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Gelatinization of Hypochlorite Oxidized Maize Starch in Aqueous Solutions
Author(s) -
Kantouch F.,
Tawfik S.
Publication year - 1998
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/(sici)1521-379x(199803)50:2/3<114::aid-star114>3.0.co;2-7
Subject(s) - sodium hypochlorite , starch , sodium hydroxide , chemistry , thixotropy , aqueous solution , hypochlorite , rheology , alkali metal , chlorine , sodium , chemical engineering , inorganic chemistry , materials science , organic chemistry , engineering , composite material
The effect of concentration of sodium hydroxide on the gelatinization of hypochlorite oxidized maize starches was thoroughly investigated. It was found that oxidation of starch increases its affinity towards gelatinization with alkali solutions at room temperature. Clear gelatinized starch could be obtained immediately at a concentration of sodium hydroxide of 1% on using hypochlorite oxidized starches irrespective of their degree of oxidation. While in case of native maize starch clear gelatinized paste was obtained at a concentration of 4% or more. The rheological properties of the alkali gelatinized starches were determined after 2 h of preparation and after storing of their pastes for 4 days. Hypochlorite oxidation of starch changes its rheological characteristics from non‐Newtonian thixotropic to non‐Newtonian pseudoplastic. The suitability of one g/l active chlorine oxidized maize starches gelatinized at 25°C, under the influence of different concentrations of sodium hydroxide, either alone or in admixture with sodium alginate as thickeners in printing pastes of vat dyes was thoroughly investigated.