Comparison of Antioxidant Activity and Free Radical Scavenging Activity of Gardenia Jasminoides with Three Different Regional Sources (P17-005-19)

To compare the antioxidant activity and free radical scavenging activity of three different regional sources of Gardenia Jasminoides Gardenia Jasminoides grown in multiple regions in Asia (mainly in China and Korea) was commonly used as a natural yellow dye, and has been one of the popular traditional Chinese medicines since the discovery of its biological property a few decades ago. In this experiment, three different samples were used; GJ dry mass powder from South Korea (GK), GJ dry mass powder from China (GC), GJ extract powder(extracted with 50% ethanol and ended by dry freeze process) from dry mass powder from South Korea. (GE). To investigate the antioxidant activities, we employed the following parameters: DPPH radical scavenging activity, ABTS radical scavenging activity, Total polyphenol content, and Total flavonoid content. Total polyphenol content was based on gallic acid standard curve and total flavonoid content was measured using quercetin as standard. The DPPH radical scavenging activity was experimented using 1 mM DPPH methanol standard solution (the solution standardized in O.D value of 0.95∼0.99 at 525 nm), and the ABTS scavenging activity was carried out using ABTS standardradical stock solution (the solution standardized in the O.D. value 0.7 ± 0.02 at 734 nm). The DPPH radical scavenging activity is highest in ethanol extract powder (88.8%) and lowest in dry mass China powder (65.5%). The ABTS radical scavenging activity is highest in ethanol extract powder (100.2%) and lowest in dry mass China powder (98.4%) with no significant differences among samples. In total polyphenol contents assay, China dry mass powder showed the highest contents of 3.0 g GAE/100 g, and the lowest contents of 1.5 g GAE/100 g dry mass powder(Korea) (GAE: gallic acid equivalent). In total flavonoid contents assay, the highest content is in China dry mass powder with 35.4 g QE/100 g dry mass powder, and the lowest content was observed in domestic South Korea powder of 10.2 g QE/100 g dry mass powder (QE: quercetin equivalent). Although China dry mass GJ powder showed the highest polyphenol and flavonoids contents, the free radical scavenging activity was observed highest in ethanol extract powder of GJ. Thus we may suggest that the extraction method would be a powerful way to get improved antioxidant activity and free radical scavenging activity of the raw GJ products according to the purpose of study. Department of Food and Nutrition, Sookmyung Women's University, Republic of Korea.