Thixotropic properties of the normal potato starch - Locust bean gum blends

- The pastes were rheologically unstable, non-Newtonian, shear thinning fluids.
- Non-pasted granules evoked thixotropy while pasted granules led to antithixotropy.
- Concentration of polysaccharides, pasting temperature and measuring method influenced the results.

The aim was to study the rheological, especially thixo- and antithixotropic properties of normal potato starch (NPS) with the addition of locust bean gum (LBG) depending on the pasting temperature, the starch concentration and the amount of LBG. All the pastes under study were rheologically unstable, non-Newtonian, shear thinning fluids. The increase in the LBG content obstructed pasting of the starch granules and increased viscosity of the pastes. In a vast majority of cases obstruction in swelling granules and, hence, higher amount of non-pasted granules evoked thixotropy. In turn, a higher numbers of well swollen granules and, hence pasted granules led to antithixotropy. Apart from the concentration of both polysaccharides and pasting temperature the results depended also on the measuring method applied.