Sensory and rheological characterization of low-fat stirred yogurt

With the specific objective of investigating the sensory concept of creaminess, as well as other sensory attributes obtained from descriptive analysis, a set of 25 samples of stirred low-fat yogurt were submitted to rheological (shear and imperfect squeeze flow viscometry, dynamic oscillation and Posthumus funnel) and sensory testing. Fat levels ranged from 0.3 to 3.5% and protein from 3.4 to 6.0%, and four different protein sources were employed, one being skimmed milk powder, the remaining three were milk protein preparations, one of which contained partially microparticulated whey protein (MPP). Based on averaged data from the sensory panel (n = 12), creaminess could be modeled by two other sensory descriptors, oral viscosity and smoothness (R-2 = 0.78), but was poorly modeled by the entire set of rheological data. The MPP-containing blend did best in terms of matching the creaminess scores of a control yogurt containing 3.5% fat (no additional protein added).