Phenolic composition of fruits from different cultivars of red and black raspberries grown in Poland

Abstract

Fruits of 11 varieties of Rubus idaeus and 1 variety of Rubus occidentalis cultivated in Poland, were analyzed in terms of phenolic composition. The qualitative and quantitative determination of phenolics was performed by means of HPLC-DAD coupled with ESI–MS detector. Quantitative determination of anthocyanins, revealed significant differences in the levels of major anthocyanins in most red raspberry varieties, of which cyanidin 3-O-sophoroside was the most prevalent one. Black raspberries displayed 4–11 times more anthocyanin content compared to red raspberries, with the dominating anthocyanins being cyanidin 3-O-rutinoside and cyanidin 3-O-xylosyl-rutinoside.Sanguiin H-6 was the main ellagitannin identified in all varieties, with ‘Beskid’, ‘Laszka’, ‘Polana’ and ‘Litacz’ standing out as the richest sources of sanguiin H-6. Ellagic acid was at similar, low concentrations, with the highest levels observed in ‘Willamette’. A number of other compounds belonging to flavonols, flavan-3-ols and phenolic acids, were found at much lower levels than anthocyanins and ellagitannins, with the presence of procyanidins B1 and B2 being reported for the first time in the fruits of black raspberries. Data obtained on the variation in content of major and minor phenolic compounds between raspberry varieties highlights the most valuable cultivars to be used as a dietary source of phenolic compounds.