Increment of Ginsenoside Accumulation in Ginseng Rhizome Joints and the Prediction of the Growth Year

ABSTRACT Introduction The growth year of ginseng is relevant to its quality and commercial value. Ginseng rhizome joint number increases by growth year. The relationship between the metabolite accumulation and the growth year of a rhizome remains unclear. Most forest‐grown ginseng rhizomes can conveniently be separated into different joints and are suitable materials for investigating ginseng metabolite accumulation. Objectives This work aims to elucidate how ginsenoside accumulates in the ginseng rhizome joint and if it is applicable for growth‐year determination. Methods Forest‐grown Panax ginseng rhizomes were separated into different joints according to their growth scars; ginsenosides in each joint were then tested using high‐performance liquid chromatography–tandem mass spectrometry. The age‐related ginsenosides screening was performed using orthogonal partial least squares analysis (OPLS). Several ground‐cultivated ginseng rhizomes have also been tested. Results Ginsenoside contents in different joints of a rhizome increase with its growth year and reach their corresponding equilibriums in specific years. Notoginsenoside R3 and ginsenoside Rg1 were the most relevant to the growth year. They increase continuously from 0 to 8 years. Perhaps, the OPLS improved the linearity of the relationship between scores and ages. The predictions of the growth year of a rhizome joint using the OPLS models were accurate. Conclusion Some ginsenosides increased in ginseng rhizome joints by their growth year. The OPLS score of a rhizome joint can be used to determine its growth year.