Stability and physicochemical properties of model salad dressings prepared with pregelatinized potato starch.

The effects of pregelatinized potato starch concentration (PSC) ranged from 0 to 5 wt% on the physical stability, color, rheological, textural, and sensory properties of model salad dressings prepared with 2 wt% dried egg yolk (DEY) or sodium caseinate (SC) were explored. All dressings showed shear-thinning behavior with yield stress. Raising PSC increased storage (G') and loss (G") moduli decreasing loss tangent (tanδ) and samples containing ≥ 3 wt% starch showed a weak gel-like (tanδ<1) response. A generalized Cox-Merz rule was applicable to indicate shear/strain sensitivity of the dressings structures. Rheological characterization based on Bohlin's parameters (A, z) was useful for distinguishing physical stability of dressings made with different formulations. Changes in color were generally very small and mainly PSC-dependent. Correlation analyses revealed that sensory descriptors could be satisfactory modeled with the appropriate instrumental data. Overall, the results proved that pregelatinized potato starch may be suitable ingredient in low-fat dressings applications.