Quality Degradation of Chinese White Lotus Seeds Caused by Dampening during Processing and Storage: Rapid and Nondestructive Discrimination Using Near-Infrared Spectroscopy

Abstract

Dampening during processing or storage can largely influence the quality of white lotus seeds (WLS). This paper investigated the feasibility of using near-infrared (NIR) spectroscopy and chemometrics for rapid and nondestructive discrimination of the dampened WLS. Regular (n = 167) and dampened (n = 118) WLS objects were collected from five main producing areas and NIR reflectance spectra (4000–12000 cm−1) were measured for bare kernels. The influence of spectral preprocessing methods, including smoothing, taking second-order derivatives (D2), and standard normal variate (SNV), on partial least squares discrimination analysis (PLSDA) was compared to select the optimal data preprocessing method. A moving-window strategy was combined with PLSDA (MWPLSDA) to select the most informative wavelength intervals for classification. Based on the selected spectral ranges, the sensitivity, specificity, and accuracy were 0.927, 0.950, and 0.937 for SNV-MWPLSDA, respectively.

Rapid Recognition of Geoherbalism and Authenticity of a Chinese Herb by Data Fusion of Near-Infrared Spectroscopy (NIR) and Mid-Infrared (MIR) Spectroscopy Combined with Chemometrics

“…From another aspect, as a powerful pattern recognition method, PLSDA has successfully been applied to solve classification problems in many scientific fields [27,28]. Furthermore, a global model with moving window partial least-squares (MWPLS) [29,30] like other variable selection methods, MWPLSDA was successfully applied to spectra interval selection for calibration problems, and desirable results were obtained [31]. A subset of the whole wavelengths to develop the calibration model, the wavelengths carrying serious heteroscedastic noises, and especially the spectral ranges contaminated by external factors are excluded from the model, and wavelength ranges sensitive only to the chemical compositions of the samples are selected to develop a simplified yet stable calibration model.…”