Fractionation and identification of the phenolic compounds of Highbush blueberries (Vaccinium corymbosum, L)

A scheme for the fractionation of flavonoid and nonflavonoid compounds is presented. The phenolic compounds of Highbush blueberries (cultivar 'Coville') were analysed by high performance liquid chromatography and thin-layer chromatography. Fifteen anthocyanins were identified as the 3-monoglucoside, 3-monogalactoside and 3-monoarabinoside of delphinidin, cyanidin, malvidin, peonidin and petunidin. No acyl anthocyanin was detected. Derivatives of malvidin and delphinidin were the most abundant; the 3-monogalactoside constituted 41% of the anthocyanin. Four flavonol glycosides were also identified as the kaempferol-3-O-glucoside, 3-O-glucoside, 3-O-galactoside and 3-O-rhamnoside of quercetin. The major phenolic acid was chlorogenic acid. After hydrolysis of the phenolic neutral fraction (FA), gallic, syringic and vanillic acids were identified by TLC. These acids appeared to be present in their ester forms, probably as glucoside esters.