A high amylose starch isolated from the tubers of <i style="">Curcuma aeruginosa</i>

Abstract

NMR spectra of the starch, isolated from <i style="">Curcuma aeruginosa</i> in dimethyl sulphoxide-d_6,contain groups of minor ¹³C, ¹H, or O¹H 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 <img src='/image/spc_char/alpha.gif' border=0> configuration of the glucan has been confirmed by treatment with a amylase, and also by its high [<img src='/image/spc_char/alpha.gif' border=0>]_D²⁰value of +118.9.13. ¹³C 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.