Quality control of by using C, H, O, and N stable isotopes and C and N contents for geographical traceability.

RATIONALE

() is a popular medicinal fungus that has been used in traditional medicine for decades, with its provenance influencing its medicinal and commercial worth. The amount of active ingredients and the price of from different origins vary significantly; hence, fraudulent labeling is common. Reliable techniques for geographic verification are urgently required to safeguard the interests of consumers, producers, and honest dealers. A stable isotope is widely acknowledged as a useful traceability technique and could be developed to confirm the geographical origin of .

METHODS

samples from various sources and in varying stages were identified by using C, D, O, N, C, and N contents combined with chemometric tools. Chemometric approaches, including PCA, OPLS-DA, PLS, and FLDA models, were applied to the obtained data. The established models were used to trace the origin of from various sources or track various stages of .

RESULTS

In the stage model, the C, D, O, N, C, and N contents were considered meaningful variables to identify various stages of (bud development, growth, and maturing) using PCA and OPLS-DA and the findings were validated by the PLS model rather than by only four variables ( C, D, O, and N). In the origin model, only four variables, namely C, D, O, and N, were used. PCA divided samples into four clusters: A (Zhejiang), B (Anhui), C (Jilin), and D (Fujian). The OPLS-DA model could be used to classify the origin of . The model was validated by other test samples (), and the external test () by PLS and FLDA models demonstrated external verification accuracy of up to 100%.

CONCLUSION

C, H, O, and N stable isotopes and C and N contents combined with chemometric techniques demonstrated considerable potential in the geographic authentication of , providing a promising method to identify stages of .