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Dynamic Rheological and Textural Properties of Acorn ( Quercus brantii Lindle.) Starch: Effect of Single and Dual Hydrothermal Modifications
Author(s) -
Molavi Hooman,
Razavi Seyed M. A.
Publication year - 2018
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.201800086
Subject(s) - starch , chewiness , rheology , dynamic mechanical analysis , viscoelasticity , dynamic modulus , materials science , shear thinning , mineralogy , chemistry , composite material , food science , polymer
In this paper, the small deformation (small amplitude oscillatory shear rheology) of native and hydrothermally modified acorn starch pastes as well as large deformation (texture profile analysis) of starch gels are investigated. Native starch presents the greatest values obtained by amplitude sweep test followed by annealed starch while heat‐moisture treated starch showed the minimum values. The values for dually modified starches are between those of single modifications. The loss tangent values at the linear viscoelastic region are in the range of 0.03–0.06, demonstrating the dominance of elastic behavior of native and modified starch dispersions. The magnitudes of storage modulus ( G ′) are greater than those of loss modulus ( G ″) over the frequency range (0.63–62.8 rad s −1 ). Native starch presents the most loss tangent values (tan δ) at 6.28 rad s −1 , while HMT‐treated starches shows the smallest. The ability of gel formation reduces slightly in hydrothermal treatments. The hardness, adhesiveness, cohesiveness, springiness index, gumminess, and chewiness index of acorn starch were 261.3 g, 0.64 mJ, 0.96, 0.98, 252.1 g, and 248.0 g, respectively. Among different hydrothermal treatments, annealing did not alter the textural parameters of native starch significantly ( p > 0.05).