Naslov
Antioxidant activity of aqueous tea infusions prepared from oregano (Origanum vulgare L. spp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.)

Autori
Kulišić, Tea ; Dragović-Uzelac, Verica ; Miloš, Mladen

Izvornik
Food Technology & Biotechnology (1330-9862) 44 (2006), 4; 485-492

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
antioksidacijska aktivnost; vodene infuzije; Lamiaceae; mravinac; timijan; majčina dušica
(antioxidant activity; aqueous tea infusion; Lamiaceae; oregano; thyme;)

Sažetak
Using a multiple-method approach, antioxidant activity of aqueous tea infusions prepared from oregano (Origanum vulgare L. spp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) were tested in relation to their chemical composition. Total phenolics, flavonoids, catechins and anthocyanins content were determined by spectrophotometric methods. Oregano aqueous tea infusion had the highest amount of total phenols (12 500 mg/L GAE) and flavonoids (9 000 mg/L GAE). Identification of polyphenolic compounds in aqueous tea infusions, by HPLC-PDA analysis, showed a dominant presence of rosmarinic acid: 123.11 mg/g in oregano, 17.45 mg/g in thyme, 93.13 mg/g in wild thyme. Antioxidant activity of aqueous tea infusions was evaluated using four antioxidative methods (the b-carotene bleaching method, the 2, 2&cent ; -diphenyl-1-picrylhydrazyl-DPPH radical scavenging method, the thiobarbituric acid reactive species-TBARS assay and the induction period of lard oxidation-Rancimat assay). The results are compared with natural (ascorbic acid and a-tocopherol) and synthetic antioxidants (butylated hydroxytoulene BHT and butylated hydroxyanisole BHA). Oregano aqueous tea infusion showed the strongest antioxidant activity by three methods (the b-carotene bleaching method, DPPH radical scavening method and Rancimat assay), while thyme and wild thyme showed weaker and relatively similar antioxidant activity.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Prehrambena tehnologija

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