Influence of Selected Salts and Sugars on the Rheological Behavior of Quince Seed Mucilage

Properties of solvent/cosolute in a food system obviously can influence the rheological properties of hydrocolloids. In this work, the impact of various concentrations of some sugars (sucrose and glucose at ۱۰, ۲۰, and ۳۰% w/w concentration) and salts (CaCl۲ and NaCl, ۵۰, ۱۰۰, and ۱۵۰ mM) on the rheological properties of Quince Seed Mucilage (QSM) were investigated. QSM produced high viscosity dispersion with yield stress, which was affected by concentrations and types of salt and sugar. The salts altered the electrostatic interactions between the QSM chains and led to the viscosity reduction. Increasing the salt concentration, decreased the yield stress (τ۰) and consistency coefficient (k) values, but led to increase in the flow behavior index (n) value. Sucrose and glucose increased the apparent viscosity of QSM dispersions. High sugar concentrations resulted in higher viscosity. Assessment of the time-dependent flow behavior of QSM dispersions proved that the structural kinetic model had the best data description. All the samples showed thixotropic behavior. The Atomic Force Microscope (AFM) results exhibited a proper understanding of the chain interactions of QSM and changes in the flow behavior. The results of this research showed that CaCl۲ and sucrose had more pronounced effect on the rheological properties of QSM.

Keywords:

Hydrocolloid , Quince mucilage , Rheology , Structural kinetic model.