Supermolecular structures of recrystallized starches with amylopectin side chains modified by amylosucrase to different chain lengths [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 642.8 Table decorations
• Thông tin xuất bản: Oak Ridge, Tenn. : Oak Ridge, Tenn. : Oak Ridge National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2021
• Mô tả vật lý: Size: Article No. 106830 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 259702
• Chủ đề: 1. 60 applied life sciences; 2. Amylosucrase; 3. Lamellar structure; 4. Nanocrystals; 5. Saxs; 6. Starch

Tóm tắt

Understanding the supermolecular structures of recrystallized starches is imperative to manufacture novel starches with controllable physicochemical properties enabling novel applications. In this study, native amylopectin (AP) from maize was modified to different chain lengths using amylosucrase from Neisseria polysaccharea. Native AP granules showed well-organized lamellar structures with a periodicity of ca. 9.0 nm whereas modified starches formed heterogeneous structures with the average crystallite size ranging from 19.77 to 29.88 nm. Acidic treatments eroded amorphous domains in both native AP granules and modified starch particles, producing nanocrystals composed of double helices. A-type nanocrystals (~40 nm) from native AP granules showed quadrangular shape with an acute angle of ca. 60�, while irregular B-type nanocrystals were observed for the modified starches. Molecular characterizations suggested that the nanocrystals had relatively uniform chain lengths (DP 16.5?25.2), and the helix length (the thickness of nanocrystals) was positively correlated to the thermal stability of starches.