A high amylose starch isolated from the tubers of Curcuma aeruginosa

摘要

NMR spectra of the starch,isolated from Curcuma aeruginosa in dimethyl sulphoxide-d_6 contain groups of minor ~(13)C,~1H,or O~1H signals attributable to glycosyl end groups and the absence of other residues associated with branching in amylopectin molecules.The relative intensities of these signals are evaluated in terms of the incidence of end groups,or branches in the starches.The alpha configuration of the glucan has been confirmed by treatment with alpha amylase,and also by its high [alpha]_D~(20) value of +118.9.13.~(13)C NMR and ~1H NMR spectral studies show that it is a high amylose starch.X-ray diffraction study reveals B-type polymorphic forms characteristic of high amylose starch.They are also compared with spectrophotometric measurements on the iodine complexing capacity of starches.