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Modification of Rice Starch through Thermal Treatment with Urea
Author(s) -
Abd ElThalouth I.,
ElKashouti M. A.,
Hebeish A.
Publication year - 1981
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.19810330905
Subject(s) - starch , urea , swelling , viscosity , solid state , shear viscosity , materials science , apparent viscosity , modified starch , shear rate , reaction rate , chemical engineering , nuclear chemistry , polymer chemistry , chemistry , composite material , organic chemistry , catalysis , engineering
Modification of starch with urea was carried out at 165 °C according to solid state, paste and film techniques. With the solid state and paste techniques the extent of the reaction, expressed as % N, increased by increasing the time of treatment. Samples prepared by the film technique showed, during the first 15 min reaction time, significantly higher nitrogen content which, however, decreased by prolongation of the treatment. Infra‐red spectrum of the reaction products indicated involvement of both starch and urea in a chemical reaction. Examination of the swelling properties of the products revealed that these properties are dependent upon the technique used for preparation rather than the extent of the reaction. Samples prepared by the paste and film techniques acquired higher apparent viscosity than those prepared by the solid state technique irrespective of the rate of shear. For a given rate of shear, the apparent viscosity increases by increasing the temperature.