Rapid detection of talcum powder in tea using FT-IR spectroscopy coupled with chemometrics

Abstract

This paper investigated the feasibility of Fourier transform infrared transmission (FT-IR) spectroscopy to detect talcum powder illegally added in tea based on chemometric methods. Firstly, 210 samples of tea powder with 13 dose levels of talcum powder were prepared for FT-IR spectra acquirement. In order to highlight the slight variations in FT-IR spectra, smoothing, normalize and standard normal variate (SNV) were employed to preprocess the raw spectra. Among them, SNV preprocessing had the best performance with high correlation of prediction (RP = 0.948) and low root mean square error of prediction (RMSEP = 0.108) of partial least squares (PLS) model. Then 18 characteristic wavenumbers were selected based on a hybrid of backward interval partial least squares (biPLS) regression, competitive adaptive reweighted sampling (CARS) algorithm and successive projections algorithm (SPA). These characteristic wavenumbers only accounted for 0.64% of the full wavenumbers. Following that, 18 characteristic wavenumbers were used to build linear and nonlinear determination models by PLS regression and extreme learning machine (ELM), respectively. The optimal model with RP = 0.963 and RMSEP = 0.137 was achieved by ELM algorithm. These results demonstrated that FT-IR spectroscopy with chemometrics could be used successfully to detect talcum powder in tea.

Fourier Transform Infrared and Raman and Hyperspectral Imaging Techniques for Quality Determinations of Powdery Foods: A Review

“…Consequently, another study further verified that the selection of the proper spectral variables based on biPLSR can enhance the performance of other models. Li and others () investigated the possibility of FT‐MIR (4000 to 400 cm −1 ) to quantify talcum powder contamination in tea powder. Based on a hybrid of biPLSR, competitive adaptive reweighted sampling (CARS), and SPA, a group of 18 characteristic variables (914, 1011, 1016, 1021, 1035, 1050, 1059, 1067, 1080, 1182, 1249, 1340, 1613, 1631, 1683, 1804, 2296, and 2370 cm −1 ) was chosen as the most informative wavenumbers.…”

Emerging techniques for determining the quality and safety of tea products: A review

“…However, because talc is a natural ore, unfiltered natural talcum powder may contain asbestos, which can be dangerous to humans if it enters the lungs, and is not suitable for direct use. Using FT‐IR spectroscopy coupled with chemometrics to perform qualitative and quantitative detections of talcum powder added to commercial tea, not only achieved the predicted results of R 2 P of 0.927 and RMSEP of 0.137 (Li, Zhang, & He, 2016), but also provided guidance of the rapid detection of talcum powder in other foods, medicine, and cosmetics, revealing the application potential of FT‐IR spectroscopy in the evaluation of talcum powder adulteration.…”

“…Ultraviolet–visible spectroscopy (UV‐vis) (Diniz, Barbosa, De Melo Milanez, Pistonesi, & De Araújo, 2016; Yu & He, 2018), near‐infrared spectroscopy (Chen, Zhao, Zhang, & Wang, 2006, 2007; Zhao, Chen, Huang, & Fang, 2006), Fourier transform infrared (FT‐IR) spectroscopy (Li, Sun, Luo, & He, 2015, 2016), Raman spectroscopy (Li et al., 2015; Zhang et al., 2020), laser‐induced breakdown spectroscopy (LIBS) (Yu, Peng, Liu, & He, 2017), and terahertz (Chen, Cao, & Liu, 2011) in spectroscopic techniques, electric nose (E‐nose) (Chen, Liu, Zhao, & Ouyang, 2013; Dutta, Hines, Gardner, Kashwan, & Bhuyan, 2003), electric tongue (E‐tongue) (Zhi, Zhao, & Zhang, 2017), electric eye (E‐eye) (Xu, Wang, & Zhu, 2019), adsorptive stripping voltammetry (ASV) (Guo, Zheng, Mo, & Ye, 2009), cyclic voltammetry (CV) (Kilmartin & Hsu, 2003; Liu et al., 2014), square‐wave voltammetry (SWV) (Novak, Šeruga, & Komorsky‐Lovrić, 2010), and capillary zone electrophoresis (Horie, Mukai, & Kohata, 1997) in electrochemical methods, nanozymes (Wang, Liu, Qin, Chen, & Shen, 2016; Zhang & Huang, 2015), computer vision (Wang et al., 2015; Xu, Wang, & Gu, 2019; Ye et al., 2019), and modified chromatographic techniques are the five main emerging techniques for quality and safety evaluation of tea products, determining parameters qualitatively and quantitatively, with their distinct advantages and disadvantages, as well as suitable but different detection target. To the best of our knowledge, no study has reviewed the applications of these emerging techniques for the evaluation of different parameters in tea products.…”

Assessment of ATR‐NIR and ATR‐MIR spectroscopy as an analytical tool for the quantification of the total polyphenols in Dendrobium huoshanense

“…As rapid, green, non‐destructive and low‐cost analytical techniques, attenuated total reflectance near‐infrared (ATR‐NIR) spectroscopy and attenuated total reflectance mid‐infrared (ATR‐MIR) spectroscopy are emerging powerful techniques for analyses of chemical components in complex herbs . Most commonly, ATR‐NIR spectra (ca.…”