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Optimizing the Conditions for Starch Dry Phosphorylation with Sodium Mono‐ and Dihydrogen Orthophosphate under Heat and Vacuum
Author(s) -
Sitohy Mahmoud Z.,
Labib Salah M.,
ElSaadany Said S.,
Ramadan Mohamend. F.
Publication year - 2000
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 - 10.1002/1521-379x(200006)52:4<095::aid-star95>3.0.co;2-x
Subject(s) - amylopectin , starch , amylose , chemistry , phosphate , sodium , inorganic chemistry , nuclear chemistry , organic chemistry
Starch was phosphorylated by reaction with mono‐ and disodium hydrogen orthophosphate under dry conditions in a vacuum oven at 150‐180 °C (800 mbar). Studying the different factors affecting the reaction showed that the optimal conditions for starch phosphorylation in the monoester form were: 3 h reaction time, 160 °C reaction temperature and pH 6. The different types of starch gave different degrees of substitution; and amylose bound a higher amount of phosphate than amylopectin under similar reaction conditions. Both ash content and acidity of the phosphorylated starch products increased proportionally with the increase in the degree of substitution while the pH of the different modified starch products was nearly in the same range (pH 6.55—6.75).