The dilute solution properties of starches from two canary seed varieties (C05041 and CDC Maria), as well as wheat starch (WS) in DMSO/H2O (9/1 v/v %) solution, as a function of salt type (NaCl and CaCl2) and salt concentration (5–100 mM) at different temperatures (25, 35, 45, and 55 °C) are investigated. Various models, i.e., Huggins, Kraemer, Higiro, and Tanglertpaibul and Rao equations are applied for estimating the intrinsic viscosity [η] of the canary seed starches (CSSs) and WS in dilute solution. Of all the examined models, the Higiro 1 model shows a higher performance for determining the intrinsic viscosity of the selected starches at all temperatures and ionic strengths. The intrinsic viscosity [η] of the selected starches decreases significantly with an increase in ionic strength, at all examined temperatures. The results show that the influence of NaCl on the [η] reduction of CDC Maria starch and WS is more than for C05041 starch. The shape functions of the selected starches at 25 °C are spherical; however, with increasing ionic strength and temperature from 25 to 55 °C, the CSSs and WS samples take an ellipsoidal shape. The Berry number and the slope of the master curve reveal that CSSs and WS solutions at all temperatures and salt concentrations are in the dilute domain and no molecular entanglements occur.

Keywords