Ginsenoside composition changes in ginseng extracts by different ascorbic acid treatments

Abstract

The purpose of this study was to develop a new preparation process for chemical transformation of ginseng saponin glycosides to prosapogenins. Ginseng and ginseng extracts were processed under several treatment conditions using ascorbic acid solution. Treating with ascorbic acid at pH 2-3 and above 80 degrees C increased the ginsenoside Rg(3) content of samples to over 3% as compared to other pH levels and temperatures. In addition, ginseng and ginseng extracts that were processed under a high ascorbic acid solution treatment condition (pH 2.0, 5 hr) contained more ginsenoside Rg(3) (approximately 16 times) than those processed under a low ascorbic acid solution treatment condition (pH 3.0, 5 hr). The highest quantity of ginsenoside Rg(3) (3.434%) occurred when a sample of fine ginseng root extract (AG2-9) was processed with the ascorbic acid solution at pH 2.0 for 9 hr. However, there was no change in the amount of ginsenoside Rg(3) when fine ginseng root extracts were processed with ascorbic acid solution at pH 2.0 for over 9 fir. In conclusion, the results indicated that ascorbic acid treatment of ginseng extracts can produce a level of ginsenoside Rg(3) that is over 90-fold the amount found in commercial red ginseng.