Feasibility study on quantitative analysis of total catechins in tea polyphenol powder by near-infrared spectroscopy
CHEN Hua-cai~(1,2), LV Jin~3, FENG Chun-hong~4, LU Yong-jun~2, CHEN Xing-dan~2(1. College of Life Sciences of China Jiliang University, Hangzhou, 310018, China;2. State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics,Chinese Academy of Sciences, Changchun 130033, China; 3. College of Metrological Technology & Engineering of China Jiliang University, Hangzhou 310018, China; 4. Tea Research Institute of Chinese Academy of Agricultural Sciences, Hangzhou 310008, China)
This paper indicates the possibility to use near infrared spectroscopy (NIRS) combined with PLS as a rapid method to determine the content of total catechins in tea polyphenol (TP) powder. Reference values of total catechins of 48 TP powder samples were analyzed by HPLC. PLS calibration models were built with diffuse reflectance spectra in 1 000~2 500 nm region after pre-processed with first derivative, second derivative, standard normal variate (SNV), and multiplicative signal correction (MSC) respectively. Results indicated that the calibration model built with PLS after spectra pre-processed with SNV was the best. The correlation coefficient and RMSEC of this model were 0.997 and 1.71 % respectively. The comparison of the calibration models built with CLS, PLS and PCR indicated that the PLS was the optimal method.