ABSTRACT

A detailed study on the water sorption of ighu was performed. Ighu produced from cassava tubers of the Agadaba Species purchased from One Ngodo Isuochi in Umuneochi Local Government Area of Abia State Nigeria, was used for this Study. The determination of equilibrium moisture content of ighu was done using the gravimetric method. Sulphuric acid solution were used to prepare water activity values ranging from 0.10-0.90. Sorption was studied at 20°C, 30°C, 40°C and 50°C respectively. The moisture sorption isotherm data obtained was evaluated using the BET, Oswin and GAB models , while the analysis of Variance ( ANOVA) using the Duncan approach was used to determine the variance in the equilibrium moisture content (EMC) recorded from the experiment . The result of the study showed that water sorption isotherm were sigmoidal in shape typical to most food materials. Equilibrium moisture content of ighu decreased with increase in temperature (Range 11.0611 at 20°C to 6.9370 at 50°C) but increased with increase in water Activity (3.905 at water activity of 0.1 to 14.525 at water activity of 0.9 respectively. The percentage root mean square(%RMS) for the water sorption was best described by Oswin model.