Spinnability of Starch Pastes

Abstract

The spinnability was studied with a series of starch pastes prepared from starch granules of potato (2.0-5.0% (w/v)), waxy corn, corn and wheat (5.0% (w/v)). Potato starch pastes were heated at 80°C and 98°C for 2, 30 and 90min, and the other starch pastes were heated at 98°C for 2min. The spinnability was measured by using a Rheolometer, while the measurements were made to obtain flow properties and dynamic viscoelasticity of the pastes so as to compare the spinnability of the samples. The spinnability of potato starch pastes was greater than that of waxy corn starch pastes under the same concentration and heating conditions. However, corn starch and wheat starch pastes showed a very little spinnability. At the same heating conditions, the spinnability of potato starch pastes in different granule concentrations increased while their consistency indices K, the dynamic moduli G' and the dynamic viscosities η' increased. The spinnability also closely related to the relaxation time τ for the samples showing the similar values of the dynamic viscosity η'. Consequently, a linear relationship could be obtained between the spinnability and the product of n' and τ for the starch pastes.