Rheology of commercial chestnut flour doughs incorporated with gelling agents

Abstract

The rheological properties of chestnut flour (CF) doughs incorporated with agar, hydroxypropylmethyl cellulose (HPMC) and xanthan at different concentrations (0.5, 1.0, 1.5, 2.0%, flour basis) were determined at 30 °C using a controlled stress rheometer. The mixing behavior at the same temperature was achieved by the Mixolab® apparatus. The tests conducted in the rheometer were shear (0.01–10 s−1), oscillatory (1–100 rad s−1 at 0.1% strain), creep-recovery (loading of 50 Pa for 60 s) and temperature sweep (30–100 °C) measurements. These rheological properties were significantly modified by the type and content of gelling agent added. The values of apparent viscosity in all tested shear rate range as well as the values of storage (G′) and loss (G″) moduli of CF doughs in the tested angular frequency decreased with increasing agar and HPMC concentration and increased with xanthan addition. Flow curves and storage and loss moduli of assayed doughs were satisfactorily fitted using Cross model and a potential model, respectively. The initial gelatinization temperature decreased with agar and increased with xanthan as well as the gelatinization temperatures range with HPMC addition was shorter. This pasting trend was also noticed using Mixolab®. Creep-recovery data, successfully fitted using Burgers model, showed that elasticity of doughs improved significantly with HPMC and xanthan addition.