Radical Scavenging, Antioxidant and Ferric Reducing Activities of Commercial Mineral Water Enriched with Fruit and Ready to Drink Flavoured Teas

摘要

The antioxidant properties of the commercial mineral water enriched with fruit and flavoured teas ready to drink were evaluated and compared with total phenolics, flavonoids, antocyanins and ascorbic acid content. Spectrophotometrical methods were used to evaluate total phenols, flavonoids and antocyanins content. Vitamin C content was also determined by titration with DIF. To screen the antioxidant properties DPPH and ABTS radical method, β-carotene bleaching test and FRAP assay were used. Mineral water enriched with fruit contains significantly higher level of total phenolics comparing with analyzed ready to drink flavoured teas. Generally, mineral water enriched with fruit exhib-ited a stronger radical scavenging activity compared to flavoured teas in both DPPH and ABTS test. Using the FRAP as-say that measured the reducing ability of antioxidants flavoured ready to drink tea ranged from 1.42 to 3.80 mM Fe(II) while mineral water enriched with fruit ranged from 7.01 to 38.46 mM. Mineral water enriched with fruit also exhibited a higher inhibition of linoleic acid oxidation particularly sample FWE4 that showed IC50 values of 0.70 and 1.61 v/v at 30 and 60 min of incubation. Collectively, our results improve the knowledge concerning the antioxidant properties of differ-ent commercially ready to drink teas and fruit enriched mineral waters available on the Italian consumer market that could be effectively considerd as functional drinks.