Shelf-life modelling of moisture sensitive food products

The water vapour sorption isotherms of different types of "starch-based dried products" were determined at 25°C and the experimental data were fitted through available sorption equations. The validity of fit was evaluated by means of the mean relative deviation modules and the equation with the best fit was selected. The sorption isotherm equation, the permeability values of the packages and others product characteristics were used together in a mathematical model to predict the moisture gain by packaged biscuits and crackers. Good agreement was found between the experimental data obtained from actual storage testing of the same products and those predicted by the model.