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Extraction and separation of polyphenol classes in chokeberry and elderberry fruit

Chokeberry (Aronia melanocarpa) and elderberry (Sambucus nigra L.) fruits are one of the richest dietary sources of polyphenols, a natural bioactive compounds. Anthocyanins are the most prevalent polyphenols in these fruits although other classes such as phenolic acids, flavonols, and flavanols are present as well. Those phenolic subgroups can show different bioactivities. That is why it can often be apropriate to examine bioactivities of these subgroups separately. The aim of this study was to to extract and determine polyphenols from chokeberry and elderberry and to separate polyphenol subgroups present in the extracts. The extraction was conducted using 80 % methanol as a solvent with the help of ultrasonic bath, and repeating the extraction step four times. Polyphenol subgroups found in extracts were separated using gel chromatography fractionation with Sephadex LH-20 as a stationary phase and different percentages of methanol in water as a mobile phase. Polyphenols in extracts and fractions were analysed using reversed-phase high performance liquid chromatography (RP- HPLC). The amount of polyphenols extracted from chokeberries and elderberries was 15557 and 10009 mg kg-1 of fresh fruit weight, respectively. Four fractions were separated for each fruit. Flavanols were eluted in fraction 1 (100 % and 100 %) and phenolic acids in fraction 2 (100 % and 100 %), anthocyanins were dominant in fraction 3 (91 % and 55 %), while flavonols were prevalent in fraction 4 (53 % and 100 %) for chokeberry and elderberry, respectively. Using gel-chromatography fractionation, four fractions containg different polyphenol subgroups were seeparated which could be useful in further research.

berries ; polyphenols ; extraction ; separation ;

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