Encapsulation of Polyphenols - Techniques and Applications in Food Products

Over the past decades, polyphenolic compounds have received a lot of attention in both the scientific community and the food industry. The potential health benefits make these compounds interesting for food fortification. However, due to low stability and unpleasant taste at higher concentrations, the use of polyphenols in food products is limited. Encapsulation, a process based on forming a physical barrier around an active substance, is a promising way of overcoming these problems. The number of research studies and reviews focusing on polyphenol encapsulation is on the constant rise. Polyphenol encapsulates tend to display greater stability during processing and storage compared to non-encapsulated polyphenols and, therefore, have a high potential for application in foods. However, papers focusing on the practical application of encapsulated polyphenols are scarce. For that reason, the aim of this work was to present possible applications of such encapsulates in foods, as well as to summarize the most popular techniques used for this purpose. Encapsulated polyphenols can be applied as functional food ingredients and/or food colorants in various products, such as milk products, bakery products, and confectionery. The most commonly employed techniques for polyphenol encapsulation include spray drying and freeze-drying, as well as ionic gelation, complex coacervation, and liposome entrapment. In terms of limitations, the increased cost of industrial production and the low bioavailability of polyphenols and their encapsulates should be further investigated.