Indian Journal of Science and Technology

Abstract

Objectives: To isolate and modify starch using new and non-commonly used commercially available, cost-effective reagents and study the changes in functionality and physicochemical properties. Methods/Statistical Analysis: An outline and modification of the method: Addition of 100 mL of a 500 mL solution of 3.5 % hypochlorite (household bleach commonly known as hypo) in 2 L of water at interval of 1 min during grinding. Hypo substituted sodium metabisulphite, prevented browning and enhanced rasping and acted as bleach. Mucilage obtained by the modified method was nonsticky to starch cake. FT-IR results confirmed the direct formation of oxidized starch. Findings: Acetyl content (0.01-0.89 %) and DS (0.011-0.2) obtained by the modified method was in agreement with the approved DS by the Food and Drug Administration for food use. Proximate results showed that the isolated starch was rich in mineral content, fibre, fat and energy. Thermoplasticity of high temperature mercerized starch was revealed by SEM images. These properties will influence their use in composites and other applications where strength needs to be improved as documented. Mercerized starches as flocculants in water cleaning as ion changers or retention agents in the paper industry. The C=O absorption bands were observed at 1634, 1650, 1647 and 1646 cm-1 for mercerized starch. Bands observed at 1640, 1641, 1640, 1640 and 1642 cm-1 and 2932, 2926, 2920 and 2929 cm-1 and 1358, 1389, and 1385 cm-1 are assigned CO, C-H of methylene and -CH2 stretching vibrations in ester group due to acetylation. Results of these findings showed the application of hypo and vinegar for isolation and acetylation of starch respectively. Application/Improvements: The feasibility of the modified method for starch isolation and modification using readily available, cost effective and eco-friendly chemicals for obtainment of food and pharmaceutical grade starch.

Keywords: Characterization, Modification, Potato, Starch, FT-IR, SEM