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Investigation of rheological properties and conformation of cassava starch in zinc chloride solution
Author(s) -
Chen Xiaodong,
Liu Peng,
Shang Xiaoqin,
Xie Fengwei,
Jiang Huihua,
Wang Jie
Publication year - 2017
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.201600384
Subject(s) - rheology , zinc , starch , chloride , chemistry , materials science , food science , chemical engineering , polymer science , nuclear chemistry , composite material , organic chemistry , engineering
Zinc chloride aqueous solution is a non‐derivatizing solvent for starch, and can be used as a media for homogeneous starch modification. Here, the rheological properties of starch in ZnCl 2 aqueous solution under different conditions are considered. Specifically, a large number (120) of viscosity–shear‐rate curves for starch–ZnCl 2 solutions with different starch contents, ZnCl 2 concentrations, and temperatures were obtained and modeled using a master curve method. In particular, the power‐law index ( n ) from the modeling could accurately classify the starch molecules in ZnCl 2 aqueous solutions into an insoluble state, a dilute state, a semi‐dilute state, and a sticky state, reflecting the different degrees of chain interactions in the solution. In particular, the sticky state would be mostly likely be controlled by the zinc–starch complex, which made the rheological behavior entirely different from that at low ZnCl 2 concentrations. The knowledge obtained from this study can be used to guide the homogeneous modification of starch and the fabrication of starch‐based materials using green solvents such as aqueous ZnCl 2 with desired properties.