The modified Chung-Pfost equation was found to be a good model for moisture adsorption and desorption of yoghurt
powder spray. According to Kumar and both Oswin and GAB models were acceptable in describing equilibrium moisture content–equilibrium relative humidity (EMC–ERH) relationships for yogurt powder samples over the range of temperatures from 20 to 50 °C. According to Peleg model fits best the isotherms of instant tea and green tea granules.