Factors affecting the perception of creaminess of oil-in-water emulsions

Rheological properties and particle size distributions of butter fat-in-water emulsions stabilized by sodium caseinate (2–4 wt%) have been investigated in relation to the texture descriptors ‘taste’, ‘thickness’ and ‘creaminess’. The effects of oil droplet size (0.5 and 2 μm), oil volume fraction (5–20 vol%), and the addition of low-methoxy pectin or xanthan on texture perception have been evaluated at various concentrations of the hydrocolloids (0.03–1 wt%). Particular sets of conditions were chosen so that the samples had the same apparent viscosities at high shear-rate (50 s−1). Sensory panel results show that the perception of all three descriptors was significantly influenced by the rheology and the fat content, with higher ratings of all three descriptors scored for samples with higher viscosity and higher volume fraction. Discrimination between 5 and 20 vol% oil samples was stronger in the more viscous samples. Creaminess perception appeared to be more enhanced by a higher viscosity than by a higher volume fraction of oil. Some correlations between the different texture descriptors and the shear-thinning rheology of the samples were detected. Changing the oil droplet size from 0.5 to 2 μm had no significant influence on the perceived perception of taste, thickness and creaminess.