Effects of casein-to-whey protein ratio, fat and protein content on sensory properties of stirred yoghurt

The effects of fat, protein and casein-to-whey protein ratio on sensory properties of stirred yoghurt, and interactions between these, were examined using descriptive analysis. Furthermore, the possible enhancement of fat-related sensory properties by variations in protein content and whey protein addition was studied. Variations in fat content (CF = 0.1–12.0%), protein concentration (CP = 3.5–6.0%) and casein-to-whey protein ratio (c/w = 80/20, 60/40 and 40/60) were studied. Results demonstrated decreasing effects concerning the attributes aromatic, sour and astringent, and increasing effects regarding graininess and yellow colour, with decreasing c/w and increasing CP. An increase in CF reduced the effect of c/w. Creamy taste and texture, visual and textural viscosity, and fatty mouth feel, increased with increasing CF, CP and c/w. The effect of CP decreased with increasing CF. An increase in CP enhanced fat-related sensory properties, whereas whey protein addition had the opposite effect.