Rapid discrimination of geographical origin and evaluation of antioxidant activity of Salvia miltiorrhiza var. alba by Fourier transform near infrared spectroscopy

Radix Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li and Radix S. miltrorrhiza belong to the same genus. S. miltiorrhiza var. alba has a unique effectiveness for thromboangiitis besides therapeutical efficay of S. miltrorrhiza. It exhibits antioxidant activity (AA), while its quality and efficacy also vary with geographic locations. Therefore, a rapid and nondestructive method based on Fourier transform near infrared spectroscopy (FT-NIRS) was developed for discrimination of geographical origin and evaluation of AA of S. miltiorrhiza var. alba. The discrimination of geographical origin was achieved by using discriminant analysis and the accuracy was 100%. Partial least squares (PLS) regression was employed to establish the model for evaluation of AA by NIRS. The spectral regions were selected by interval PLS (i-PLS) method. Different pre-treated methods were compared for the spectral pre-processing. The final optimal results of PLS model showed that correlation coefficients in the calibration set (Rc) and the prediction set (Rp), root mean square error of prediction (RMSEP) and residual prediction deviation (RPD) were 0.974, 0.950, 0.163 mg mL(-1) and 2.66, respectively. The results demonstrated that NIRs combined with chemometric methods could be a rapid and nondestructive tool to discriminate geographical origin and evaluate AA of S. miltiorrhiza var. alba. The developed NIRS method might have a potential application to high-throughput screening of a great number of raw S. miltiorrhiza var. alba samples for AA.