Carotenoids, Tocopherols and Antioxidant Activity of Lipophilic Extracts from Sea Buckthorn Berries (Hippophae rhamnoides), Apricot Pulp and Apricot Kernel (Prunus armeniaca)

Abstract

A healthy human diet requires the daily consumption of fruits and vegetables rich in bioactive compounds. Sea buckthorn berries ( Hippophae rhamnoides L.) and apricot fruits ( Prunus armeniaca L.) are cultivated and appreciated in Romania both as fresh fruits and as derived products. Characterized by a complex chemical composition, sea buckthorn is rich in unsaturated lipids, carotenoids and tocopherols. Except for β-carotene content, less is known about other lipophilic compounds in apricot fruits. The aim of this paper was to separate and quantify the individual carotenoids, tocopherols and tocotrienols in sea buckthorn, apricot pulp and kernels and also to determine the antioxidant activity of the lipophilic extracts using the TEAC method. Chemical characterization of lipophilic extract was performed by HPLC with PDA and fluorescence detection. The total carotenoid content was 17.19±1.4 mg/100g F.W. in sea buckthorn; 3.51±0.25 mg/100g F.W. in apricot fruits and 0.58±0.04 mg/100 g F.W. in apricot kernels. The major carotenoids in sea buckthorn were β-carotene, zeaxanthin and β-cryptoxanthin esters. Apricots fruits are rich in β-carotene and its geometric isomers while in kernels we could properly identified only lycopene. The α-tocopherol concentration was higher in sea buckthorn (46 mg/kg) than in apricot fruits (1.09 mg/kg) while apricot kernel contain large amounts of γ-tocopherol (111 mg/kg). Sea buckthorn fruits showed the highest antioxidant capacity, correlated with a high content of both tocopherols and carotenoids.