RAPID DETECTION OF EXOGENOUS ADULTERANTS AND SPECIES DISCRIMINATION FOR A CHINESE FUNCTIONAL TEA (BANLANGEN) BY FOURIER-TRANSFORM NEAR-INFRARED(FT-NIR) SPECTROSCOPY AND CHEMOMETRICS

摘要

The practical adulterations of herbal tea are usually performed by adding somernmarker components together with adulterants, or some exogenous adulterantsrncontaining the marker components. It is difficult to detect such adulterations byrnthe traditional analytical methods focused on a few marker components. Therefore,rnFourier-transform near-infrared (FT-NIR) spectroscopy was used to characterizernthe compositions and class models of authentic banlangen tea and to detectrnpossible exogenous adulterants. Discrimination of two different species ofrnbanlangen tea was also performed using partial least squares discrimination analysisrn(PLSDA). The most accurate one-class partial least squares (OCPLS) modelrnwas obtained with standard normal variate (SNV) transformation. SNV-OCPLSrncould detect adulterations with 5% (w/w) or more dried apple skin in banlangen.rnFor species discrimination, a total classification accuracy of 0.936 was achieved byrnSNV-PLSDA. FT-NIR spectrometry and chemometrics can provide a useful andrnalternative tool for rapid quality control of banlangen tea.