Behaviour of Oxidized Starches Towards Cyanoethylation
作者:
I. Abd El‐Thalouth,
A. Ragheb,
R. Refai,
A. Hebeish,
期刊:
Starch ‐ Stärke
(WILEY Available online 1990)
卷期:
Volume 42,
issue 1
页码: 18-23
ISSN:0038-9056
年代: 1990
DOI:10.1002/star.19900420107
出版商: WILEY‐VCH Verlag GmbH
数据来源: WILEY
摘要:
AbstractStarch of different molecular sizes brought about by oxidation of maize and rice starches were cyanoethylated under identical conditions. The degree of cyanoethylation, expressed as % N, was found to depend mainly on the molecular size of starch irrespective of its kind. As the molecular size decreases the degree of cyanoethylation increases. Cyanoethyl starches are water soluble and can be precipitated by ethanol. It was also found that the rheological properties are determined by the nitrogen content of cyanoethyl starch. When the latter acquires low nitrogen content, it exhibits non‐Newtonianpseudoplastic behaviour. On the other hand, cyanoethyl starches with higher nitrogen content are characterized by non‐Newtonianthixotropic. At constant rate of shear, the apparent viscosity of cyanoethyl starches is directly related to its molecular size. Storing of pastes prepared from these cyanoethyl starches for 7 d exerts considerable influence on rheological properties and apparent viscosity of these derivati
点击下载:
PDF
(555KB)
返 回