Storage Stability Study of Tacca Starch at different Temperatures

Abstract

The knowledge of water sorption Isotherm gives information about water activity of foods. This study therefore was to determine the best model for tacca starch at three different temperatures (20, 30 and 40 °C) and the best temperature at which tacca starch can be kept. Three temperatures were used for this study to determine the best region to store tacca starch either at temperate or tropics areas. Adsorption characteristics of tacca starch were determined at 20, 30 and 40 °C temperature using the static gravimetric procedure. Samples were equilibrated in desiccators containing tetraoxosulphate (VI) solution of known water activity (0.1-0.8). The
appropriate constants in the sorption equation were determined by excel slover at temperature. The data obtained were fitted to seven moisture sorption models, GAB, Oswin, modified Oswin, BET, Hasley, Smith and Henderson models. The coefficients of determination varied from 0.7654 - 0.9999.Both GAB and Oswin models gave the most suitable models for describing the sorption data among the temperatures studied. A comparison of the EMC curves showed that at temperature 40 °C the tacca starch had lower equilibrium moisture contents and GAB model was found suitable for predicting tacca starch, hence tacca starch is favorable for storage in the tropical regions.