Phenolic composition of hazelnut leaves: Influence of cultivar, geographical origin and ripening stage

▶ Hazelnut tree leaf presents high contents of flavonoids and phenolic acids. ▶ Hazelnut tree leaf is a potential source of natural antioxidants. ▶ Phenolic content in hazelnut leaves is mainly affected by the factor “crop year”. ▶ Genetic factors can also exert a moderate influence in phenolic compounds content. ▶ A seasonal pattern from May to September was observed.