Modification of starch granules by hydrolysis with hydrochloric acid in various alcohols, and the formation of new kinds of limit dextrins
✍ Scribed by Jeffrey D. Fox; John F. Robyt
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 403 KB
- Volume
- 227
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
Potato starch was treated severally ili methanol, ethanol, 2-propanol, and 1-butanol with 0.36% and 6.0% HCl at 25". The average d.p. dropped rapidly for starch treated with 0.36% acid and reached a limiting value within 24 h. For the treatment with 6.0% acid, the limiting value was reached between 30 and 75 h. The limiting d.p. progressively decreased in the sequence methanol > ethanol > 2-propanol > 1 -butanol, and also decreased with an increase in the concentration of the acid. The amylose and the amylopectin fractions were isolated from the modified starches, and their average d.p. and proportions were determined. The amylopectin fractions were analyzed by gel-permeation chromatography on Bio-Gel A-5m, before and after isoamylolysis, and the amylose fractions were analyzed on Bio-Gel A-0.5m. The above starch products represent a new type of limit dextrins that have different average d.p., chain-length distributions, and proportions of amylose and amylopectin. These differences represent variable susceptibilities of the glycosidic bonds to hydrolysis when the starch granules are placed in different alcohols with different concentrations of acid.