Elderberry (Sambucus nigra L.) juice as a novel functional product rich in health-promoting compounds

The medicinal herbs of the Balkan Peninsula are highly represented in traditional medicine. The connection between traditional and modern life and health is reflected in the creation of new food products with added value. In this study, the plant species Sambucus nigra L. was used to obtain freshly pressed juice, whose chemical composition and various biological activities were evaluated. The most abundant compounds were phenolic acids: protocatechuic and chlorogenic acid, as well as flavonoids: quercetin-3-O-hexoside, quercetin, and rutin. The analyzed juice was very rich in total phenolic compounds (1945 mg GAE per mL juice), and a significant anthocyanin concentration was observed (30.85 mg Cy-3-GE per mL juice). Bioactivity testing revealed that elderberry juice was an extremely potent agent in the process of neutralizing NO free radicals (53.06 g TE per L juice), while in reducing over-enzyme activity, the best result was achieved in the inhibition of tyrosinase enzyme (54.70 mg KAE per g of juice).