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Antioxidant activity of Mediterranean food: The case of cannonau wine, myrtle berries liqueur and strawberry-tree honey

A diet rich in antioxidant compounds is essential in preventing oxidative damage in humans. The Mediterranean diet is famous worldwide for being rich in antioxidants. Among these antioxidants, polyphenols are a group of molecules with proved antioxidant properties and protective effects against LDL oxidation and platelets aggregation. The aim of this work was to use different assays to evaluate the antioxidant properties of three typical food products from the Mediterranean area and to correlate these activities with their phenolic content. For this purpose, a red wine (cv. Cannonau ), a liqueur obtained by cold maceration of myrtle ( Myrtus communis L.) berries and a bitter honey obtained from strawberry-tree flowers ( Arbutus unedo L.) were analyzed. The total phenols (TP) content was measured by spectrophotometric determination with a modified Folin-Ciocalteau method and phenolic compounds were identified and dosed by LC-DAD-MS (Rosa et al , 2011 ; Tuberoso et al , 2010). Antioxidant activities were evaluated with the DPPH, FRAP and ABTS assays and the direct vasodilatory effects were assessed using norepinephrine preconrtracted rat aortic rings. Cannonau wine and myrtle liqueur showed high levels of TP (1732.0±98.7 and 1840.9±10.8 mg GAE/kg, respectively), linearly correlated to FRAP, ABTS and DPPH values. Their maximal vasodilatory activity was 62±4% and 53±3%, respectively. Although straw-berry tree honey contained relatively high levels of phenolic compounds (930.8 mg GAE/kg), it did not induce significant vasodilation, and even at the highest dose tested (0.206 g/L). These results indicate that foods with high levels of phenolics should be studied using several antioxidant assays before being recommended to the public as functional foods.

wine; liqueur; honey; antioxidant; vasodilation

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