Intrinsic viscosity and molecular parameters of wheat starch-cress seed gum-sucrose mixture

Abstract

This study aimed to determine the effect of different substitution levels of cress seed gum (CSG, 0-15%) and sucrose (SUC, 0-10%) on the dilute solution properties of native wheat starch (NWS) in terms of intrinsic viscosity, Huggins constant, power-law model slope, berry number, master curve slope, critical concentration, shape factor, and swollen specific volume. In the presence of CSG, the intrinsic viscosity of NWS increased from 0.686 to 0.760 dl/g, the molecular conformation changed from random coil to rod-like, the specific swollen volume enhanced from 0.27 to 0.32 dl/g and the shape factor altered from spherical to prolate. In contrast, sucrose reduced the intrinsic viscosity of NWS to 0.379 dl/g and the specific swollen volume to 0.15 dl/g, altered the conformation to a more random coil and the shape factor to a more compact sphere. In the ternary system, the parameters were close to those of the starch-gum mixture. It can be concluded that CSG overcame the weakening effect of SUC on the NWS solution properties in the ternary system.