Antioxidative activity of roasted Pueraria lobata root extracts

We evaluated the antioxidative activity of extracts of P. lobata root depending on roasting conditions. P. lobata roots were roasted at three different temperature at 150℃, 200℃, and 250℃ and three different time at 10 min, 20 min, and 30 min respectively. Roasted P. lobata root was extracted using water at 85℃ for 6 h and filtered using filter paper, followed by then evaporated (12±0.3 °Brix) and freeze-dried. The concentration of maker compound puerarin was determined using a high performance liquid chromatography system. 2 phenolic compounds, flavonoid contents, and antioxidant activities of the extract powder were evaluated. Puerarin contents, Phenolic compounds, and flavonoid contents of roasted P. lobata root were higher than those of unroasted P. lobata root. The results of DPPH and ABTS showed that roasted P. lobata root possessed higher antioxidant activity than unroasted P. lobata root. This study suggested that roasting process could be applied to P. lobata root in order to achieve its high quality and functionality.