Accurate origin identification of Chinese white Chrysanthemi Flos by analysis of C, N, O, H stable isotope ratios and mineral elements combined with chemometrics

Abstract

Chrysanthemum is a common medicinal and edible Chinese herbal product, and its growth environment affects its quality and market sale price. So it has high practical value and relevance to establish an efficient, rapid and accurate approach to identify the origin of chrysanthemums. In this study, we collected chrysanthemum samples from six geographical indication (GI) production areas in China and analyzed the four stable isotope ratios (δ13C, δ15N, δ18O, and δ2H) and 44 mineral element signatures of chrysanthemums to classify chrysanthemum. An analysis of variance (ANVOA) indicated that stable isotope ratios and mineral elements differed significantly between origins. The accuracies of the training set and prediction set of the random forest (RF) algorithm were 100% and 98.3%, respectively, while those of the partial least squares discriminant algorithm (PLS-DA) were 96.9% and 96.7%, respectively; the results of the RF algorithm were slightly better than those of the PLS-DA. Combining stable isotopes and mineral elements could enhance the accuracy of origin identification. Moreover, the OPLS-DA (orthogonal partial least squares discriminant analysis) models for stable isotopes and mineral elements indicated that δ2H, δ18O, Cd, Zn, Mg, Ca, Tm, As, and Tl were the elements that could most effectively distinguish the origins of chrysanthemum, and the discriminant accuracy reached 100%. Therefore, the proposed strategy can offer a simple, rapid, and dependable approach for classifying the geographic origin of chrysanthemums.