Effect of the Addition of High Methoxy Pectin on the Rheology and Colloidal Stability of Acid Milk Drinks

Abstract

The effect of high methoxy pectin on the behaviour of model acid milk drinks has been investigated using viscometry, laser diffraction size measurement and microelectrophoresis. The results of these different tests are interpreted using the theory of colloidal stability. With increasing pectin concentration, the behaviour changes from flocculated with few particles below 0.2µm diameter and shear thinning, time-dependent rheology to non-flocculated, many sub 0.2µm particles and low viscosity with Newtonian rheology. With even higher pectin concentrations, the acid milk drink remains non- flocculated, but with increasing viscosity and close to Newtonian rheology.