The Effect of Some Extraction Solvents on the Chemical Structure of the Starches from tobacco Leaf and Potato Tubers

Abstract

Tobacco leaf starch was isolated as granules by mechanical extraction, and the viscosity, amylose content, B-amylolysis limit, starch-iodine complex absorption spectrum, and apparent chain length compared with samples extracted by perchloric acid, sodium hydroxide, and chloral solution and purified as the starch-iodine complex. The efficiency of extraction of these methods was also compared. The same comparisons were made with potato granules and potato granules treated with these extracting reagents. Evidence is presented that the most efficient method of extraction of tobacco leaf starch is with perchloric acid but all solvent extraction methods give a degraded starch with low viscosity. The B-amylolysis limits are similar, while the starch-iodine absorption spectra and apparent amylose contents of the extracted starches and granules may differ slightly, but solvent-extracted starches show a quite different pattern of acid release on oxidation with periodate ion which makes estimation of apparent chain length difficult.