The relationship between entanglement concentration and physicochemical properties of potato and sweet potato starch dispersions

Entanglement concentration (c(e)) is defined as the onset of overlap and interpenetration of random-coil chains in a polymer solution and is important in determining rheological, dynamic and fracture properties. However, few studies have reported in detail how c(e) influences physicochemical properties of starch dispersions. So, the effects of c(e) on the physicochemical properties of the potato and sweet potato starch dilute and semi-dilute dispersions were investigated. The results showed that for the two starch dispersions with concentrations c(e), the gelatinisation temperature increased more significantly with increasing concentrations, and storage modulus increased faster than loss modulus with increasing frequency. The potato starch dispersion with concentrations c(e) possessed higher entanglement density of the chain segments. The two starch dispersions with concentrations >c(e) exhibited shear thinning with increasing frequency. The two starches could only form film at concentrations c(e). So, c(e) will be a suitable concentration for regulating the concentration of starch dispersions to obtain the expected physicochemical properties.