title: Crystallite orientation maps in starch granules from polarized Raman spectroscopy (PRS) data.
abstract: In this work, polarized Raman spectroscopy (PRS) was used to determine orientation maps of crystallites present in Phajus grandifolius starch granules based on the anisotropic response of the glycosidic Raman band at 865cm(-1). The response of this band was preliminarily evaluated using model A-amylose crystals as standard. The A-amylose crystals oriented "in plane" showed a maximal intensity ratio of ∼3.0 for bands 865/1343cm(-1) when the polarization of the laser was along the chain axis of the crystal, i.e., parallel to the axis of the amylose double helices, and a minimal intensity ratio of ∼0.25 when perpendicular. The orientation maps of Phajus grandifolius starch granules showed two distinct regions: one isotropic and the other with a highly anisotropic response. The origin of the difference might be changes in both organization/concentration and orientation of the crystallites across the starch granules.
authors: Aalto University, School of Chemical Technology, P.O. Box 16300, 00076 Espoo, Finland.
authors: Leonardo
authors: L
authors: Galvis
authors: Aalto University, School of Chemical Technology, P.O. Box 16300, 00076 Espoo, Finland. Electronic address: carlo.bertinetto@aalto.fi.
authors: Carlo G
authors: CG
authors: Bertinetto
authors: Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000 Grenoble, France; CNRS, CERMAV, F-38000 Grenoble, France.
authors: Jean-Luc
authors: JL
authors: Putaux
authors: Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000 Grenoble, France; CNRS, CERMAV, F-38000 Grenoble, France.
authors: Nicole
authors: N
authors: Montesanti
authors: Aalto University, School of Chemical Technology, P.O. Box 16300, 00076 Espoo, Finland.
authors: Tapani
authors: T
authors: Vuorinen
mesh_terms: D000688:Amylose / Q000737:chemistry; D016880:Anisotropy; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D029595:Orchidaceae / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013213:Starch / Q000737:chemistry*
chemical_list: D013213:Starch; D000688:Amylose
keywords: Amylopectin (PubChem CID: 439207); Amylose (PubChem CID: 53477771); Amylose single crystals; Polarized Raman spectroscopy; Starch granules