Simultaneous Volatile Aroma Compounds and Ginsenosides for the Geographical Origin of American Ginseng (Panax Quinquefolius L.)

Abstract

ABSTRACT:  American ginseng ( Panax quinquefolius L.) is protected by Geographical Indications as harvested roots have different regional characteristics. The aim of this study was to distinguish 95 American ginseng samples from four origins (including America, Canada, Shandong province and the Northeast provinces in China), and to further discriminate samples harvested within the protected designation of origin (PDO) from those harvested in non-PDO regions. Two metabolomic methods in combination with chemometrics were used to acquire qualitative data on the metabolites of American ginseng samples from different origins, namely high-performance liquid chromatography (HPLC) and headspace-gas chromatography-mass spectrometry (HS-GC-MS). There were significant differences in numerous metabolites, including volatile compounds and ginsenosides. American ginsengs from four different regions were discriminated based on 25 volatile compounds and 8 ginsenosides using linear discriminant analysis (LDA), which had a 96.8% accuracy and a 74.7% cross validation rate, and random forest (RF) modeling, which reached 100% accuracy using the training set and 92.9% accuracy using the testing set. The same 33 analytes combined with different pattern recognition were compared for discrimination of PDO and non-PDO samples. The best accuracy was again obtained using the RF model, but only when using data from both HS-GC-MS and HPLC. The addition of aroma and saponin fingerprints significantly improved the accuracy of discriminating PDO from non-PDO samples. The result indicated that it is better to incorporate different technologies rather than relying on a single technology.

Keywords: KEYWORDS: Panax quinquefolius, geographical origin, volatile compounds, ginsenosides, multivariate statistical analysis.