Discrimination of liubao tea by FTIR and principal component analysis

To discriminate liubao tea from different storage years, explore the difference of chemical components and establish a rapid and non-destructive method for the discrimination of liubao tea from different storage years, fourier transform infrared spectroscopy (FTIR) combined with principal component analysis was utilized in this study. Liubao tea samples from five different storage years were collected for FTIR analysis, the raw infrared spectra of the samples were processed by the first derivative, the data was used to establish a discriminated model by means of principal component analysis, and the loading factors were extracted from the established model. As a result, discrimination of liubao tea from different storage years was observed in score plots. In the loading plot, it demonstrated that chemical discrimination of liubao tea from five different storage years was correlated to the contents of polyphenols, caffeine and amino acid. This study indicated that discrimination of liubao tea from five different years was achieved rapidly and non-destructively, and difference of chemical composition in different years could be characterized by the strategy of FTIR analysis combined with principal component analysis.