<div> <div> <div> <p>Saliva influences chemical and textural sensations, yet details on sources of individual variability for these phenomena are still lacking. In this project, we investigated fatty sensations, dietary habits, and saliva’s emulsifying properties. Through a remote tasting and spitting protocol, participants were asked to rate sensory properties of fatty candies with varying concentrations of added linoleic acid (LA) as well as discriminate among fatty candies with/without LA and high/low fat ranch dressings. Additionally, participants swished and expectorated an oil/water mixture, and the expectorated emulsion was visually analyzed. Dietary habits were also assessed by 3-day dietary recalls. </p> <p>Linear mixed model was used to analyze sensory response, diet, and spit data. Sensory ratings of fatty candies indicate differences based on successful completion of either discrimination tasks. People who passed either discrimination tests (N=26 passed LA; N=22 passed high/low fat tests) rated higher “Fattiness” for the highest LA concentration. In contrast, people who failed the tests (N=36 failed LA; N=40 failed high/low fat tests) rated higher “Bitterness” with the highest LA concentration. Importantly, only 7 individuals overlapped in these two groups who passed the discrimination tasks. Lower total fat intake and larger expectorated fat layer were associated with higher “Bitterness,” particularly among those who passed the LA discrimination test and those who failed the high/low fat test. Moreover, lower protein and greater carbohydrate intake seemed to associate with the greater formation and stability of oral emulsions, particularly in individuals who failed the high/low fat discrimination task. Other factors such as total fat intake, medication usage, and BMI were mixed. In conclusion, sensory experience of fatty candies may vary based on the ability of an individual to sense the LA or fat content, and saliva’s ability to emulsify fat into water may vary with diet. </p> </div> </div> </div>

Plusieurs fabricants de biscuits et gâteaux français se sont engagés à mettre sur le marché des produits de meilleure qualité nutritionnelle. Ce travail de thèse a eu pour objectif de déterminer si cette amélioration de la qualité nutritionnelle était compatible avec le maintien de la qualité sensorielle. La première étude portait sur l’impact des réductions en lipides et/ou en sucres sur l’appréciation et la perception sensorielle de neuf catégories de biscuits et gâteaux. Les résultats montrent que les enfants perçoivent peu de différences et apprécient généralement autant les variantes réduites que les variantes standards. Pour les produits réduits sans ajout de polyols, les adultes déprécient principalement les variantes qui sont perçues moins sucrées et parfois également moins grasses et/ou différentes d’un point de vue textural. De plus, les réductions en sucres sont plus perceptibles que les réductions en lipides et à taux de réduction proches, les produits réduits en lipides sont moins dépréciés que ceux réduits en sucres. Les produits réduits avec ajout de polyols ne sont pas dépréciés et ne sont pas tous perçus moins sucrés.La deuxième étude s’est intéressée à deux leviers pour faire mieux accepter les produits réduits en lipides ou sucres. En exposant quasi-quotidiennement des consommateurs à des biscuits réduits d’environ 30 % en lipides ou en sucres, l’appréciation de ces produits augmente après un mois, mais davantage pour les lipides. En revanche, une exposition progressive ne montre pas d’effet sur un mois. Par ailleurs, une allégation nutritionnelle indiquant une réduction ne semble pas être un levier pour l’appréciation de biscuits et gâteaux réduits en lipides ou sucres / French biscuit producers are willing to improve the nutritional composition of their products. The objective of this work was to determine whether it was possible while maintaining the sensory quality of the reduced product.The first study dealt with the impact of fat and sugar reduction on liking and sensory perception of 9 types of biscuits and cakes. Results show that children perceived almost no difference and liked equally the standard and the fat- and/or sugar-reduced variants for most types of biscuits. For products reduced without adding polyols, adults less liked fat- or sugar-reduced variants than standard ones mainly when they were perceived as less sweet, and to a lesser extent as less fatty and/or as different in terms of textural aspects. Furthermore, a reduction in fat content was more difficult to perceive than a reduction in sugar content. With similar levels of reduction, fat-reduced products were less disliked than sugar-reduced ones. Sugar-reduced biscuits with an addition of polyols were not disliked and some of them were not perceived as less sweet than standard biscuits.The second study was about two strategies to promote consumer acceptance for fat- or sugar-reduced products. On the one hand, some consumers were exposed almost daily to -30 % fat- or sugar-reduced biscuits. After a month of exposure, reduced variants were more appreciated than before exposure, but it was more significant for fat reduction. On the other hand, no difference of liking was observed after a month of stepwise exposure. Besides, a nutritional claim indicating the fat or sugar reduction does not seem to be efficient to increase liking for fat- or sugar-reduced biscuits and cakes