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Anisotropic scattering by single starch granules. II. Layered granule structure
Author(s) -
Finkelstein R. S.,
Sarko A.
Publication year - 1972
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1972.360110411
Subject(s) - anisotropy , granule (geology) , layering , scattering , starch , chemistry , isotropy , light scattering , crystallography , mineralogy , optics , materials science , composite material , botany , physics , food science , biology
The study of anisotropy light scattering from tapioca and potato starches has continued with the recording of more detailed experimental single‐granule H v scattering patterns and, for the first time, single‐granule V v patterns. Quantitative analysis of the higher order scattering maxima to the granule morphology, permitting an analysis of the latter in terms of a lyered structure. For tapioca starch, this analysis indicates that if layering is present at all, the layer thickness is comparable to the wavelength of the incident radiation, and most likely is considerably less than 0.5 μ in thickness. On the other hand, the potato starch morphology is characterized by a relatively coarse layering with few layers and considerable difference in the anisotropy between successive layers. The models for the two starches in best agreement with experimental data are as follows: almost perfectly spherulitic anisotropic structure with very thin shell‐like layers—if any—for tapioca, and alternating layers of varying anisotropy several microns in thickness and probably simultaneously present with an isotropic center, for potato starch. The V v pattern for tapioca starch is in agreement with this model, although its information content is lower owing to the experimental difficulty of recording higher order maxima. Suggestions for further morphological study of starches are presented.