Experimental Study for Superheated Steam Drying of Apple Slice

Superheated steam drying is an advanced drying technology in the food processing field. In this study, experimental studies at different drying conditions of superheated steam drying for apple slice are presented. It is observed that the evaporation is faster at higher temperature and higher gas velocity but the effects of temperature are smoother at fast gas velocity. One empirical model is built based on Page’s model; this model enables to calculate the average moisture content versus time. The validation results show that the model yields high calculation so this can be applied to simulate the whole drying system. Product quality is also tested in terms of color change, sugar content and acid content to evaluate the application ability of superheated steam drying. Acid content and sugar content lost maximum at 130 ℃ and 140 ℃, respectively.