Chemically speaking, dishes are mainly composed of water, proteins and amino acids, lipids and saccharides, but they also contain many compounds that are minor in terms of proportions but can be important in terms of sensory appreciation, nutrition or toxicology. The diverse nature of “food matrix” demands a classification of them at different physical scales. The “dispersed system formalism” (DSF) provides such a description. During mastication, solid and soft food matrices become reduced in size to an extent depending on their physical properties and the chewing behaviour of individuals. Emulsions are described by DSF formulas such as oil-in-water, as in mayonnaise, water in oil or even water in water in some particular Ramsden solutions. Several foods are porous materials consisting of a continuous matrix, which may be a solid or a gel, enclosing open or closed gas cells. Porous matrices may be formed by fermentation and baking, extrusion, aeration or gasification, gas release from chemical reactions, or freeze-drying.