Evaluating the Property and Stability of Mayonnaise and Influences of Adding Vinegar before and after Emulsification.

Many processing parameters influence the physical properties and stability of mayonnaise and producing stable mayonnaise is still more of an art than a science today. The timing of adding vinegar is critical, but its detailed influences and the underlying mechanism remain unclear. In this work, the total vinegar added in mayonnaise preparation was divided into two portions, with the first portion added before the emulsification and the second added after emulsification. Adding vinegar before the emulsification slightly decreased the lightness but increased the greenness and yellowness in color measurement. It decreased viscosity and storage modulus and increased droplet size and extractable oil percentage. These influences became greater when more vinegar was added before the emulsification and persisted after seven days of storage. These influences might correlate with the structural change of egg yolk granules in mayonnaise processing. Adding vinegar led to increased particle size and decreased emulsification ability of egg yolk granules. There is also no definitive way to test the stability of a food emulsion. One way to reliably break emulsions is through the use of fluctuating temperatures. By rapidly freezing and thawing the emulsions ice crystals can form and break the interfacial film that allows emulsions to be possible. The findings here better understand the physical processes involved in the mayonnaise emulsion formation and stabilization.