Discrimination and Measurements of Three Flavonols with Similar Structure Using Terahertz Spectroscopy and Chemometrics

  • Ling Yan
  • Changhong Liu
  • Hao Qu
  • Wei Liu
  • Yan Zhang
  • Jianbo Yang
  • Lei Zheng


Terahertz (THz) technique, a recently developed spectral method, has been researched and used for the rapid discrimination and measurements of food compositions due to its low-energy and non-ionizing characteristics. In this study, THz spectroscopy combined with chemometrics has been utilized for qualitative and quantitative analysis of myricetin, quercetin, and kaempferol with concentrations of 0.025, 0.05, and 0.1 mg/mL. The qualitative discrimination was achieved by KNN, ELM, and RF models with the spectra pre-treatments. An excellent discrimination (100% CCR in the prediction set) could be achieved using the RF model. Furthermore, the quantitative analyses were performed by partial least square regression (PLSR) and least squares support vector machine (LS-SVM). Comparing to the PLSR models, the LS-SVM yielded better results with low RMSEP (0.0044, 0.0039, and 0.0048), higher Rp (0.9601, 0.9688, and 0.9359), and higher RPD (8.6272, 9.6333, and 7.9083) for myricetin, quercetin, and kaempferol, respectively. Our results demonstrate that THz spectroscopy technique is a powerful tool for identification of three flavonols with similar chemical structures and quantitative determination of their concentrations.


Flavonols Terahertz spectroscopy Qualitative identification Quantitative measurement Chemometrics 



This study is supported by the National Key Research and Development Plan of China (2016YFD0401104), the National Natural Science Foundation of China (31401544), the Funds for Huangshan Professorship of Hefei University of Technology (407-037019), the Key Science and Technology Specific Projects of Anhui Province (16030701078), and the Fundamental Research Funds for the Central Universities (JZ2016HGTB0712, JZ2017HGTB0195).

Supplementary material

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ESM 1 (DOCX 224 kb)


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.School of Food Science and EngineeringHefei University of TechnologyHefeiChina
  2. 2.School of Biological and Medical EngineeringHefei University of TechnologyHefeiChina
  3. 3.Intelligent Control and Compute Vision LabHefei UniversityHefeiChina
  4. 4.Hebei Food Inspection and Research Institute and Hebei Key Laboratory of Food SafetyShijiazhuangChina
  5. 5.Rice Research InstituteAnhui Academy of Agricultural SciencesHefeiChina

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