This work describes the sensory properties of microparticulated whey protein (MWP) particles in relation to their rheological and tribological properties. The aim of this work is to obtain a better understanding of the sensory perception of MWP particles compared to oil droplets in liquid and semi-solid matrices. We used liquid MWP-o/w emulsions with controlled viscosities and semi-solid MWP-emulsion-filled gelatin gels as food model systems. Consistent with our previous findings, MWP showed good lubrication properties probably due to ball bearing mechanism in both liquid and semi-solid systems. Sensory results (QDA) revealed that small MWP particles contributed to perception of creaminess due to their lubrication property. Large MWP contributed to the rough and powdery perception, and thus suppressed perception of creaminess. MWP did not contribute to perception of fattiness in contrast to oil droplets. The perception of fattiness was probably related to the film formation properties of oil. As a result, MWP in liquid emulsions were generally perceived as rough but not creamy. In the case of MWP-emulsion-filled gels, although the gel matrix restrained the lubrication function of MWP particles, it also masked the rough perception of big MWP particles. Due to the combined effect of both oil droplets and MWP particles, MWP in gels resulted in an overall positive effect on the creamy perception. We conclude that MWP contributes to fat-related sensations in a different way than oil does. The perception of MWP particles is related to the size of the particle as well as the properties of the surrounding matrix.
- Particle size