Differences in Chemical Composition and Antioxidant Capacity Among Different Genotypes of Autumn Olive (Elaeagnus umbellate Thunb.)

Fruit from six genotypes of autumn olive (Elaeagnus umbellate Thunb.); Brilliant Rose, Delightful, Jewel, Natural 1, Natural 2 and Sweet N Tart; were evaluated for fruit quality, phenolic content, carotenoids, antioxidants, antioxidant capacity, and antioxidant enzyme activity. The fruit soluble solids content (SSC), titratable acids (TA), total carotenoids, and total phenolic content varied with genotypes. Soluble solids content (SSC) in six genotypes of autumn olive ranged from 10.6 to 18.4 %, while titratable acids ranged from 0.79 to 1.29 %. Jewel had the highest SSC and Sweet N Tart had the highest TA. Fructose and glucose were the two predominant sugars, and malic acid was the predominant organic acid found in autumn olive fruit. Jewel and Sweet N Tart cultivars had the highest sugar and organic acid content among the six genotypes. Autumn olive had potent free radical scavenging activities for 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH), 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), peroxyl radical (ROO), superoxide radicals (O2 ), hydroxyl radicals (OH), and singlet oxygen (O2). Autumn olive also had high activities of antioxidant enzymes including glutathione peroxidase (GHS-POD), glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (AsA-POD), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDAR). Among the six genotypes, Brilliant Rose and Jewel had the highest levels of antioxidants and antioxidant enzyme activity.