Premium
RHEOLOGICAL BEHAVIORS OF GINSENG EXTRACTS IN STEADY AND DYNAMIC SHEAR
Author(s) -
YOO B.
Publication year - 2003
Publication title -
journal of texture studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.593
H-Index - 54
eISSN - 1745-4603
pISSN - 0022-4901
DOI - 10.1111/j.1745-4603.2003.tb01055.x
Subject(s) - rheology , shear thinning , activation energy , viscosity , thermodynamics , arrhenius equation , apparent viscosity , relative viscosity , materials science , ginseng , chemistry , atmospheric temperature range , analytical chemistry (journal) , chromatography , composite material , organic chemistry , medicine , physics , alternative medicine , pathology
The steady and dynamic rheological properties of ginseng extracts were evaluated at 60.6–69.8% total solid contents. Ginseng extracts at 20C showed a very low shear‐thinning flow behavior (n = 0.94 ‐ 0.98) with low consistency index (K = 0.39 ‐ 5.02 Pa.s n ). Over the temperature range of 5 ‐ 50C, the magnitudes of K and apparent viscosity (η a,100 ) decreased with increase in temperature. The apparent viscosity obeyed the Arrhenius temperature relationship; the activation energies for flow of ginseng extracts were in the range of 56.9 ‐ 85.9 kJ/mol. The exponential type relationship between total solids and apparent viscosity was found to be more suitable than a power type relationship. Viscosity data at various temperatures could be reduced to a composite viscosity curve using a reduced apparent viscosity (η aR ). Magnitudes of storage (G′) and loss (G″) moduli increased with increase in total solids. Magnitudes of G″ were much higher than those of G′ over the entire range of frequencies (ω) with the high dependence on ω.