Phenolic profile of hazelnut (Corylus avellana L.) leaves cultivars grown in Portugal.

In this study, phenolic compounds of hazelnut leaves of 10 different cultivars with the same cultural, geographical, geological and climatic conditions were analyzed by HPLC/DAD and HPLC/DAD/MS/MS - ESI. Eight phenolic compounds (3-caffeoylquinic acid, 5-caffeoylquinic acid, caffeoyltartaric acid, p-coumaroyltartaric acid, myricetin 3-rhamnoside, quercetin 3-glycoside, quercetin 3-rhamnoside and kaempferol 3-rhamnoside) were identified and quantified. All of the analyzed samples showed a similar phenolic profile, in which myricetin 3-rhamnoside and quercetin 3-rhamnoside were the major compounds and caffeoyltartaric and p-coumaroyltartaric acids were present in vestigial amounts.