The quantity of biologically active substances in purple coneflower as influenced by the preparation methods and drying technologies

Abstract

The purple coneflower (Echinacea purpurea (L.) Moench) is one of the most promising medicinal plants in Lithuania. More than 200 biologically active substances, and the most important components among them – phenolic acids, including chicoric acid are accumulated in the medicinal plant raw material. Moisture content of purple coneflower raw material can reach up to 80% just after harvest, thus different drying technologies are used to reduce moisture content and this process involves losses of bio-active substances. An experimental comparative research was carried out to determine the influence of preparation and drying methods of purple coneflower for drying process and quality. It was found that weight of purple coneflower stems accounted for 48.7% of the total plant weight and they formed the largest above-ground part of a plant, which was by 1.5 and 2.6 times higher than the weight of leaves and flowers, respectively. In flowers, leaves and stems of purple coneflower, phenolic acids constituted the biggest part of phenolic compounds. The distribution of phenolic acids in different above-ground plant parts was from 64.66 ± 3.23 to 92.08 ± 4.60 mg gd.m.-1 RE (rutin equivalent) in flowers, from 47.46 ± 2.37 to 76.9 ± 3.85 mg gd.m.-1 RE in leaves and from 15.2 ± 1.05 to 22.99 ± 1.15 mg gd.m.-1 RE in stems.