Assessment of phenolic composition and antioxidant activity of fermented Andean blackberry beverage enriched with medicinal plants of Ecuador

In recent years there has been a great interest in functional beverages with antioxidant capacity that impart various health implications upon consumption due to the presence of various bioactive components, like phenols. Fruit juices are excellent matrices for the delivery of active components for these functional beverages. This research was focused on developing and testing the biological activity of a new fermented blackberry (Rubus glaucus Benth) beverage enriched with different plants as a new product on the functional food market. Several Ecuadorian species (spices, aromatic, and medicinal) have been tested for the highest antioxidant activity and phenolic content. Methods like Folin Ciocalteu, α-diphenyl-α-picrylhydrazyl free-radical-scavenging method (DPPH), free-radical-scavenging activity (ABTS), and Ferric reducing antioxidant power (FRAP) were used. Among the tested plants, arrayán (Myrcianthes hallii), plantain (Plantago major), ishpingo (Ocotea quixos), and ataco (Amaranthus quitensis) were selected. The study demonstrates the ability of medicinal plants to improve the total phenolic content and antioxidant capacity, but also the sensory properties of the functional drink compared to the blackberry fermented drink. The highest values of the analyzed characteristics (total phenolic content, antioxidant capacity, sensory evaluation), were obtained in the case of the treatment consisting of fermented blackberry beverage enriched with 4 g of medicinal plants.