Predictive model for viscosity development of modified rice starch suspension under unsteady temperature change

• Published in: Journal of food engineering Vol. 209; pp. 45 - 51
• Main Authors: Anuntagool, J., Alvarez, G., Flick, D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2017; Elsevier
• Subjects: dispersions; Gelatinization; Granule growth; heat; heat exchangers; Kinetics; Life Sciences; Modeling; Rheology; rheometers; Rice starch; starch; temperature; viscosity; Granule growth; Kinetics; Gelatinization; Rheology; Rice starch; Modeling; gélatinisation; gelatinization; rheology; cinétique; rhéologie; kinetics
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2017.04.012

This study aimed to establish a predictive model that takes into account the effect of thermal history on the viscosity development of modified rice starch dispersions subject to unsteady temperature change. Experiments were conducted in a modified rheometer allowing fast heating/cooling similar to an industrial heat exchanger. The model was developed on two assumptions: (1) starch granule growth is responsible for the viscosity evolution and (2) thermal history controls the gelatinization and the granule growth of the starch dispersion. To identify the rheological parameters, modified rice starch dispersions (3%–5%) were heated from 20 °C to temperatures normally used in heat exchangers (105–120 °C) in a Couette rheometer under high heating rates (0.5–2.0 °C s−1) and shear rates (400 and 800 s−1). The predictive model was successfully employed to predict the viscosity of modified rice starch dispersion gelatinized under vigorous conditions. •3–5% gelatinized modified rice starch suspension flow behaviour follows pseudoplastic power law model.•Modified rice starch granule growth follows second order kinetics and the growth rate follows the Arrhenius relationship.•Flow behavior index of gelatinized modified rice starch does not vary with concentration, mechanical and thermal history.