Elderberry (Sambucus nigra L.) as potential source of antioxidants. Characterization, optimization of extraction parameters and bioactive properties

The present study aimed to characterize the nutritional value and potential use of elderberries as a source of antioxidant compounds. The chemical composition, fatty acids and phenolic compounds were determined for elderberries. The optimization of extraction parameters was designed with a Box-Behnken design coupled with response surface methodology (RSM) and desirability function analysis. The process parameters tested included extraction temperature, % of ethanol and pH, while response variables were global extraction yield, total phenolic and anthocyanins content (TAC), carotenoids and antioxidant activity. Analyses revealed that elderberry was a rich source of total soluble solids, proteins and polyunsaturated fatty acids (omega-3: 38.12 g/100 g and omega-6: 39.54 g/100 g fatty acids). Regarding phenolic compounds, elderberries were found abundant in flavonoids (rutin and quercetin), and phenolic acids (i.e. gallic acid and gentisic acid). Finally, numerical optimization indicated that the best extraction parameters were the following: temperature 60 °C, 50% of ethanol and pH 2.