Prevention of moisture migration in fondant coated biscuit

Moisture migration in a newly developed product called fondant coated biscuit makes the biscuit soggy. A suitable continuous drying method was developed to make the biscuit attain the crispness of uncoated biscuits. Moisture sorption isotherms were obtained for fondant, biscuit and fondant coated biscuit separately to establish the stable moisture levels as indicated by BET and GAB equations. Drying was carried out at four different temperatures and drying data were analysed to obtain heat and mass transfer coefficients and diffusivity values from the period of constant drying rate. The diffusivity value was also obtained from the period of decreasing drying rate.