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Methods of Starch Analysis
Author(s) -
Mitchell Gordon A.
Publication year - 1990
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19900420403
Subject(s) - starch , hydrolysis , chemistry , dissolution , optical rotation , acid hydrolysis , enzymatic hydrolysis , syneresis , chromatography , organic chemistry
The Ewers method, based on the partial acid hydrolysis of starch, followed by measurement of the optical rotation of the resulting solution, is an official E. C. method and used for determination of starch purity (regulation 2169/86). Short reviews of the evolution of this method, the method based on calcium chloride dissolution followed by optical rotation measurement, and enzymatic methods, have been made. Several of the key parameters of the acid hydrolysis method have been examined, namely solution clarity, clarifier level, degree of hydrolysis, and evolution of optical rotation with time. Results confirm that starches from different plant origins do not behave similarly during acid hydrolysis. The present factors for the respective starches may need some minor refinement. Application of both polarimetric methods and the AFNOR enzymatic method to four different starch types, give mostly acceptable results. For ease of use, the calcium chloride method has advantages over its acid hydrolysis counterpart.