Abstract

An overview is given of flavor delivery systems and technologies for flavor encapsulation. A central conceptual distinction made is between systems aimed at protecting the encapsulated flavor against evaporation and the adverse effects of environmental oxygen in low-moisture states, and those whose principal aim is to modify the release of the encapsulated flavor during food processing, storage, or consumption. The former class of systems, which are designated as glass-encapsulation systems since they are invariably based on amorphous carbohydrates in the glassy state, are generally prepared by well-established technologies like spray drying and melt extrusion. These systems have found widespread commercial application. Accounts are given of the most-used technologies and of the underlying material science. The latter class of systems, principally aimed at controlling the release rate of the encapsulated flavor, is far more diverse in composition, working principle, and manufacturing technology. Their common feature is that, in the food matrix, they retain a core structure whose role is to control both the rate and the extent of release of the encapsulated flavor. It is argued that application of such systems necessitates a careful tuning of the delivery system to both the specific composition of the flavor, the composition and structure of the food matrix and the conditions during food processing, storage and consumption, because of the comparatively well-defined release aimed for. Several of the principal technologies are highlighted. Examples are given of successful applications in food matrices. It is conjectured that limitations currently experienced in the application of controlled release systems for flavors and that impede a truly widespread adoption in the food industry can only be eliminated by a concerted approach including encapsulation technology, flavor physico-chemistry and chemistry, food materials science, and focused product development efforts.