenues dans les aliments activent les récepteurs gustatifs situés dans les bourgeons du goût. Les cellules gustatives ainsi stimulées transmettent le signal au cortex gustatif primaire ipsilatéral. Les aires corticales secondaires, communes aux sensations olfactives et gustatives, permettent ensuite l’intégration des informations sensorielles. Les autres sensibilités (la somesthésie avec la sensibilité trigéminale, l’olfaction, la vision et l’audition) interagissent avec la gustation. Trois rôles principaux sont attribués au goût : la détection et l’identification des aliments, le rejet ou l’acceptation de l’aliment grâce à la composante hédonique des sensations et enfin, la préparation de la digestion, de l’absorption et du stockage des nutriments. En pathologie, les altérations du goût sont fréquentes, bien que sous-diagnostiquées, et peuvent aggraver la maladie sous-jacente en induisant une dénutrition. Des anomalies du goût peuvent être induites par de nombreuses pathologies ou des médicaments. Les mécanismes responsables varient en fonction de la pathologie et sont souvent mal connus. L’amélioration des connaissances des mécanismes physiologiques qui sous-tendent la gustation permettra de mieux comprendre les altérations du « goût » en pathologie pour tenter d’y faire face chez les patients à risque de dénutrition.

International audience; The discovery of leptin by Friedman and coll. in 1995 was a major step forward in our comprehensive view of energy homeostasis. Since the original paper, a tremendous amount of work has been performed in laboratories all over the world. Many recent reviews have described this work in details. In the present review, we focus on the role of leptin on food intake. It is accepted by most authors working in this field that the control of food intake can be divided in two closely-related system: the homeostatic system and the hedonic system. Leptin has been shown to act on both systems.

Sensory-specific satiety (SSS) is defined as a decrease in the pleasantness of a specific food that has just been eaten to satiation, while other non-eaten foods remain pleasant. The objectives of this study were the following: (1) to investigate whether SSS for a food is affected by the ad libitum intake of other foods presented sequentially during a meal, (2) to compare the development of SSS when foods are presented simultaneously or sequentially during a meal, and (3) to examine whether SSS is modified when foods are presented in an unusual order within a meal. Twelve participants participated in three tasting sessions. In session A, SSS for protein-, fat- and carbohydrate-rich sandwiches was measured after the ad libitum consumption of single type of each of these foods. In session B, SSS was measured for the same three foods consumed ad libitum but presented simultaneously. Session C was identical to session A, except that the presentation order of the three foods was reversed. The results indicate that once SSS for a given food is reached, the ad libitum consumption of other foods with different sensory characteristics does not decrease SSS, regardless of the order in which the foods are presented. Once reached, SSS is thus not subject to dishabituation during a meal. (C) 2012 Elsevier Ltd. All rights reserved.

In this study, effect of partial alcohol reduction on the sensory modification of red wines was investigated. A Merlot and a Syrah wine were partially dealcoholized using reverse osmosis technique to span a range of three different alcohol contents (14–10%) by grape variety. Preliminary triangle tests indicated the existence of very slight differences between the dealcoholized wines of the study. Therefore, adapted descriptive methodologies had to be used. In a first step, wines were described with a comparative sensory profile by 16 trained panellists on 15 sensory attributes. Then, the same panellists profiled the wines with the TDS technique, which consists in identifying and rating sensations perceived as dominant repeatedly until the perception ends. Analysis of variance of the classical descriptive data confirmed the existence of subtle sensory differences among wines from a given grape variety with only three and five discriminated attributes for Merlot and Syrah, respectively. Analysis of TDS curves emphasized twice more discriminated attributes and pointed up temporal differences between wines that did not appear with the conventional sensory profile. Used together these methods appeared as promising as they resulted in complementary and complete descriptions of wines. Effect of dealcoholization was variable from one grape variety to another one. The constant effects of alcohol reduction, common to both Merlot and Syrah were the perception decrease of heat sensation, the substitution of heat sensation in attack by astringent (Merlot) or red fruits (Syrah) sensations, the decrease of bitter sensation after attack to the expense of fruity sensations, and the decrease of length in mouth. In case of Merlot, texture and astringency sensations were also affected by alcohol reduction whereas for Syrah, sweet sensation was affected. Wine is a complex product lying on a fragile balance and the least parameter modification induces variable effects according to the type of wines. Several kinds of interactions between ethanol and wine component must take place and make difficult the generalization of alcohol reduction effect on the sensory perception of wines.