SALAD DRESSING CHARACTERISTICS
A salad dressing is an "oil in water" emulsion, where oil is the discontinuous phase and water is the continuous phase. Salad dressing is defined by the FDA as a semisolid emulsified food with the same ingredients and optional ingredients as mayonnaise with the exception of the inclusion of a cooked or partially cooked starch paste. The typical ingredients of salad dressing are acetic acid, salt, sugar, water and vegetable oil. There are two types of salad dressing, pourable and spoonable.
The original spoonable dressing was mayonnaise, which must contain at least 75% oil.
These two types of salad dressings vary in flavor, chemical and physical properties ( especially viscosity). The pourable dressing may either be sold in a homogeneous phase or in two phases. The two-phase salad dressings are separated by water and oil and will require shaking prior to use. The typical pH of these products ranges from 3.5 to 3.9. However, "spoonable" salad dressings contain less acid than the pourable salad dressings, causing less microbial stability. The primary preservatives used to control microbial spoilage are sodium benzoate and or potassium sorbate. Refrigerating the spoonable salad dressing will also help control microbial contamination. Aseptic processing and packaging also play a major role in the prevention of contamination. However, in most salad dressings, microbial spoilage is not a major issue.
The production of a salad dressing requires the use of a colloid mill or a homogenizer (low fat dressings). The colloid mill uses the shear and turbulence of liquid passing between two surfaces that are closely spaced, to mix the ingredients. A colloid mill is used to mix high viscous materials, while a pressure homogenizer is used to mix lower viscous materials. The ingredients of the fluid are thoroughly mixed by a homogenizer when it passes through an orifice at high pressures and speeds.
In the production of standard salad dressing, the vinegar, salt, starch and water are heated to approximately 90C. Once a starch paste has formed, this mixture is cooled and then eggs, sugar, spices and oil are added. This mixture is then passed through the colloid mill prior to packaging.
Formulations for Pourable Dressings of Differnt Fat contents:
Pourable dressings have less oil than spoonable dressings and generally contain xanthan gum as a replacement for oil in Mayonnaise and starch in Salad Dressing. Some typical formulations are tabulated below.
| Ingredient | 40% fat pourable dressing | 30% fat pourable dressing | 20% fat pourable dressing |
| Oil (%) | 40 | 30 | 20 |
| Water (%) | 35.2 | 45.2 | 55.2 |
| Vinegar (%) | 8 | 10 | 10 |
| Sugar (%) | 10 | 10 | 10 |
| Salt (%) | 2 | 2 | 2 |
| Xanthan gum (%) | 0.3 | 0.3 | 0.3 |
| Egg yolk solids (%) | 4.5 | 4.5 | 4.5 |
Spices are added to taste depending on the type of dressing.
French, Ranch and Honey Mustard
Other salad dressing recipes:
These sites offer other salad dressing recipes:
http://soyfoods.com/SimplySoy/Salads/MisoSaladDressing.html
Factors Affecting Salad Dressing properties:
Shear:
Spoonable salad dressings are non-newtonian materials that lose viscosity when subjected to shear. There are both shear thinning and time thinning fluids.