Thermal, pasting, and rheological properties of potato starch dual-treated with CaCl2 and dry heat

Potato starch (PS) was treated separately and combinedly with 3% (w/v) CaCl2 solution at 25 °C for 5 h and dry heat (DH) at 130 °C for 1, 2, and 4 h CaCl2 treatment alone significantly increased thermal transition parameters, dynamic moduli, and shear viscosity of PS. It substantially decreased the peak viscosity and breakdown of PS during pasting, but the final paste viscosity was comparable to the control due to a higher setback. Overall, DH treatment alone reduced the thermal transition parameters, paste viscosity, dynamic moduli, and shear viscosity of PS, and prolonged heating generally caused more considerable reductions. Dual treatment with CaCl2 and DH caused the most substantial decreases in examined properties of PS. It led to a complete loss of both double–helical and crystalline order of starch granules. Therefore, cooked suspensions of dual–treated PS exhibited very weak viscoelastic or non–viscoelastic behavior and extremely low shear viscosity.