Radical scavenging and iron-chelating activities of some greens used as traditional dishes in Mediterranean diet

Abstract

This study aimed at evaluating the antioxidative activity of nine different families of greens. Raphanus raphanistrum (wild radish), Anchusa azurea (bugloss), Daucus carota (wild carrot), Sonchus oleraceus (sowthistle), Papaver rhoeas (corn poppy), Malva sylvestris (blue mallow), Foeniculum vulgare (fennel), Cichorium intybus (chicory) and Salicornia europaea (jointed glasswort) are native to the Mediterranean and are commonly consumed as a salad or an ingredient in some recipes. The antioxidative activities, including the radical scavenging effects, inhibition of hydrogen peroxide (H₂O₂), and Fe²⁺-chelating activity, were studied. All samples showed antioxidant activity as a radical scavenger in the experiment using the DPPH• radical. The ratio between the slopes of the kinetic model was used to compare antioxidant efficiency of different greens. Greens also possessed antioxidative activity toward H₂O₂. Especially, greens exhibited a marked scavenging effect on H₂O₂ at 0.2 g/ml concentration. The Fe²⁺ ion-chelating activities of the samples except jointed glasswort were greater than 70%. The antioxidant activity of samples with different methods based on the inhibition of different reactions could not be compared. The current dietary guidelines include recommendations for an increase in the consumption of plant foods. Greens should provide an optimal supply of antioxidant substances in the diet.