Total Antioxidant Activity, and Hesperidin, Diosmin, Eriocitrin and Quercetin Contents of Various Lemon Juices

Purpose: To investigate 38 natural and 62 branded lemon juices for their total antioxidant activities and flavonoid content.
Methods: The ferric reducing antioxidant power was applied to evaluation of antioxidant. Additionally quercetin, eriocitrin, diosmin and hesperidin contents were evaluated by high performance liquid chromatography (HPLC).
Results: Total antioxidant activity of the juices ranged from 91.38 ± 0.01 to 526.93 ± 0.12 μg/ml. The maximum contents of quercetin, hesperidin and eriocitrin 14.83 ± 2.83, 104.84 ± 12.58 and 10.68 ± 2.41 μg/mL, respectively. The natural juices had diosmin levels as high as 236.18 mL. The limit of detection (LOD) ranged from 0.15 μg mg-1 for hesperidine to 0.53 μg ml-1 for diosmin while the limit of quantification (LOQ) ranged from 0.27 μg mg-1 for hesperidine to 0.93 μg ml-1 for quercetin.
Conclusion: The developed method can also be applied to the determination of related extracts of orange cultivars as well as various extracts of medicinal plants.

Keywords
Antioxidant; Flavonoid; Hesperidin; Diosmin; Eriocitrin; Quercetin; Lemon juice