Elderberry (Sambucus nigra L.) by-products a source of anthocyanins and antioxidant polyphenols

Elderberry industrial by-products can be a potential low cost source of some unique bioactive polyphenols. Hence, the main objective of this work was to perform a comparative study of the polyphenol profile of elderberry branches, the scavenging activity towards 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid, hydroxyl and nitric oxide radicals and to compare with those of the elderberry berries. Total phenolic compounds and anthocyanins were significantly higher in the berries when compared to the branches (1.68 and 3.21 times, respectively), nevertheless the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals scavenging activities were similar between the two materials, and branches extract presented a higher nitric oxide radical scavenging activity. A total of 23 polyphenolic compounds were detected in all samples, of which thirteen compounds were present both in berries and branches, including cyanidin 3,5-diglucoside, cyanidin 3-sambubioside-5-glucoside, cyanidin 3-glucoside and cyanidin 3-sambubioside. As elderberry production is increasing, as well the generation of associated by products, the polyphenolic composition of the elderberry branches opens the possibility of its valorization, using simple and relatively easy extraction procedures yielding extracts rich in polyphenols possessing a significant antioxidant activity, useful to other emerging industrial and agricultural applications. (C) 2016 Elsevier B.V. All rights reserved.