Abstract:

Near infrared spectroscopy(NIRS) was developed as a rapid analysis method for the qualitative and quantitative assessment of the quality of red ginseng. Discriminant analysis(DA) based on principal component analysis and Mahalanobis distance was used to distinguish red ginseng from counterfeits non-destructively. The result shows that the proposed method could distinguish red ginseng from counterfeits correctly and no misclassified sample was found in both training and test sets. The partial least squares(PLS) algorithm was used to predict the sum of ginsenosides Re and Rg1 and the content of ginsenoside Rb1. Two calibration models were developed to correlate NIR spectra with the reference values determined by HPLC method. The correlation coefficient(R), the root mean square error of calibration(RMSEC) and the root mean square error of prediction(RMSEP) were as follows: R=0.9827, RMSEC=0.0163%, RMSEP=0.0250% for the sum of ginsenosides Re and Rg₁; R=0.9869, RMSEC=0.0156%, RMSEP=0.0256% for content of ginsenoside Rb₁. The overall results demonstrate that NIRS coupled with chemometrics could be successfully applied as a rapid, precise and cost-effective method not only to identify the red ginseng from counterfeits but also to determine simultaneously some chemical compositions in red ginseng.

Key words: Near infrared spectroscopy; Red ginseng; Discriminant analysis; Partial least squares