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Dynamic Rheology of Rice Starch‐Galactomannan Mixtures in the Aging Process
Author(s) -
Kim Chion,
Lee SamPin,
Yoo Byoungseung
Publication year - 2006
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.200500408
Subject(s) - locust bean gum , guar gum , starch , rheology , guar , food science , chemistry , materials science , composite material , xanthan gum
The effect of galactomananns (guar gum and locust bean gum) at different concentrations (0, 0.2, 0.4, 0.6 and 0.8%, w/w) on the dynamic rheological properties of aqueous rice starch dispersions (5%, w/w) was investigated by small‐deformation oscillatory measurements during aging. Magnitudes of storage ( G ′) and loss ( G ′′) moduli measured at 4°C before aging increased with the increase in gum concentration in the range of 0.2–0.8%. G ′ and G ′′ values of rice starch‐locust bean gum (LBG) mixtures, in general, were higher than those of rice starch‐guar gum mixtures. G ′ values of rice starch‐guar gum mixtures as a function of aging time (10 h) at 4°C increased rapidly at initial stage and then reached a plateau region at long aging times. However, G ′ values of rice starch‐LBG mixtures increased steadily without showing a plateau region. Increasing the guar gum concentration resulted in an increase in plateau values. The rate constant ( K ) for structure development during aging was described by first‐order kinetics. K values in rice starch‐guar gum mixtures increased with the increase in guar gum concentration. G ′ values of rice starch‐galactomannan mixtures after aging were greater than those before aging.