D. MIHAYLOVA1, L. GEORGIEVA1, I. ZHELEV2 and I. DIMITROVA-DYULGEROVA3
1 University of Food Technologies, Department of Biotechnology, BG – 4000 Plovdiv, Bulgaria
2 Medical University of Varna, Department of Pharmacognosy, Faculty of Pharmacy, BG – 9000 Varna, Bulgaria
3 Plovdiv University “Paisii Hilendarski”, Department of Botany, Faculty of Biology, BG – 4000 Plovdiv, Bulgaria
Mihaylova, D., L. Georgieva, I. Zhelev and I. Dimitrova-Dyulgerova, 2013. Influence of the extraction conditions over the antioxidant activity of Carduus thoermeri. Bulg. J. Agric. Sci., Supplement 2, 19: 61–64
The influence of the extraction technique over the antioxidant properties of C. thoermeri Weinm. water extracts, expressed as Trolox equivalent antioxidant capacity (TEAC), was studied using DPPH (2,2-diphenil-1-picrylhydrazyl) scavenging, ABTS (2,2′-azino-bis-3- ethylbenzothiazoline-6-sulfonic acid) scavenging and reducing power assays. The phenolic concentration in the examined extracts, calculated as mg gallic acid equivalent (GAE)/g dry weight (DW), ranged from 7.65 ± 0.91 to 19.57 ± 1.06 mg GAE/g DW. The results from the total phenolics assay and the antioxidant activity tests were significantly correlated. Among the different C. thoermeri water extracts the decoct shows higher antioxidant activity and content of total phenolic compounds, which suggested that polyphenols were responsible for the antioxidant abilities.