Phenolic compounds extracted by acidic aqueous ethanol from berries and leaves of different berry plants

Ye Tian, Jaana Liimatainen, Aino-Liisa Alanne, Anni Lindstedt, Pengzhan Liu, Jari Sinkkonen, Heikki Kallio, Baoru Yang

Food Chemistry and Food Development, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland.

Abstract

Phenolic compounds of berries and leaves of thirteen various plant species were extracted with aqueous ethanol and analyzed with UPLC-DAD-ESI-MS, HPLC-DAD, and NMR. The total content of phenolics was consistently higher in leaves than in berries (25–7856 vs. 28–711 mg/100 g fresh weight). Sea buckthorn leaves were richest in phenolic compounds (7856 mg/100 g f.w.) with ellagitannins as the dominant compound class. Sea buckthorn berries contained mostly isorhamnetin glycosides, whereas quercetin glycosides were typically abundant in most samples investigated. Anthocyanins formed the dominating group of phenolics in most dark-colored berries but phenolic acid derivatives were equally abundant in saskatoon and chokeberry berries. Caffeoylquinic acids constituted 80% of the total phenolic content (1664 mg/100 g f.w.) in bilberry leaves. B-type procyanidins and caffeoylquinic acids were the major phenolic compounds in hawthorn and rowanberry, respectively. Use of leaves of some species with prunasin, tyramine and β-p-arbutin, may be limited in food applications.

Keywords: Aromatic compounds; Berries; Ethanol extracts; Leaves; Phenolic compounds.