TY - JOUR
T1 - Rheological and thermal effects of galactomannan addition to acorn starch paste
AU - Kim, W. W.
AU - Yoo, B.
PY - 2011/4
Y1 - 2011/4
N2 - Effect of galactomannans (guar gum and locust bean gum) at different concentrations on rheological and thermal properties of acorn starch pastes was examined. Steady and dynamic shear rheological tests indicated that the magnitudes of consistency index (K), apparent viscosity (ηa,100), Casson yield stress (σoc), dynamic moduli (G′, G″), and complex viscosity (η*) of acorn starch-galactomannan mixtures were much higher than those of the control (0 g/100 g gum concentration), and that these values also increased with an increase in gum concentration. At temperatures ranging from 25 to 70 °C, the effect of temperature on ηa,100 was well described by the Arrhenius equation. In addition, DSC studies showed that the presence of galactomannans resulted in an increase in the transition temperatures (To, Tp, and Tc) and a decrease of the gelatinization enthalpy (ΔH). In general, these results suggest that the presence of galactomannans in acorn starch modifies the rheological and thermal properties, but that these modifications are dependent on the gum type and gum concentration.
AB - Effect of galactomannans (guar gum and locust bean gum) at different concentrations on rheological and thermal properties of acorn starch pastes was examined. Steady and dynamic shear rheological tests indicated that the magnitudes of consistency index (K), apparent viscosity (ηa,100), Casson yield stress (σoc), dynamic moduli (G′, G″), and complex viscosity (η*) of acorn starch-galactomannan mixtures were much higher than those of the control (0 g/100 g gum concentration), and that these values also increased with an increase in gum concentration. At temperatures ranging from 25 to 70 °C, the effect of temperature on ηa,100 was well described by the Arrhenius equation. In addition, DSC studies showed that the presence of galactomannans resulted in an increase in the transition temperatures (To, Tp, and Tc) and a decrease of the gelatinization enthalpy (ΔH). In general, these results suggest that the presence of galactomannans in acorn starch modifies the rheological and thermal properties, but that these modifications are dependent on the gum type and gum concentration.
KW - Acorn starch
KW - Gum
KW - Rheological property
KW - Thermal property
UR - http://www.scopus.com/inward/record.url?scp=78650517562&partnerID=8YFLogxK
U2 - 10.1016/j.lwt.2010.11.009
DO - 10.1016/j.lwt.2010.11.009
M3 - Article
AN - SCOPUS:78650517562
SN - 0023-6438
VL - 44
SP - 759
EP - 764
JO - LWT
JF - LWT
IS - 3
ER -