[Rapid evaluation of frying degree of Ziziphi Spinosae Semen based on spectrophotometry and near-infrared spectroscopy combined with multivariate mathematical statistics].
摘要
To rapidly evaluate Ziziphi Spinosae Semen samples with different frying degrees, this study employed a CM-5 spectrophotometer to detect the dynamic color changes during the frying process. Near-infrared spectroscopy was utilized to measure Ziziphi Spinosae Semen samples at different frying degrees via diffuse reflectance. Principal component analysis(PCA), partial least squares discriminant analysis(PLS-DA), and orthogonal partial least squares discriminant analysis(OPLS-DA) were combined to quickly assess the quality of Ziziphi Spinosae Semen at different frying degrees. The results showed that with prolonged frying time, the brightness of Ziziphi Spinosae Semen decreased slightly, while the red and yellow hues became more pronounced, and color saturation increased. The saturation value(C~*), yellow-blue value(b~*), and red-green value(a~*) were the primary variables contributing to the color difference between raw and fried Ziziphi Spinosae Semen. The OPLS-DA model was employed to distinguish between raw and fried Ziziphi Spinosae Semen based on color parameters. The near-infrared raw spectra of Ziziphi Spinosae Semen samples with varying frying degrees were pretreated and optimized using multiple scatter correction(MSC) and competitive adaptive reweighted sampling(CARS). The PLS-DA model effectively differentiated samples with different frying degrees. The R~2 values for both the calibration and prediction sets of the discrimination model were greater than 0.90, indicating good discriminative capability. This study achieved rapid evaluation of different frying degrees of Ziziphi Spinosae Semen decoction pieces and provides a scientific reference for quality control during the processing of fried Ziziphi Spinosae Semen decoction pieces.