Nutritional Composition and Antioxidative Activity of Different Parts of Taraxacum coreanum according to Drying Methods

This study compared the nutritional composition and antioxidative activity of different parts of Taraxacum coreanum (aerial parts and roots) according to different drying methods (natural drying and freeze-drying). There were no significant differences in vitamin C content in roots depending on the drying methods. However, vitamin A (P<0.01), E (P<0.001) and C (P<0.001) content of aerial parts, and vitamin A (P<0.001) and E (P<0.05) content of roots were significantly higher after freeze-drying compared to natural drying. For organic acids, the oxalic acid content of the aerial parts and roots were the highest. The total polyphenol and total flavonoid content in extracts from the aerial parts (P<0.01) and roots (P<0.05) were significantly higher after freeze-drying compared to natural drying. In addition, the total polyphenol and flavonoid content, DPPH radical scavenging activity, and antioxidative index from the natural drying and freeze-drying of Taraxacum coreanum extracts were significantly higher in the aerial parts compared to the roots (P<0.05). These results suggest that the nutritional composition and antioxidative activity of Taraxacum coreanum are higher in the aerial parts compared to the roots, and higher after freeze-drying compared to natural drying. Therefore, the aerial parts of Taraxacum coreanum could be suggested as an antioxidative functional food source.

Diversity of Endophytic Fungi Associated with Taraxacum coreanum and Their Antifungal Activity

Endophytic fungi were isolated from healthy leaf and root samples of Taraxacum coreanum. Of the 72 isolates recovered, 39 were from leaves and 33 from roots with an isolation frequency of 54% and 46%, respectively. Based on ITS sequence analysis, 72 isolates were classified into 19 genera of which 17 were under the phylum Ascomycota and 2 were under Basidiomycota. Diverse genera were found and Alternaria, Cladosporium, Fusarium and Phoma were dominant. Out of 19 genera, Apodus, Ceriporia, Dothideales, Leptodontidium, Nemania, Neoplaconema, Phaeosphaeria, Plectosphaerella and Terfezia were new to Korea. Seventy two isolates were screened for antifungal activity, of which 10 isolates (14%) were found active at least against one of the tested fungi. Isolate 050603 had the widest antifungal spectra of activity, and isolates 050592 and 050611 were active against three plant pathogenic fungi.