Fundamental aspects of controlled release in foods

The fundamental equations governing the controlled release of active ingredients and the application of controlled-release technology in food systems are reviewed in this article. The method of microencapsulation, among others, can be applied to achieved controlled release in foods. Some of the release mechanisms employed in the food industry involve one or a combination of the following stimuli: a change in tempera ture, moisture or pH; the application of pressure or shear; and the addition of surfactants. Encapsulation is a method of protecting food ingredients that are sensitive to temperature, moisture, microorganisms or other components of the food system. Such food ingredients include flavors, sweeteners, enzymes, food preservatives and antioxidants, and are encapsulated using carbohydrates, gums, lipids and/or proteins. With a properly designed controlled-release delivery system, the food ingredient is released at the desired site and time at a desired rate.