LINEAR VISCOELASTIC BEHAVIOR OF COMMERCIAL AND MODEL MAYONNAISE

Oscillatory shear experiments in the linear viscoelastic domain were carried out on four commercial brands of mayonnaise and three samples of model mayonnaise with different oil contents (75, 77.5, and 80% w/w), at temperatures between 10 and 40-degrees-C. A power-law relationship between complex viscosity and frequency was found for all the samples. The power-law indexes were compared with those obtained from stress relaxation tests carried out on commercial mayonnaise. No significant differences between them were found. Shear strain in the nonlinear viscoelastic region, above a certain threshold value, produced an irreversible structural breakdown of the emulsion. This was dependent not only on the magnitude of the strain but also on the elapsed time since the deformation started.