Author/Authors :
Jose R. Moreira، نويسنده , , F. Chenlo، نويسنده , , M.D. Torres، نويسنده ,
Abstract :
The influence of the addition of NaCl (0.6, 1.2, 1.8%, w/w), sucrose (0.6, 1.8, 3.4, 5.0%, w/w), chestnut starch (5.0, 10.0, 15.0%, w/w) and NaCl–sucrose mixtures (0.6–0.6, 1.8–1.8%, w/w) on the rheological properties of chestnut flour (CF) doughs were studied using a controlled-stress rheometer. Mixing and complete tests were achieved by the Mixolab® apparatus. Shear (0.01–10 s−1), oscillation (1–100 rad s−1), temperature sweep (30–100 °C) and creep-recovery (loading of 50 Pa) measurements were performed. Steady-flow curves exhibited a Newtonian plateau at <0.1 s−1 that was shifted to lower shear rates with the additives. Apparent viscosities were satisfactorily fitted using Cross model. Moduli values of storage and loss decreased, at constant angular frequency, with increasing additives. Gelatinization temperatures were slightly modified. Creep-recovery data, fitted using Burgers model, showed that the elasticity was low (23.0%) and doughs with chestnut starch presented the highest recoverable proportion (45.6%).
Keywords :
Creep , Mixing , Chestnut starch , viscoelasticity , Gelatinization , Steady-shear curves