Physiological mechanisms explaining human differences in fat perception and liking in food spreads-a review

Background: Fat perception and liking are the subjects of growing interest from industries and the scientific community to reduce the fat content in food products while maintaining consumers' liking. Scope and approach: In this review, the different physiological parameters involved in fat perception and fat liking for food emulsions are explored, focusing on spreads. A deeper analysis of the physiological mechanisms occurring during the melting and inversion phases, followed by bolus formation, mouth coating and oral clearance, allows an examination of the links between food composition, food structure, oral physiological parameters, fat perception and liking. Key findings and conclusions: Fat perception is a multimodal sensation involving olfactory, gustatory and tactile cues. The main sensory descriptors associated with fat liking are creaminess, spreadability and aroma perception. During the melting and inversion phases, oral volume, saliva flow and tongue-palate compression contribute to the heat transfer and cooling effect, leading to the first sensory perception. Global acceptability is also driven by the mouthfeel sensation perceived after swallowing. Mouthfeel is a consequence of the bolus formation, mouth coating and oral clearance processes that are dependent on both emulsion composition and oral physiological parameters (saliva flow, saliva composition, fungiform papillae). Understanding the physiological mechanisms controlling fat perception can lead to a better understanding of the consumer's preference and liking for food emulsions.