Rationale

AUTHOR=Zhang Ying , Jiang Kunxia , Chen Sisi , Wang Lina , Zhang Xun , Xu Wen , Yam Mun Fei , Wu Changhui , Xu Wei , Lin Yu TITLE=Quality control of Ganoderma lucidum by using C, H, O, and N stable isotopes and C and N contents for geographical traceability JOURNAL=Frontiers in Plant Science VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1234729 DOI=10.3389/fpls.2023.1234729 ISSN=1664-462X ABSTRACT=Rationale

Ganoderma lucidum (G. lucidum) 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 G. lucidum from different origins vary significantly; hence, fraudulent labeling is common. Reliable techniques for G. lucidum 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 G. lucidum.

Methods

G. lucidum samples from various sources and in varying stages were identified by using δ¹³C, δD, δ¹⁸O, δ¹⁵N, 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 G. lucidum from various sources or track various stages of G. lucidum.

Results

In the stage model, the δ¹³C, δD, δ¹⁸O, δ¹⁵N, C, and N contents were considered meaningful variables to identify various stages of G. lucidum (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 (δ¹³C, δD, δ¹⁸O, and δ¹⁵N). In the origin model, only four variables, namely δ¹³C, δD, δ¹⁸O, and δ¹⁵N, were used. PCA divided G. lucidum 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 G. lucidum. The model was validated by other test samples (Pseudostellaria heterophylla), and the external test (G. lucidum) 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 G. lucidum, providing a promising method to identify stages of G. lucidum.