Impact of phenolic compounds and vitamins C and E on antioxidant activity of sea buckthorn (Hippophae rhamnoides L.) berries and leaves of diverse ripening times

Bioactive compounds demonstrating antioxidant activity were analyzed in berries and leaves of nine cultivars of sea buckthorn (Hippophae rhamnoides L.) of various ripening times. Total polyphenols were ranging between 0.70-3.62 g GAE.kg(-1) (berries) and 1.88-3.72 g GAE.kg(-1) (leaves). Leaves were significantly richer source of total flavonoids (14.40-49.44 mg RE.kg(-1)) in comparison with berries (0.55-4.11 mg RE.kg(-1)). Phenolic compounds, carotenoids and vitamins were determined using high-performance liquid chromatography with a diode array detection. The content of vitamin C was 0.98-3.65 g.kg(-1) in berries and 22.81-46.32 g.kg(-1) in leaves, vitamin E content was 6.98-29.91 g.kg(-1) in berries and 71.54-153.99 g.kg(-1) in leaves. Distribution of individual phenolic compounds varied, their total content in berries was considerably lower (76.1-205.2 mg.kg(-1)) than in leaves (1477.7-8709.0 mg.kg(-1)). Regarding antioxidant activity, Raisa and Slovan (berries) and Bojan and Maslicnaja (leaves) were evaluated as the best cultivars.