Geographical origin and species identification of lilii bulbus using C/N/H/O stable isotopes and multi-elemental combined chemometrics

Abstract

Lilii bulbus is an important food in China with medicinal and edible functions, and its quality and price are closely related to its geographical origin. In this work, 4 stable isotopes (δ13C, δ15N, δ2H and δ18O) and 41 mineral elements of lilii bulbus samples from 11 origins and 4 species were collected and combined with chemometrics to identify origins and species. ANOVA and principal component analysis (PCA) showed significant differences (P < 0.05) in stable isotopes and multiple elements in lilii bulbus samples from different origins, and Cu, Zn, K, δ18O, Sr and Li are important contributors to the classification. Partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to classify different species of lilii bulbus with good classification performance, while indicating that K, Ca, Na and Mg elements could be used as effective elements for species classification. The external validation model of OPLS-DA showed high accuracy (>89%) for lilii bulbus species classification. This study shows that stable isotopes and multi-elemental combined chemometrics provide an effective method for lilii bulbus origin and species identification.