ATR-FTIR spectroscopy combined with chemometrics to assess the spectral markers of irradiated baijius and their potential application in irradiation dose control

Rui Zhou; Xiaoming Chen; Min Huang; Hao Chen; Lili Zhang; Defu Xu; Dan Wang; Peng Gao; Bensheng Wang; Xiaoxue Dai

doi:10.1016/j.saa.2023.123162

ATR-FTIR spectroscopy combined with chemometrics to assess the spectral markers of irradiated baijius and their potential application in irradiation dose control

Spectrochim Acta A Mol Biomol Spectrosc. 2023 Dec 5:302:123162. doi: 10.1016/j.saa.2023.123162. Epub 2023 Jul 17.

Authors

Rui Zhou¹, Xiaoming Chen², Min Huang³, Hao Chen³, Lili Zhang¹, Defu Xu⁴, Dan Wang¹, Peng Gao³, Bensheng Wang¹, Xiaoxue Dai⁴

Affiliations

¹ College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, PR China.
² College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, PR China. Electronic address: cxmxkd@163.com.
³ Sichuan Institute of Atomic Energy, Chengdu 610101, Sichuan, PR China.
⁴ Luzhou Laojiao Co., Ltd, Luzhou 646699, Sichuan, PR China.

PMID: 37478760
DOI: 10.1016/j.saa.2023.123162

Abstract

Although some methods have been proposed for the identification of irradiated baijius, they are often costly, time-consuming, and destructive. It is also unclear what instrumentation can be used to fully characterize the quality changes in irradiated baijius. To address this issue, this study pioneers the use of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy in combination with chemometrics to open up new avenues for characterizing irradiated baijius and their quality control. Principal component analysis, five spectral pre-processing methods (Savitzky-Golay smoothing (S-G), second-order derivative (SD), multiple scattering correction (MSC), S-G + SD and S-G + MSC), five wavelength selection methods (random forest variable importance (RFVI), two-dimensional correlation spectroscopy (2D-COS), variable importance in projection (VIP), ReliefF, and Venn), and three classification models (partial least squares-discriminant analysis (PLS-DA), random forest (RF), and grasshopper optimization algorithm-based support vector machine (GOA-SVM)) were integrated into the analytical framework of ATR-FTIR spectroscopy, aiming to accurately identify baijiu samples according to different irradiation doses and to search for irradiation-induced spectral difference characteristics (spectral markers). The results showed that SD was the best spectral pre-processing method, and RF models constructed using the 20 most competitive and discriminative spectral markers (selected by Venn) could achieve accurate identification of baijiu samples based on irradiation dose (0, 4, 6, and 8 kGy). After Pearson correlation analysis, the five significantly (P＜0.05) changed spectral markers (1596, 2025, 2309, 2329, and 2380 cm^-1) were attributed to changes in the content of total acids, alcohols, and aromatic compounds. These findings demonstrate for the first time the potential of ATR-FTIR spectroscopy as a fast, low-cost, and non-destructive tool for the characterization and identification of irradiated baijiu samples. This approach may also offer a promising solution for labeling management of irradiated foods, vintage identification of baijius, and brand protection.

Keywords: ATR-FTIR; Chemometric; Classification model; Irradiation modification; Nongxiangxing Baijiu; Wavelength selection.

MeSH terms

Algorithms*
Chemometrics*
Discriminant Analysis
Least-Squares Analysis
Principal Component Analysis
Spectroscopy, Fourier Transform Infrared / methods