Phenolic Content of a Commercial Sambucus nigra Preparation

Elderberries contain various flavonoids such as hyperoside, isoquercitrin and rutinoside and up to 1% of anthocyanins [1]. Aim of this investigation was to evaluate the flavonoid content in a commercially available elder product (elderberry juice concentrate prepared from 120g fresh berries supplemented with elderflower juice and extract based on 3.9g dried flowers per 200 mL). Methods: We used the method described by Kammerer et al. [2]. The liquid product was extracted three times with acidic methanol (approx. 60min per extraction). After evaporation, the residue was dissolved in 1 mL of acidified bidistilled water (pH 3). Polyphenols separated by HPLC were quantified using commercially available standards (calibration curves) or, if standards were not available, corrected by a molecular weight factor according to Chandra et al. [3]. Phenolic compounds were characterized and quantified using HPLC with diode array and mass spectrometric detection. Results: Five major compounds were detected at 320 nm (hydroxycinnamates) and 370 nm (flavonols) and unambiguously identified as neochlorogenic acid (125mg/L), chlorogenic acid (623mg/L), rutin (1441mg/L), kaempferol-3-rutinoside (44mg/L), and isorhametin-3-rutinoside (324mg/L). Only very small amounts of anthocyanins were found in the product (4mg/L). Conclusion: Our results show that rutin and chlorogenic acid were the predominant phenolic compounds present in the product. It seems likely that most of the antioxidative compounds have been destroyed during preparation of the proprietary juice concentrate.

References: [1] Anonymous. (1994) Hagers Handbuch der Pharmazeutischen Praxis 6: 579–86, Springer Press, Heidelberg. [2] Kammerer, D. et al. (2004) J. Agric. Food Chem. 52: 4360–4367. [3] Chandra, A. et al. (2001) J. Agricult. Food Chem. 49: 3515–3521.