Rheological properties of low methoxyl pectin

The fundamental rheological properties of low methoxyl pectin(LMP) and the effects of factors, such as temperature, shear rate, pH value, metal ions, sugar on rheological properties were researched with AR-500-type rheometers. Results indicate that LMP solution has typical shear-thinning property, and the rheological properties are influenced by temperature, shear rate, pH value, et al. The increasing of temperature and pH value can reduce the viscosity of LMP. The effect of shear rate is relation to the concentration of LMP. At the low concentration(0.3%), shear-thinning property of LMP will be more notability in the low shear rate(0～200 s^-1) and the rheological behavior will be change to shear-thick property in high shear rate(400～700 s^-1). At the high concentration(1%, 2%), the LMP will change to Newton liquid gradually with the increasing of shear rate. Metal ions obviously improve the viscosity of LMP solution, and the ability is correlated to the concentration of metal ions.