Identification of curcumin content in raw and vinegar-processed rhizomes of Curcuma kwangsiensis based on electronic nose combined with back propagation neural network / 中国中药杂志

This study aimed to establish a rapid and accurate method for identification of raw and vinegar-processed rhizomes of Curcuma kwangsiensis, in order to predict the content of curcumin compounds for scientific evaluation. A complete set of bionics recognition mode was adopted. The digital odor signal of raw and vinegar-processed rhizomes of Curcuma kwangsiensis were obtained by e-nose, and analyzed by back propagation(BP) neural network algorithm, with the accuracy, the sensitivity and specificity in discriminant model, correlation coefficient as well as the mean square error in regression model as the evaluation indexes. The experimental results showed that the three indexes of the e-nose signal discrimination model established by the neural network algorithm were 100% in training set, correction set and prediction set, which were obviously better than the traditional decision tree, naive bayes, support vector machine, K nearest neighbor and boost classification, and could accurately differentiate the raw and vinegar products. Correlation coefficient and mean square error of the regression model in prediction set were 0.974 8 and 0.117 5 respectively, and could well predict curcumin compounds content in Curcuma kwangsiensis, and demonstrate the superiority of the simulation biometrics model in the analysis of traditional Chinese medicine. By BP neural network algorithm, e-nose odor fingerprint could quickly, conveniently and accurately realize the discrimination and regression, which suggested that more bionics information acquisition and identification patterns could be combined in the field of traditional Chinese medicine, so as to provide ideas and methods for the rapid evaluation and stan-dardization of the quality of traditional Chinese medicine.

Correlation Between Effective Constituent Content and Color During Fermentation of Polygonati Rhizoma / 中国实验方剂学杂志

Objective:To explore the correlation between effective constituent content and external color by measuring the chroma value and the content of polysaccharide，saponin and lovastatin during the fermentation of Polygonati Rhizoma samples， in order to provide reference for the quality control of Monascus fermented Polygonati Rhizoma. Method:Polygonati Rhizoma was inoculated with Monascus for solid-state fermentation，and the content of polysaccharide and saponin was determined by colorimetric method， while the content of lovastatin，a new ingredient after fermentation，was determined by HPLC. The chroma values L*，a*，b* of all these samples were measured by a color difference meter. SPSS 20.0 was used to analyze the correlation and regression between component content and chroma value，and the differences between samples in the fermentation process was studied through multi-dimensional scale analysis and cluster analysis. Result:With the prolongation of fermentation time，the content of polysaccharide gradually increased to the peak value on day 9， and then gradually decreased. The content of saponin showed an rising trend in general，with slight fluctuations in the middle. Lovastatin levels peaked on day 15， and fell sharply since then. The content of polysaccharide was positively related to the lightness value L* and the total color value E*ab （P<0.01），and the contents of saponin and lovastatin were significantly related to the red-green value a*（P<0.01）. The results of regression analysis showed that 52.8% of the change in lightness value L* was affected by the content of polysaccharide，saponin and lovastatin，and the saponin content could be predicted by a* and L* to the extent of 54.1%，while the lovastatin content can be predicted by a* to the extent of 61.7%. The determination coefficient of the polysaccharide regression model was less than 0.4，so the polysaccharide content could not be predicted based on the chroma value. Through the multi-dimensional scale analysis and cluster analysis，the samples were divided into four categories according to fermentation time： 0-3，3-7，7-11，11-18 d. Conclusion:The fermentation of Monascus and Polygonati Rhizoma can lead to the change of effective constituent and appearance color of the latter，which provides the basis for the fermentation process of Polygonati Rhizoma. In addition， the content of saponin and lovastatin can be predicted by the chroma value of fermented Polygonati Rhizoma to a certain extent，which provides a simple and fast inspection method for the dynamic monitoring of effective constituent content in fermented Polygonati Rhizoma.