Background : This study was performed to investigate change in OnjisaponinB contents of Polygala tenuifolia depending on drying methods.
Methods and Results : For this study, 5-years-old Polygala tenuifolia local cultivars from RDA(Eumseong) were used. Before starting to drying, root was shade-dried for 3 days and separated with the lead. Next, two types of drying methods conducted; natural drying and hot air drying. Hot air drying was controlled at 40℃, 50℃, 60℃ and 70℃ and checked with every 3 hours. Dried root from market was used as control group. The water content of raw root was about 52.04%. When it started to dry, the contents of it significantly decreased. The dried roots from market were 6.25 - 6.84%. To be under 7% of water contents, 6 hours of drying was enough in natural drying methods and 40℃, 50℃hot air drying methods. In case of 60℃, 70℃ hot air drying methods, it took under 3 hours. The OnjisaponinB contents of raw root was 0.53%. The dried root from market had 0.74% of onjisaponinB. During the drying, the contents of OnjisaponinB changed depending on the drying methods. Hot air drying method had more effect on OnjisaponinB contents than natural drying method.
Conclusion : From the above results, we may suggest that natural drying methods was enough to drop the water content of Polygala tenuifolia. Because during pre-treatment steps including shade-drying and separating lead, much of water contents already decreased and became easy to lose water. However to get more OnjisaponinB, hot air drying methods can beneficial than natural drying methods.