A SIMPLE AND RAPID COLORIMETRIC METHOD FOR THE DETERMINATION OF AMYLOSE IN STARCH PRODUCTS

A method for the determination of the amylose content in starch has be en developed which is based on the colorimetric measurement of the iod ine complexes formed with amylose and amylopectin. The method requires measurement at only one wavelength and avoids the use of harsh disper sants for the starch. Dimethyl sulphoxide is used as the dispersant an d a wavelength of 600 nm can be used for measurement of the amylose co ntent of starches from different botanical sources. A linear relations hip was obtained between absorbance and amylose concentration for mixt ures of amylose and amylopectin standards, and this forms the basis of the determination. The method is rapid, simple, accurate and does not require the use of multi-component analysis of spectra, since a wavel ength is chosen that suits the particular starch being analysed. It ca n be adapted to a micro-scale method if necessary.