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An improved enzymic method for the determination of native and modified starch
Author(s) -
Karkalas John
Publication year - 1985
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740361018
Subject(s) - starch , amylose , chemistry , hydrolysis , glucose oxidase , amylase , chromatography , modified starch , waxy corn , alpha amylase , food science , phosphate , biochemistry , enzyme
Abstract An improved method for the determination of starch by sequential hydrolysis with thermostable bacterial α‐amylase and fungal amyloglucosidase is described. Glucose was determined colorimetrically by a glucose oxidase‐peroxidase‐chromogen system at pH 7. Native normal and waxy starches, and distarch phosphate, gave quantitative yields of glucose with a high degree of precision (coefficient of variation less than 1%). Acetylated distarch phosphate, high‐amylose starch and retrograded amylose were initially treated with 1M NaOH for 30 min, then neutralised and analysed successfully as normal starch. Oxidised starch did not give a quantitative yield of glucose because of the presence of dicarboxylic groups in the polymer. For samples containing normal and waxy starch the analysis was carried out in about 4 h. The method was applied to a range of starch‐containing foodstuffs and the results are reported.