The new insight on ultrastructure of C-type starch granules revealed by acid hydrolysis.
C-type starch granule could be considered as the mixture of A- and B-polymorphs. The ultrastructure of C-type starch granules has not been elucidated detailedly by comparison with that of A- or B-type starch. To better understand the ultrastructure of C-type starch granules, Environment Scanning Electron Microscope (ESEM) and Field Emission Gun Transmission Electron Microscope (FEG-TEM) have been used to analyze the conformation and ultrastructure of C-type starch granule from Rhizoma Dioscorea during acid hydrolysis. SEM results showed that the amorphous areas were mainly located interior part of C-type starch granules whereas the crystalline regions were found mostly in the peripheral region of the granules. The grain size can be confirmed to be about 4.5-9 nm from the HR-TEM micrographs. The nanocrystals from acid-thinned starch displayed the typical face-centered cubic structure. This selected area electron diffraction patterns showed that individual C-type starch granule consisted of A- and B-type polymorphs.
Wang
Shujun
S
School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China.
Yu
Jinglin
J
Jin
Fengmin
F
Yu
Jiugao
J
D008854:Microscopy, Electron; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D013213:Starch / Q000737:chemistry / Q000648:ultrastructure*
D013213:Starch