Discrimination of the Geographical Origin of Chinese Chestnut Based on Stable Isotope and Rare Earth Element Fingerprint Characteristics

Abstract

In order to protect the geographical origin information of Chinese chestnut as a geographical indication product, 164 Chinese chestnut samples were collected from 10 provinces, including Qianxi in Hebei, Jixian in Tianjin and Huairou in Beijing for analysis of stable isotopes (C, H, O, and N) and mineral elements using elemental analysis-stable isotope mass spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). Analysis of variance (ANOVA), principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to classify the production regions of Chinese chestnut and establish a geographical origin traceability model. The results showed that the cross-validation rate of the OPLS-DA model for the 10 geographical origins was 100%, and the area of the receiver operating characteristic (ROC) curve was close to 1. The elements Mg, δ2H, δ18O, Al, Na, δ15N, Cu, Ba, Zn and Th were the main factors (variable importance in the projection, VIP > 1) to distinguish Hebei chestnuts and those from the other nine production regions. The established model can provide an effective theoretical basis for geographical origin discrimination of Chinese chestnut.

Keywords

• chinese chestnut; traceability; stable isotopes; mineral elements; chemometrics