title: Causal relations between structural features of amylopectin, a semicrystalline hyperbranched polymer.
abstract: The relationships were determined between molecular properties of amylopectin, a hyperbranched glucose polymer and the major component of starch, and higher-level structures in native starch (double helices, crystallinity and crystalline-amorphous lamellae). Parameters from NMR, differential scanning calorimetry, and size exclusion chromatography of β-limit dextrins of a series of waxy starches, together with literature data, gave information on relationships between the structure of the interior of the amylopectin molecule and crystallinity. The structure of internal B chains (those with one or more branches) of amylopectin influences both crystalline properties and crystallinity. More B chains produce larger crystalline-amorphous lamellae, probably by expanding the amorphous lamellae, while larger B chains increase the ability of annealing to increase order through greater mobility for the chains to rearrange at higher temperatures. This study brings into question the common assumption that A chains (unbranched chains) are necessarily smaller than B chains.
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology , Wuhan, China , 430030.
authors: Torsten
authors: T
authors: Witt
authors: Robert G
authors: RG
authors: Gilbert
mesh_terms: D000687:Amylopectin / Q000737:chemistry*; D000688:Amylose / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D005936:Glucans; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D013213:Starch / Q000737:chemistry; D001614:beta-Amylase / Q000737:chemistry
chemical_list: D005936:Glucans; D011108:Polymers; D013213:Starch; D000688:Amylose; D000687:Amylopectin; D001614:beta-Amylase