November
2004
Volume
81
Number
6
Pages
735
—
740
Authors
Yixiang
Xu
,
2
Vesselin
Miladinov
,
3
and
Milford A.
Hanna
2
,
4
Affiliations
Journal Series No. 14421, Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln. This study was conducted at the Industrial Agricultural Products Center, University of Nebraska, Lincoln, NE.
Industrial Agricultural Products Center and Department of Food Science & Technology, University of Nebraska, Lincoln, NE 68583-0730.
Cadbury Adams, Morristown, NJ 07960.
Corresponding author. Phone: +1-402-472-1634. Fax: +1-402-472-6338. E-mail: mhanna1@unl.edu
Go to Article:
RelatedArticle
Accepted March 9, 2004.
Abstract
ABSTRACT
Acetylation of high-amylose (70%) maize starch to high degree of substitution (DS) was studied by reacting starch with acetic anhydride using 50% aqueous NaOH as the catalyst. DS increased with increasing reaction times and increasing ratios of acetic anhydride to starch. Reaction efficiency (RE) increased with longer reaction times and decreased with increases in the ratios of acetic anhydride to starch for extended reaction times. Increasing the amount of NaOH increased both DS and RE. A series of starch acetates with DS values of 0.57–2.23 were prepared and their crystalline structures, chemical structures, thermal stability, and morphological properties were investigated. After acetylation, and as DS increased from 0.57 to 2.23, the crystalline structures of starch steadily disappeared. The carbonyl group's peak at 1,740 cm-1 appeared in the FTIR spectra. The intensity of this peak increased with a decrease in the peak intensity of the hydroxyl groups at 3,000-3,600 cm-1, indicating that the hydroxyl groups on starch were replaced by the acetyl groups. Thermal stability of starch acetates increased. The smooth surface of the starch granules became rough with acetylation. Further acetylation led to the loss of the starch granules and the formation of beehive- and fibrous-like structures.
JnArticleKeywords
ArticleCopyright
© 2004 American Association of Cereal Chemists, Inc.