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Chemical Structure of Barley Starches. I. A Study of the Properties of the Amylose and Amylopectin from Barley Starches Showing a wide Variation in Brabender Cooking Viscosity Curves
Author(s) -
Dehaas Bernice W.,
Goering K. J.
Publication year - 1972
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.19720240502
Subject(s) - amylopectin , amylose , chemistry , food science , starch , viscosity , limiting , polysaccharide , chromatography , thermodynamics , organic chemistry , physics , mechanical engineering , engineering
The starches from two barley varieties showing extreme differences in cooking viscosity were fractionated. The amylose and amylopectin from the variety showing a high cooking viscosity, Nupana, are larger than those from the low cooking viscosity variety, Titan. Although no substantial differences were observed in the yields and chain length in the debranched amylopectins, there is evidence that the Titan amylopectin branches contain a block to β‐amylase action. This would account for the low beta‐limit on the Titan amylopectin. The breaking of H‐bonding on heating should allow the starch fractions more freedom to expand and accounts for the fact that the starch having the largest fractions exhibits the greatest viscosity. The molecular size of amylose as estimated by the use of the polarograph suggests that the use of limiting viscosity for this purpose should be used with caution.