A chemometric modeling-free near infrared barcode strategy for smart authentication and geographical origin discrimination of Chinese ginseng

Abstract

With the growing interest in alternative medicine, handy identification and differentiation of herbal medicines are becoming increasingly important. Here we report a chemometric modeling-free near infrared (NIR) barcode strategy for the smart identification and geographical origin discrimination of Chinese ginseng. The novel strategy demands the transformation of Chinese ginseng (standard and sample) NIR spectra into a barcode representation through assigning zero intensity to every NIR peak except the peaks having intensities greater than average peak intensity. Meanwhile, for Chinese ginseng standard NIR barcode, barcoding condition such as padding size was carefully optimized. It has been demonstrated that the padding size for each bar in the barcode is 8 cm^-1. By comparing the percentage of nonzero overlap between Chinese ginseng standard barcode and sample barcodes, eight batches of samples (including Chinese ginseng, American ginseng and counterfeit) were successfully identified with 100% accuracy, respectively. Interestingly, the discrimination of the origin of ginsengs from three provinces (Jilin, Liaoning and Heilongjiang) of Northeastern China was achieved utilizing NIR barcode method. Two characteristic bars at 7750 and 8250 cm^-1 were inspected in the ginseng sample from Jilin province, two specific bars at 6780 and 7015 cm^-1 were displayed in the ginseng sample from Liaoning province and three distinct bars at 6560, 6910 and 7995 cm^-1 were monitored in the ginseng sample from Heilongjiang province. The results indicate that the proposed method will be greatly expanded and applied as an inspecting platform for the on-site analysis and valid identification of Chinese ginseng in herbal markets by a handheld spectrometer or barcode scanner.

Keywords: Authentication; Barcode; Chinese ginseng; Discrimination; Near infrared.