Barley-Pearl Millet-Milk based Mineral Fortified Complementary Food: Moisture Adsorption Isotherms

Abstract

The equilibrium moisture contents (EMC) of complementary food were determined using the static gravimetric method at 28, 37 and 45 °C in the water activity (a_w) range of 0.11-0.92. The adsorption isotherms obtained were of sigmoid shape resembles type II according to BET classification. EMC at a given (a_w) decreased as the temperature increased and inversion point obtained at 37 °C at higher water activity. BET and GAB models described the EMC/a_w relationship by giving a closest fit to the experimental sorption data. The suitability of the models was determined by multiple statistical criterion viz. the coefficient of determination (R²), mean relative per cent deviation modulus (P), Root Mean Square Deviation error (RMS %) and Chi-square (c²). The monolayer moisture content obtained by BET and GAB models are concur.