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Suitability of Starch Granule Porosity for Biosynthesis and Amylolysis Susceptibility
Author(s) -
Planchot Véronique,
Roger Philippe,
Colonna Paul
Publication year - 2000
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 - 10.1002/1521-379x(200010)52:10<333::aid-star333>3.0.co;2-9
Subject(s) - size exclusion chromatography , chemistry , molar mass , starch , molecular mass , chromatography , granule (geology) , elution , porosity , potato starch , degree of polymerization , polymerization , polyethylene glycol , polyethylene , hydrodynamic radius , volume (thermodynamics) , organic chemistry , polymer , materials science , thermodynamics , composite material , physics , copolymer , enzyme
A packed column procedure was used to estimate the pore volume of native starch granules from seven different botanical sources. Polyethylene glycols (PEG) were employed as probes after determination of their hydrodynamic radius by quasi‐elastic light scattering. The gel phase of native starch granules is penetrable by low‐molar‐mass solutes such as maltooligosaccharides (MOS) or small PEG. Molecules with a degree of polymerization greater than 6—7 were excluded. This size threshold corresponds to carbohydrates with a molar mass of 1,000 g/mol or proteins with a hydrodynamic radius of 0.6 nm. Two‐stage curves were observed for all starches studied. Molecular probes had a diameter of less than 0.6—0.8 nm in the first part and larger diameters in the second part of the curves. The mechanism of size‐exclusion‐chromatography was followed in the first part, the phenomenon of hydrodynamic chromatography was applicable in the second. Regardless of the starch studied, MOS displayed similar behavior, characterized by a higher elution volume than expected from their molecular size.