کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1988239 1540318 2007 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural and thermodynamic properties of rice starches with different genetic background: Part 2. Defectiveness of different supramolecular structures in starch granules
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Structural and thermodynamic properties of rice starches with different genetic background: Part 2. Defectiveness of different supramolecular structures in starch granules
چکیده انگلیسی

High-sensitivity differential scanning microcalorimetry (HSDSC), small-angle X-ray scattering (SAXS), light (LM) and scanning electronic (SEM) microscopy techniques were used to study the defectiveness of different supramolecular structures in starches extracted from 11 Thai cultivars of rice differing in level of amylose and amylopectin defects in starch crystalline lamellae. Despite differences in chain-length distribution of amylopectin macromolecules and amylose level in starches, the invariance in the sizes of crystalline lamellae, amylopectin clusters and granules was established. The combined analysis of DSC, SAXS, LM and SEM data for native starches, as well as the comparison of the thermodynamic data for native and annealed starches, allowed to determine the structure of defects and the localization of amylose chains in crystalline and amorphous lamellae, defectiveness of lamellae, clusters and granules. It was shown that amylose “tie chains”, amylose–lipid complexes located in crystalline lamellae, defective ends of double helical chains dangling from crystallites inside amorphous lamellae (“dangling” chains), as well as amylopectin chains with DP 6–12 and 25–36 could be considered as defects. Their accumulation can lead to a formation of remnant granules. The changes observed in the structure of amylopectin chains and amylose content in starches are reflected in the interconnected alterations of structural organization on the lamellar, cluster and granule levels.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 41, Issue 5, 1 December 2007, Pages 534–547
نویسندگان
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