SD powder mucilage samples were re-suspended in de-ionized water using a magnetic stirrer (Thermo Scientific, Telesystem 15) at 500 rpm at 24 ± 1 C for 90 min. Samples with 0.06 g/mL were prepared to study the effects of changes in pH, temperature and ionic strength on the rheological behavior of mucilage. All rheological measurements were performed in a stress controlled rheometer (AR-G2, TA Instruments) using a cone and plate geometry (d ¼ 60 mm,1 angle) with a Peltier plate system attached to a circulating water bath (Haake, Germany, Mod. F3T). Samples were characterized under simple shear flow. The viscoelastic properties,
storage (G0) and loss modulus (G00) were measured under small-amplitude oscillatory with frequency range from 0.1 to 200 rad/s. Finally, the first normal stress difference under steady-shear (N1) was measured to determine the elastic properties under shear flow.