Development of alginate beads with encapsulated jabuticaba peel and propolis extracts to achieve a new natural colorant antioxidant additive

This work aims to encapsulate anthocyanins and phenolic compounds extracted from a native Brazilian fruit peel - jabuticaba (Plinia cauliflora (Mart.) Kausel) and propolis from Tubuna (Scaptotrigona bipunctata) stingless bees, with great potential benefits for human health. The alginate encapsulation was conducted by the ionotropic gelation through the dripping into the CaCl₂ solution. Both raw extracts were characterized by TPC - total phenolic content (Folin-Ciocalteu), AA -antioxidant activity (DPPH and ABTS assays), and TMAC - total monomeric anthocyanin concentration (pH differential method); as well as their resultant mixture (2:1 jabuticaba/propolis). The obtained beads presented highly efficient encapsulation of total polyphenols (~98%) and monomeric anthocyanins (~89%), with spherical morphology and smooth surface obtaining a mean diameter between 200 and 250 μm. In vitro release study showed that JPE/alginate beads were completely disintegrated at pH 7.4 (intestinal pH), but they were resistant to gastric pH (1.2) presenting a slow release of about 40% in 240 min. This is the first report that encapsulates the mixture of jabuticaba and propolis extracts and may contribute to the utilization of a great source of bioactive compounds besides the potential pigment of anthocyanins, an alternative to natural and healthy food/beverage colorants.

Keywords: Anthocyanins; Plinia cauliflora; Polyphenolics; Scaptotrigona bipunctata.