Physicochemical and Flow Characterization of a Mustard-Vinaigrette Salad Dressing

In the last decade, consumption and development of salad dressings has shown a continuous growing and their importance is increasing in Mexico and worldwide. These products are composed of oil, vinegar, spices, flavors and some hydrocolloids, among others. The formulation or specific composition is determinant on their characteristics and particularly, some physicochemical and flow properties. The objective of this study was to characterize and analyze a new salad dressing, and to observe how the incorporation of some components affects its properties. In order to study the physicochemical and flow behavior of a new mustard-vinaigrette salad dressing, different systems were elaborated. Two groups of samples were prepared; the first one included nine dressings or systems, with three different oil:vinegar rates and three mustard concentrations and stored four weeks. The second group consisted only of four systems with a constant concentration of mustard that were stored also through four weeks at two temperatures. Determinations of acidity, adhesivity, color, density, drop size, emulsion stability, flow properties, moisture, pH, retro-extrusion force, and water activity were carried out for most of the systems. Oil concentration had a significant effect on acidity, adhesivity, density, emulsion stability, flow properties, moisture, and water activity, in which the emulsifying capacity of the mustard was corroborated. The storage time showed a significant effect on adhesivity, emulsion stability, flow, luminosity and retro-extrusion properties. A modified Herschel and Bulkley model fitted better the flow behavior than other two equations. Analysis of variance allowed to know the significant effect of the studied variables on the yield stress, flow index and consistency coefficient obtained from the modified flow model.