Impact of analysis method on anthocyanin content of elderberry products

Abstract

Knowledge of the anthocyanin content is required to pre-estimate the potential antioxidative or antiaging effects of food supplements. Aim of this investigation was to compare the anthocyanin contents of two elderberry products by using different analytical methods. Methods: We used (A) a commercial dietary supplement based on elderberry juice concentrate prepared from 120g fresh berries and supplemented with elderflower juice and extract based on 3.9g dried flowers per 200ml and (B) an elderberry juice mother concentrate (prepared in a ratio of 6.5:1 by Wild (Eppelheim, Germany)) and employed (i) the spectrophotometric method described in the French Pharmacopoeia (1), (ii) the pH-differential spectrophotometric technique (2) and, (iii) HPLC analysis with mass spectrometric identification of the cyanidin derivatives (3,4). Results: The anthocyanin contents were (i) 762mg/L at 528 nm, (ii) 85,4mg/L at 513 nm and (iii) 4mg/L (minute amounts of cyanidin-3-glucoside (0.6mg/L), cyanidin-3-sambubioside (2.2mg/L) and cyanidin-3-sambubioside-5-glucoside (1.2mg/L) in A and (i) 6400mg/kg at 528 nm, (ii) 17200mg/kg at 513 nm and (iii) 15430mg/kg (13705mg/kg cyanidin-3-sambubioside, 1725mg/kg cyanidin-3-sambubioside-5-glucoside) in B. Conclusion: Our results show that the results obtained from the determination of anthocyanins are strongly affected by the method employed. Hyphenated techniques such as HPLC combined with diode array and mass spectrometric detection appear to be most promising. Less sensitive methods consider more or less also degradation products. If food supplements claim for any clinical effects associated with anthocyanins, they must provide correct values.