Selection of Materials for Microencapsulation

Microencapsulation of food ingredients such as flavors, vitamins, minerals, essential oils, carotenoids, salts, or enzymes requires stabilization in the environment in which they are placed. Although any food-grade coating material can be conceptually used as a candidate for the microcapsule shell material, most commercial microcapsules produced to date utilize a relatively small number of different shell materials. This is because shell materials for pharmaceutical, food, and personal care products are limited to materials that are approved. Selection of microencapsulated food ingredients requires a careful balance of physical and chemical properties, shelf-life stability, processing of ingredients, and regulatory guidelines. In this chapter, the selection of the matrix material for microencapsulation is classified by the impact that it makes for a particular application. For example, using shelf stability as a criterion, materials are classified by the governing physical property to provide protection against oxygen, pressure, heat, pH, light, heavy metals, and water. Likewise, other applications such as the use of microcapsules in relation to release such as, taste masking, triggered release, color masking, color alteration, and enhanced processability are discussed.