Encapsulation of functional components is commonly used to protect them from the environment, or to control their release. In the present study, iron is used as a model nutrient that is encapsulated in water-in-oil emulsion. Fat based emulsion particles are produced using that emulsion through prilling process using twin fluid atomizers. The particles are characterized in terms of size and size distribution, and their internal structure is investigated by cryogenic scanning electron microscopy (cryo-SEM). The iron release kinetics through the fat matrix of the emulsion particles in an in vitro gastric system (pH approximate to 2.0) is described by the second order kinetics. An empirical correlation of the release kinetics rate constant is proposed as a function of the viscosity ratio of dispersed to continuous phase, mean particle size, and shelf-life of the particles. It is seen that the release kinetics can be controlled by choosing particle size and thickener concentration. (C) 2012 Elsevier Ltd. All rights reserved.