The emulsion stability, composition, structure and rheology of four different commercial italian salad dressings manufactured with traditional and light formulations were evaluated. According to the results, the fat content ranged from 8% (w/w) (light) to 34% (w/w) (traditional), the carbohydrate concentration varied between 3.8% (w/w) (traditional) and 14.4% (w/w) (light) and the pH was between 3.6-3.9 for all samples. The microscopic and stability analyses showed that the only stable salad dressing was a light sample, which had the smallest droplet size when compared with the other samples. With respect to the rheological behaviour, all the salad dressings were characterized as thixotropic and shear thinning fluids. However, the stable dressing showed an overshoot at relatively low shear rates. This distinct rheological behavior being explained by the differences in its composition, particularly the presence of a maltodextrin network.
rheology; microstructure; emulsion; salad dressing
