PHYSICOCHEMICAL STUDIES OF STARCH FROM FOXTAIL MILLET (SETARIA-ITALICA BEAUV)

Properties of starch granules prepared from 53 varieties of foxtail mi llet were examined by scanning electron microscopy, amperometric iodin e titrimetry and differential scanning calorimetry. The granular size of the starches ranged from 6.8 to 11.8 mu m in diameter on average. T he wavelength at maximum absorption (lambda(max)) for iodine-starch co mplexes ranged from 579 to 600 nm and blue values (absorbance at 680 n m, BV) ranged from 0.350 to 0.495 except for two waxy varieties. Amylo se contents of non-waxy varieties obtained by amperometric titrimetry ranged from 11.4 to 27.1%. DSC analysis for starch gelatinization indi cated that peak temperatures (T-p) of all the samples ranged from 62.5 to 75.1 degrees C, their enthalpy (Lambda H) varied from 8.2 to 13.5 J/g, respectively, and that there was a positive relationship between T-p and Lambda H. From a correlation matrix of physicochemical paramet ers of the millet starch, we observed the following: correlations betw een particle size and four parameters (enzymic degradation of starch g ranules, amylose content, lambda(max) and BV), between amylose content and two parameters (lambda(max) and BV), and between Lambda H and thr ee parameters (amylose content, BV and T-p).