Effect of addition of chitosan on rheological properties of acidified milk gels

A study was made of the effect of addition of chitosan on the rheology of acidified milk gels. The milk gels were made from skimmed milk powder and were acidified at 43 °C until pH 4.5 was reached. Glucono-δ-lactone or two starter cultures, differing in the viscosity of the final product, one culture producing exopolysaccharide were used. Set- and stirred-type milk gels were studied, both with and without chitosan. Dynamic low amplitude oscillatory rheological mea surements were made during acidification, following gelation, and after 2-days storage at 5 °C. Dynamic rheology showed interesting differences between the elastic moduli of those milk gels with chitosan added and those prepared without. The syneresis and the effective viscosity after 2 days were compared for gels with or without chitosan.