| Autor: |
Baldwin, P.M., Adler, J., Davies, M.C., Melia, C.D. |
| Zdroj: |
Journal of Cereal Science; May 1998, Vol. 27 Issue: 3 p255-265, 11p |
| Abstrakt: |
High resolution imaging of the surfaces of starch granules from two different botanical sources has been performed using two complementary techniques: low voltage scanning electron microscopy (LVSEM) and atomic force microscopy (AFM). LVSEM provided superior images ofuncoatedgranules than possible by conventional scanning electron microscopy, and these images were used to validate the features revealed at higher resolution by AFM. The AFM images demonstrated that, although intra-sample variation exists, the surfaces of wheat and potato starch granules possess substantially different topographies. Potato starch had many protrusions (50–300 nm in diameter), above a flatter surface, which contained structures in the order of 10–50 nm. Wheat starch had far fewer protrusions and generally had a smoother surface made up of 10–50 nm structures. The 10 to 300 nm structures are believed to be carbohydrate in nature and correspond to ‘blocklet’ structures, comprising groups of amylopectin side-chain clusters presenting at the granule surface. We conclude therefore that near-molecular resolution topography of the starch granule surface has been revealed, which has allowed further insight into starch granule structure and molecular organisation. |
| Databáze: |
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