Change of ginsenoside composition in red ginseng processed with citric acid

The purpose of this research was to investigate the composition of ginsenosides and to identify the chemical structures of ginsenosides generated from red ginseng by citric acid pre-treatment (RGC). The amount and the composition of ginsenosides in red ginseng (RG) and RGC were determined by high performance liquid chromatography (HPLC) analysis. The content of Rg₃, a well-known bioactive ginsenoside in RGC increased significantly (p<0.05) over 2 fold (0.411 mg/g) when compared with RG (0.186 mg/g). Moreover, the structures of 5 novel ginsenosides in RGC were investigated by liquid chromatography/mass spectrometry (LC/MS/MS) analysis. Three peaks were completely fragmentized from their mother ions to aglycones and suggested to be less polar ginsenosides Rk₃/Rh₄, Rk₁, and Rg₅. This study suggested that by processing red ginseng with citric acid it is possible to enhance the yield of both ginsenoside Rg₃ and less polar ginsenosides.