Year: 1948
Type: article
Abstract: The fractionation of starch by precipitation with butanol and similar alcohols, first developed by Schoch (1942), stimulated research in this field by providing the first efficient method of preparing in reasonably pure form the components, amylose and amylopectin.These names have often been applied to the corresponding fractions obtained by earlier methods in various degrees of purity, and in con- sequence are associated in the literature with many conflicting statements.They are nevertheless re- tained here, it being understood that amylose, con- sisting essentially, ifnot solely, ofunbranched chains of oc-glucopyranose units, is the fraction precipitated from starch paste by butanol, amylopectin re- maining in dispersion.It is supposed that amylose is completely hydro- lyzed to maltose by fi-amylase, although the evidence for this is not entirely satisfactory, since pure sub- strate and enzyme have rarely, if ever, been em- ployed in the same experiment.Tests of the purity of starch fractions include the limit of /3-amylase action, analysis of iodine coloration and potentiometric titration with iodine; the first two have been extensively employed in this work.In the present investigation, attempts have been made to obtain pure amylose and amylopectin by the known pre- cipitation methods, and if possible to improve upon
Source: Biochemical Journal
DOI: 10.1042/bj0430028
Authors: R. H. Hopkins, B. Jelinek
Institution: University of Birmingham
Language: English
Subfield: Nutrition and Dietetics
Field: Nursing
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W38243781