Herbal teas as a rich source of phenolic compounds

Phenolic compounds are of a considerable interest and have received more and more attention in recent years due to their bioactive functions. These components are known as secondary plant metabolites and also possess antimicrobial, antiviral and anti-inflammatory properties. The popular Latvian herbals – Calendula (Calendula officinalis L.), Lady’s-mantle (Alchemilla vulgaris L.), Yarrow (Achillea millefolium L.), Peppermint (Mentha × piperita L.) and Bellis (Bellis perennis L.) – are widely used for herbal teas. The objective of this study was to determine individual phenolic compounds in herbal infusions using high-performance liquid chromatography. The obtained results showed significant differences (p ˂ 0.05) of the phenolics content in the analysed herbal teas. The total content of the identified 14 phenolic compounds in Yarrow tea was on the average 136.76 ± 0.8 mg 100 g–1, in Peppermint tea 304.38 ± 10.7 mg 100 g–1, in Lady’s-mantle tea 319.53 ± 12.5 mg 100 g–1, in Calendula tea 586.36 ± 17.6 mg 100 g–1, but in Bellis tea it was 802.96 ± 21.3 mg 100 g–1. The dominant phenolic compound in Peppermint, Lady’s-mantle and Yarrow teas was rutin, but chlorogenic acid in Bellis tea. Calendula tea has an abundant quantity of sinapic acid.