Premium
Rheological properties of starches from grain amaranth and their relationship to starch structure
Author(s) -
Kong Xiangli,
Kasapis Stefan,
Bertoft Eric,
Corke Harold
Publication year - 2010
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.200900235
Subject(s) - amaranth , amaranthus hypochondriacus , amylose , amaranthus cruentus , crystallinity , starch , shear thinning , dynamic modulus , rheology , materials science , dynamic mechanical analysis , botany , food science , composite material , chemistry , polymer , biology
Amaranth starch ( Amaranthus cruentus L. and Amaranthus hypochondriacus L.) in this investigation possessed a relatively small and uniform granule size of a type “A” pattern obtained by X‐ray diffraction, with the degree of crystallinity ranging from 24.5 to 27.9%. This was followed by work on steady and dynamic rheological properties on shear of seven native amaranth starches. Aqueous pastes (5% solids) exhibited shear‐thinning behavior, and the flow behavior was fitted with the Herschel–Bulkley equation (regression coefficients were over 0.99). Cultivar V69 showed much higher G ′ (storage modulus) and G ″ (loss modulus) than the other samples and produced a solid‐like gel, which could be attributed to the high amylose content of its network. Correlation analysis revealed that amylose content was positively correlated with G ′ and negatively with the loss tangent (tan δ ) of the material.