Inhomogeneous distribution of fat enhances the perception of fat-related sensory attributes in gelled foods

This study investigated the effect of the spatial distribution of fat on the perception of fat-related sensory attributes using a model system that consisted of layered agar/gelatin gels containing oil-in-water (O/W) emulsion droplets dispersed in the gel matrix. Four layers of gel varying in the amount of emulsion droplets were combined to prepare samples with homogeneous and inhomogeneous distributions of fat (emulsion droplets). The composition of the gels was optimized to obtain samples with comparable mechanical properties. A significant enhancement of mouthfeel attributes such as spreadable and melting was observed in samples with inhomogeneous distributions of fat in a Quantitative Descriptive Analysis (QDA) panel. Inhomogeneous samples with large differences in fat content between layers were perceived more spreadable and melting than the sample in which fat was homogeneously distributed. Creaminess ratings tended to increase as the difference in fat content between layers increased in the inhomogeneous samples. Additionally, the position of the high-fat layers in the sample affected the perception of fat-related attributes. The sample with high-fat layers on the outside had the highest ratings for all mouthfeel and afterfeel attributes. The enhancement of fat-related attributes by an inhomogeneous distribution of fat depended on the overall fat content. The enhancement at 15 wt% fat was larger than that at 5 wt% fat. We suggest that the modulation of the spatial distribution of fat can be used to reduce the fat content of food products without causing undesirable changes in the sensory properties