Polyphenolic and Antioxidant Properties of Elderberry (Sambucus) Fruits

Abstract

Elderberries (Sambucus sp.) are rich in phenolics which could provide protection of LDL against oxidation. S. Canadensis (S.c.) and S. nigra (S.n.) are native to N American and Europe, respectively. The antioxidant and phenolic properties of their water soluble phenolic extracts could be important for human nutritional health. S.c. cultivars (Johns, CSAM72, Adams II, Brush Hill 2, Maxima, Scotia, Eridu 1, and York) and S.n. (Albo‐variegata, Purpurea, Samdal, and Guincho Purple) were cultivated at the USDA ARS National Clonal Germplasm Repository, Corvallis, Oregon. Ripe fruits were harvested, frozen at −80C, and aqueous extracts prepared/pasteurized. Phenolic content (gallic acid equivalence mg/L; GAE) for S.n. (6751 ± 528) was significantly (P=0.004) greater than S.c. (5271 ± 806). Effects of elderberry antioxidants on human LDL oxidation (5μM Cu++) lag‐time (A234nm) was examined at extract dilutions of 1:10,000, 1:50,000 and 1:100,000. At the 1:10,000 dilution, antioxidant activity for S.n. (201±12 min) was significantly higher than S.c. (138±12 min), 1:50,000 and 1:100,000 dilutions were not associated with significant antioxidant activity. Higher GAE was correlated with increased lag‐time (R2= 0.55). Understanding differences in elderberry antioxidant activity may be important for development of elderberry nutritional health applications and cultivar selection.