Antioxidant Properties of Some Herbal Teas (Green tea, Senna, Corn Silk, Rosemary) Brewed at Different Temperatures

Abstract

Some non-wood forest products are brewed and consumed as tea. Among the reasons for the consumption of herbal tea, digestive problems are located in the first row. Antioxidants help to human body for arranging digestive and immune system. Herbal tea is brewed in various ways such as boiling at different durations or waiting in hot water at different temperatures etc. Type of brewing can affect to bioactive properties of herbal tea. In this study, it was investigated the bioactive properties (total phenolic content, total flavonoid content, condensed tannin content and antioxidant properties) of some herbals brewed (Green tea / Camellia sinensis., senna / Cassia sp., corn silk / Zea mays, rosemary / Rosmarinus officinalis) at different temperature. These herbs were brewed for 10 minutes at 60 o C, 80 o C and 100 o C temperatures. After cooling, total phenolic, flavonoid content, total condensed tannin content and antioxidant properties of these herbs were determined. Consistently, the highest results were found in the tea brewed at 100 o C. The highest total flavonoid (0.305 ± 0.005 mg QE/g) and ferric reducing ability (670.150 ± 2.121 µmol FeSO47H2O/g) was in Rosmarinus officinalis. The highest condensed tannin (9.443 ± 0.524 mg CE/g) and the highest total phenolic content (4.872 ± 0.005 mg GAE/g) was in Camellia sinensis and Cassia sp., respectively.

LC-ESI-QTOF-MS/MS Characterisation of Phenolics in Herbal Tea Infusion and Their Antioxidant Potential

“…TPC was measured by following a modified version of a previous method [40]. A total of 25 µL of Folin-Ciocalteu reagent (1:3 diluted with water) was mixed with 25 µL sample and 200 µL of Milli-Q water and incubated in the dark for 5 min at 25 • C. A sodium carbonate solution (10%, w/w) of 25 µL was then added and the mixtures were incubated at 25 • C for 60 min before absorbance was measured at 765 nm.…”

Determination of Antioxidant and Oxidant Potentials of Thymbra spicata Collected from Duhok-Iraq

“…In addition to their use as food, plants have been used for many purposes such as taste and fragrance, medicine, shelter construction, firewood and weapon making from past to present. In addition, extracts prepared from herbs called medicinal plants have been used in the treatment of many diseases (Shyur et al, 2005;Kılıç et al, 2017). After the beginning of the 19th century, drugs started to be made using the active substances found in the plants and the pharmaceutical industry was born.…”

Antioxidant and Antimicrobial Activities of Salvia multicaulis

“…Secondary metabolites that plants usually produce under stress are non-nutritious compounds, however they are quite important in medicinal uses. It was reported that these herbaceous compounds possess several biological activities as antioxidants and antimicrobials (Orangi et al, 2016;Pasdaran et al, 2017;Kılıç et al, 2017).…”