ISOLATION AND PHYSICOCHEMICAL CHARACTERIZATION OF STARCH FROM TARO BOLOSO-I TUBERS

Abstract

Taro Boloso-I is a new variety of Colocasia esculenta (L. Schott) officially released from Areka Agricultural Research Center, Areka, Ethiopia. Its cultivation out yields a previously reported variety (Godare) by 67%. The study focuses on isolation and characterization of starch from this plant. Isolation of starch was done using saline and sodium hydroxide and characterized for its physicochemical constituents. Its yield on dry weight basis was 83.5 ± 1.6%. The native Taro Boloso-I starch (NTBIS) showed lower amylose to amylopectin ratio (20.7 ± 1.8% to 77.3 ± 2.1%, w/w) and significantly higher onset (68.40˚C), peak (75.46 ˚C) and endset (84.40 ˚C) temperatures of gelatinization than potato starch which has gelatinization range of 62.50–67.53–79.40 ˚C. The shapes of the granules were polyhedral/angular with an A-type polymorphism with a poor flow.The starch is comprised of small particles (mean diameter of 2.45 ± 0.11 μm).Taro Boloso-I starch possesses similarity with cereal starches like the rice starch though it is a tuber starch and moreover, on comparison with the previously reported varieties of Taro, there is difference in its properties.