Researches on mixed herbal teas those are sold as winter tea in the market

Mixed herbal teas are formulated with similar or different contents of medicinal herbs to improve health. Marketing winter teas are composed of medicinal herbs to prevent and treat the common cold symptoms. People expect these teas to be highly effective safe and in a good quality. Antioxidants are effective in improving immunity and beneficial in the treatment of diseases such as colds and flu. Thus they are expected to be in high ratio in winter tea formulations.The antioxidant activity of these teas is mainly attributed to their phenolic content. The correct plant species and the quality of plant materials in the mixture are important in terms of antioxidant activity. The number of studies on the herbal tea mixture formulations is limited in the literature. In this study, the total flavonoid, total phenolic contents and the antioxidant activity of 10 different brands of mixed herbal tea samples marketing as winter tea were investigated. Macroscopic, microscopic examination and thin layer chromatographic (TLC) analysis of the each plant material in the composition were studied, and the findings were evaluated with the criteria in the related pharmacopoeia monographs. It was determined that the total flavonoid content was between 2.54 - 16.32 mg QE/g, and the total phenol content was between 23.16 - 103.20 mg GAE/g, and the antioxidant activity was determined by the DPPH radical scavenging activity test and found between 41.17-191.20 mg TE/g. Among the tea formulations the highest qualification was determined for the Sample-1. Sample-1 was found to be composed of sage leaf, everlasting flower, marshmallow flower, myrtle leaf, roselle and rosehip. Among these plant materials, sage leaf (three lobed), everlasting flower, marshmallow flower, roselle and rosehip materials were found to comply with the pharmacopoeia criteria. It was noteworthy that roselle and rosehip were shared components of all winter tea samples. None of winter tea formulations was found in which all components were complied with the pharmacopoeia standards. As a result of this study; It was emphasized that the quality controls of the mixed herbal teas including winter teas on the market should be done to protect the public health. Keywords: Winter teas, Mixed herbal teas, Antioxidant activity, Total phenol content, Total flavonoid content, Pharmacopoeia analysis