Isolation, Modification and Characterization of Tiger-Nut, Maize, Cassava and Potato Starch

Abstract

Four different sources of starchy foods were used for the isolation of starch using commercially cheap and readily available chemical-hypo (3.5 % active Chlorine). The isolated starch was modified through NaIO₄ oxidation under mild reaction conditions. Carbonyl functional group test was employed for confirmation of the success of oxidation. FT-IR and Scanning Electron Microscopy (SEM) were used for functional group identification and morphological examination of both modified and native samples to further confirm the success of modification. The appearance of the carbonyl band at 1747-1746 cm^-1 and 1647 – 1637 cm^-1 indicated the successful synthesis of oxidized starch. Proximate results showed that the isolated starches were rich in mineral content: 0.25-2.13; crude fibre: 0.85-3.31; fat: 0.23-0.28 and energy: 1331-1410. The study showed that commercial hypo could be a useful replacement for metabisulphite for starch isolation without side effects on starch properties. SEM images showed that morphological architecture of granules was not destroyed during surface functionalization. Characteristic and nutritional features of the oxidized starch showed that it could find useful applications in food and pharmaceutical industries.