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Updated: Mar 31, 2026
Analysis and Specification of Starch Granule Size Distributions
Published on: March 4, 2021
Second harmonic generation microscopy investigation of the crystalline ultrastructure of three barley starch lines
Richard Cisek1, Danielle Tokarz1, Martin Steup2
1Department of Chemical and Physical Sciences, Department of Physics and Institute for Optical Sciences, University of Toronto, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada.
Abstract:
Second harmonic generation (SHG) microscopy is employed to study changes in crystalline organization due to altered gene expression and hydration in barley starch granules. SHG intensity and susceptibility ratio values (R'SHG ) are obtained using reduced Stokes-Mueller polarimetric microscopy. The maximum R'SHG values occur at moderate moisture indicating the narrowest orientation distribution of nonlinear dipoles from the cylindrical axis of glucan helices. The maximum SHG intensity occurs at the highest moisture and amylopectin content. These results support the hypothesis that SHG is caused by ordered hydrogen and hydroxyl bond networks which increase with hydration of starch granules.
