Insights into structure-function relationships of starch from foxtail millet cultivars grown in China

Structure-function relationships of starch isolated from eight cultivars of foxtail millets grown in China were investigated. The starch granules were polygonal with diameters between 5 μm and 10 μm. The amylose content ranged from 16.8% to 26.8%, and the relative crystallinity and the full width at half maximum (FWHM) of the Raman band at 480 cm^-1 varying between 33.2% and 36.4% and 15.72 to 15.91, respectively. There were only small differences in amylopectin chain length distribution of the eight foxtail millet starches. Significant differences were noted in swelling power, gelatinization, pasting, gel textural properties of starches, but not in vitro enzymic digestibility. Correlation analysis results showed that amylose content and chain length distribution of amylopectin were more important determinants of functional properties of starch than the structural order of the starch granules.