Modelling of water vapour adsorption on foods products by a statistical physics treatment using the grand canonical ensemble

► New model was established by statistical physics to fit water isotherm in food. ► The model is able to predict the topography of the adsorbed molecules on the food. ► Monolayer adsorbed quantity gives the capacity of the surface to retain water. ► We calculate the adsorption energy which depend on the chemical composition of food.