Effect of Infusion Time on the Phenolic Content and Free Radical Scavenging Capacity of Olive Leaf Tea

Tütenocaklı T., Türker G., Arifoğlu N., Coşkun Y.

V. International Joint Science Congress of Materials and Polymers (ISCMP), 29 September 1 October 2021, Burdur Turkey, Burdur, Turkey, 29 September - 03 October 2021, pp.137

  • Publication Type: Conference Paper / Summary Text
  • City: Burdur
  • Country: Turkey
  • Page Numbers: pp.137
  • Çanakkale Onsekiz Mart University Affiliated: Yes


Olive leaf tea is traditionally used in folk medicine, especially in the Mediterranean region. It has been used for

a long time as antidiabetic and antihypertensive herbal drug. Research on the health effects of olive leaf

preparations and extracts has revealed that olive leaves have antimicrobial, antioxidant, hypoglycemic,

hypocholesterolemic, and anti-atherosclerotic effects. All these positive effects are associated with the content

of bioactive compounds such as phenolics, flavonoids, tannins, and steroids present in olive leaves. A number

of studies have shown that the bioactive compounds content may vary depending on the cultivar, climatic

conditions, as well as the way of tea infusion preparation. Therefore, in the present study, the effect of infusion

time on the phenolic, flavonoid, and radical scavenging capacity of olive leaves from 3 different olive cultivars

(Ayvalik, Gemlik, and Kalamata) was investigated. The infusions were prepared with ground olive leaves that

were immersed in deionized boiling water for 1, 3, and 5 minutes. The total phenolic content of the infusions

was in the range between 8.03 and 9.81 mg gallic acid equivalent / g dry leaves. The total phenolic content of

the infusions of Ayvalik and Kalamata leaves significantly increased with increasing infusion time (p<0.05). On

the other hand, the total flavonoid content of the infusions varied from 4.36 to 4.92 mg rutin / g dry leaves,

though no statistical difference was detected for all preparations. The evaluation of the total radical scavenging

capacity, measured with 2,2-diphenyl-1-picrylhydrazyl (DPPH) method revealed that the radical scavenging

activities of the prepared infusions, in terms of IC50 inhibition values, changed from 2.28 to 2.89 µg /ml.

Subsequently, it was found out that with increasing infusion time the amount of total phenolics increase in the

olive leave tea preparations.

Keywords: Olive Leaves, Infusion Time, Phenolics, Flavonoids, Free Radical Scavenging,