[Technological parameter optimization method for washing of coarse bear gall powder extracts based on NIR spectroscopy].

During the washing process of coarse bear gall powder extracts, it is necessary to adjust the amount of ethyl acetate according to the properties of raw materials, which aims to improving the yield and purity of the final product. In the research, using NIR spectra to reflect the comprehensive properties of coarse bear gall powder extracts, the process is optimized in a flexible way. Forty batches experiments are designed according to the weight ratio of ethyl acetate and coarse extracts of bear gall powder. The NIR spectra of the coarse extracts of bear gall powder are collected and processed using principal component analysis (PCA) method. The first 8 principal components combined with the amount of the ethyl acetate are used as the input variables, and calibration models are established to predict the yield and purity of the final product 30 batches are used as calibration set, which is used to establish the models, and other 10 batches are used as validation set, which is used for the performance appraisal of the established models. The correlation coefficients of the calibration, inner cross-validation and external validation for the purity model are 0.902, 0.896 and 0.883, respectively, and the RMSEC, RMSECV and RMSEP are 1.22%, 1.48% and 1.59%, respectively. The correlation coefficients of the calibration, inner cross-validation and external validation for the yield model are 0.921, 0.859 and 0.916, respectively, and the RMSEC, RMSECV and RMSEP are 1.39%, 1.65% and 1.53% respectively. This work demonstrated that NIR spectra combined with technology parameter could be used to predict the yield and purity of the final product. Using the established models, the most appropriate amount of the ethyl acetate can be determined according to the properties of the coarse bear gall powder extracts, and the yield and purity of the final product can be improved.