Influence of temperature, mono- and divalent cations on dilute solution properties of sage seed gum

The functional properties of food hydrocolloids are remarkably affected by the quality of solvent/cosolutes and temperature in a food system. In this paper, dilute solution properties of sage seed gum (SSG) as a function of salt type (NaCl, KCl, MgCl2 and CaCl2), salt concentration (10, 50, 100 and 200mM) and temperature (25, 45 and 65°C) were investigated. Among various models, Higiro model showed a higher performance to determine intrinsic viscosity of SSG at all temperatures and cosolutes. From 25 to 65°C for every 20°C rise in temperature, intrinsic viscosity decreased about 18.99 and 63.86%, respectively. The divalent cations had more reduction effect on intrinsic viscosity than monovalet cations. More flexibility of SSG in monovalent salts solutions compared with divalent ones was observed. A high value for activation energy (2.53×10(7)J/kgmol) and chain flexibility (3046.45) of SSG was obtained, which was higher than many hydrocolloids. The shape factor of SSG macromolecules at 25-65°C was an oblate or prolate and for all used cosolutes, the shape was roughly found to be ellipsoidal.