The investigation on sorption isotherms of explosion puffing drying apple chips

Sorption isotherms were investigated for apple chips which dehydrated by explosion puffing drying at three different temperatures (25,40 and 50 ℃) and wide ranges of water activity (0.96～0.10),using standard gravimetric method.The sorption data were analyzed using five conventional models.The results show that the apple chips sorption equilibrium moisture content decreased with increasing temperature,increased with increasing water activity; the Guggenheim,Anderson and De Boer (GAB) model was found to be the best model for predicting the equilibrium moisture content of apple chips in the water activity range of 0.10～0.96 (r20.99); the monolayer moisture content decreased as temperature increased.