Fat Perception: How Sensitive are We?

We evaluate how perceptual discrimination depends on fat content for a range of liquid and semi‐liquid foods. We also investigate the role played in fat discrimination by olfaction, vision and taste and how sensory results can be related to physicochemical characteristics. The food matrices under investigation were all made of a continuous water phase containing various amounts of fat (sunflower oil‐in‐water emulsions, flavored and unflavored milk, stirred yoghurt and emulsified white sauce). We find that the sensory fat discrimination varies strongly depending on the food and the tasting conditions. Here, the fat content of low viscosity samples could be reduced or increased by 50%, without significantly impacting fat perception. However, the fat difference threshold is much lower for high viscosity samples. We also found that our sensory results are not related to the rheological properties. However, tribology data on stirred yoghurts were found to be valuable instrumental parameters for the study of the interactions between food composition and sensory perception. Practical Applications Fat content reduction in foods is required to reduce daily fat intake. However, this involves changes in the global perception of products. This work evaluates the ability to discriminate fat content for diverse food matrices and components which could impact it (ingredients or physicochemical characteristics). Managing the impact of these different factors on fat perception may help to develop reduced fat products with optimized sensory properties.