title: Optimization of informative spectral variables for the quantification of EGCG in green tea using Fourier transform near-infrared (FT-NIR) spectroscopy and multivariate calibration.
abstract: Epigallocatechin-3-gallate (EGCG) is credited with the majority of the health benefits associated with green tea consumption. It has a high economic and medicinal value. The feasibility of using different variable selection approaches in Fourier transform near-infrared (FT-NIR) spectroscopy for a rapid and conclusive quantitative determination of EGCG in green tea was investigated. Graphically oriented multivariate calibration modeling procedures such as interval partial least squares (iPLS), synergy interval partial least squares (siPLS), and genetic algorithm optimization combined with siPLS (siPLS-GA) were applied to select the most efficient spectral variables that provided the lowest prediction error. The performance of the final model was evaluated according to the root mean square error of prediction (RMSEP) and coefficient of determination (R(2)) for the prediction set. Experimental results showed that the siPLS-GA model obtained the best results in comparison to other models. The optimal models were achieved with R(2)(p) = 0.97 and RMSEP = 0.32. The model can be obtained with only 36 variables retained and it provides a robust model with good estimation accuracy. This demonstrates the potential of NIR spectroscopy with multivariate calibration methods to quickly detect the bioactive component in green tea.
authors.affiliation: National Engineering Research Center for Information Technologies in Agriculture, Beijing 100097, China. guozm@nercita.org.cn
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Guo
authors.forename: Quansheng
authors.initials: Q
authors.lastname: Chen
authors.forename: Liping
authors.initials: L
authors.lastname: Chen
authors.forename: Wenqian
authors.initials: W
authors.lastname: Huang
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.forename: Chunjiang
authors.initials: C
authors.lastname: Zhao
mesh_terms: D000465:Algorithms; D002138:Calibration; D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate