Rapid quantification of starch molecular order through multivariate modelling of¹³C CP/MAS NMR spectra

Abstract

A partial least squares model has been generated enabling the rapid assessment of ordered molecular structure in a semi-crystalline polymer, starch, directly from solid state NMR spectra. Solid state NMR spectroscopy offers many advantages over conventional analysis tools being non-destructive and functional in complex mixtures.

Effects of sorbitol and formamide plasticizers on molecular motion in corn starch studied using NMR and DMTA

“…The CP MAS 13 C NMR spectrum of native starch depicted in Figure shows the shape characteristic for semicrystalline starch. Three peaks at positions 101.6, 100.5, and 99.5 ppm in the C 1 resonance, typical for double helices packed in a monoclinic lattice (A‐type structure), were observed in this spectrum . The triplet corresponds to the three equivalent classes of six monomers creating the single helical turn, and is related to three distinct torsions about the α—(1‐4) linkage .…”

“…The 13 C CP MAS NMR spectra measured for native starch and plasticized F‐TPS and S‐TPS samples depicted in Figure show four clearly resolved resonance lines associated with the six carbon nuclei in the starch monomer unit at ~101 ppm (C 1 ), ~83 ppm (C 4 ), ~73 ppm (C 2,3,5 ), and ~62 ppm (C 6 ) . One more resonance at the chemical shift of 167 ppm was observed in the spectrum of F‐TPS, which is associated with formamide carbon nuclei .…”

“…There are three different types of crystalline phase: A (monoclinic), B (hexagonal), and C (combination of A and B types), depending on the space arrangement of amylopectin double helices and water molecules . Particular polymorphs can be identified using X‐ray diffraction and/or nuclear magnetic resonance ( 13 C NMR) measurements …”

Microstructural Changes and In Vitro Digestibility of Maize Starch Treated with Different Calcium Compounds Used in Nixtamalization Processes

“…The intensity peaks can be linked to the carbon positions of the glycosidic ring. Flanagan et al [20] found that the intensity peak C2, 3, 5 is asymmetric for native (i.e., semi-crystalline) starch, while approaches a symmetric shape for amorphous samples. Gaussian function-based deconvolution was carried out to quantify the asymmetry of this peak.…”

A further study on supramolecular structure changes of waxy maize starch subjected to alkaline treatment by extended-q small-angle neutron scattering

“…There are two starch polymers biosynthesised during plant growth, namely amylose and amylopectin (Liu, Halley, & Gilbert, 2010;Jiang, Gao, Li, & Zhang, 2011). These two polymers can be organized on different scales in the starch granule to construct a multiscale supramolecular system; this system involves the whole granule, growth rings, blocklets, semicrystalline lamellae, crystallites, and double/single helices (Buleon, Colonna, Planchot, & Ball, 1998;Luengwilai & Beckles, 2009;Perez & Bertoft, 2010;Blazek & Gilbert, 2011;Doutch & Gilbert, 2013;Flanagan, Gidley, & Warren, 2015;Zhang et al, 2015). The structures with scales larger than that of lamellae can be loosely termed as 'large-scale' structures, including the growth rings and blocklets (Doutch et al, 2013).…”