Characterization of metabolite profiles of leaves of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.).

Leaves of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) are potential raw materials for food and health care products. Targeted (HPLC-DAD, HPLC-MS, and GC-FID) and nontargeted ((1)H NMR) approaches were applied to study the metabolomic profiles of these leaves. Chlorogenic acid was the major phenolic compound in bilberry leaves and arbutin in lingonberry leaves. Flavonol glycosides were another major group of phenolics in bilberry [5-28 mg/g DM (dry mass)] and lingonberry (15-20 mg/g DM) leaves. Contents of fatty acids were analyzed using GC-FID. The changes in the metabolomics profile during the season were apparent in bilberry but not lingonberry leaves. Negative correlation was found between the contents of lipids and phenolics. The consistency between the key results obtained by targeted and nontargeted analyses suggests nontargeted metabolomic analysis is an efficient tool for fast screening of various leaf materials.