Encapsulation of ascorbic acid and bioactive compounds from acerola (Malpighia emarginata DC) pulp by spray drying and emulsion techniques using chitosan and whey protein as carriers: comparative study of the encapsulation efficiency, final product characteristics and in vitro gastrointestinal release
tropical fruits, drying, food ingredients, bioaccessibility.
Acerola (Malpighia emarginata DC) fruit has carotenoids and phenolic compounds, besides high ascorbic acid content, which is higher than most of the fruits known so far. However, several acerola bioactive compounds such as anthocyanins and ascorbic acid are easily degraded by oxygen and light, among other factors. Thus, in order to maximize the use of acerola fruits, efficient and rational technological strategies are necessary to ensure the preservation of ascorbic acid and other bioactive compounds and their use in stable food ingredients. In fact, it has been demonstrated that sensitive phytochemicals may have greater stability when encapsulated. Therefore, the use of different encapsulation techniques and the combination of drying carriers have been tested to efficiently protect different bioactive materials. In addition, another challenge for the successful development of phytochemical-rich capsules is the maintenance of their bioavailability. Consequently, it is necessary to determine the bioactive compounds stability in the gastrointestinal tract during digestion and the nutrient absorption. In this context, the objective of this doctorate project is to evaluate the encapsulation of acerola pulp by spray drying and emulsion methods, using chitosan and whey protein as carriers, either combined or alone. The comparative study will clarify the advantages and potential of each technique with respect to drying/encapsulation efficiency, the final product characteristics, as well as the release of bioactive compounds, with emphasis on ascorbic acid, in the gastrointestinal system using in vitro techniques. This research intends to develop efficient techniques for the production of acerola-based functional ingredients, a tropical fruit with great economic value and abundantly produced in Brazil.