Phenolic and tocopherol content of autumn olive (Elaeagnus umbellate) berries

Abstract

The objectives of this work were to characterize polyphenols and α- and γ-tocopherols in several commercial cultivars of Elaeagnus umbellate (autumn olive) berry. Acidic aqueous acetone extraction yielded the highest total phenol recovery, ranging from 190 to 275 mg gallic acid equivalents (GAE)/100 g fresh weight among berry cultivars. Berries were found to contain proanthocyanidins by reaction with 4-(dimethylamino)cinnamaldehyde. Normal phase HPLC analysis confirmed that the total proanthocyanidin content of berries ranged from 68 to 225 catechin equivalents/100 g dry weight. Proanthocyanidins were composed of 64 to 89% polymers with degree of polymerization >10, with lesser amounts of monomers through 5-mers. Total α- and γ-tocopherol ranged between 9 and 23 mg/100 g oil. The ratio of α- to γ-tocopherol varied from ~3:1 to 10:1 among autumn olive cultivars. Thus, the presence of highly polymerized proanthocyanidins and tocopherols should be considered in formulating functional foods with autumn olive berry.

Keywords

• Elaeagnus umbellate
• Autumn olive
• Polyphenol
• Proanthocyanidin
• Tocopherol