Rapid Determination of Lycium Barbarum Polysaccharide with Effective Wavelength Selection Using Near-Infrared Diffuse Reflectance Spectroscopy

A rapid method to evaluate the amount of Lycium barbarum polysaccharides (LBPs) based on near-infrared diffuse reflectance spectroscopy (NIDRS) is proposed. A total of 114 dried L. barbarum samples from different regions of China were used for modeling by partial least squares (PLS) regression with the effective wavelengths (EWs) selected by correlation coefficients and X-loading weights. The PLS model worked best with EWs of 4003–5087, 5568–7002, and 7463–12,000 cm−1. These EWs were chosen by correlation coefficients after spectral pretreatment. Use of these EWs resulted in determination coefficients of calibration and validation of 0.982 and 0.938, respectively. The proposed model successfully predicted external samples, which further confirmed prediction ability of the model. Overall results indicated that both correlation coefficients and X-loading weights for EWs selection can improve model performance and that NIDRS can rapidly determine LBPs with intact particle samples.