Metal-Phytochemical Synergy: Quality Enhancement of Gastrodia elata Guided by Elemental Fingerprinting
Yongjun Peng, Yiru Zhao, Junxian Li, Xiaoyu Fu, Jiajing Yu, Xingguo Zhang, Weizhen Fang, Hezhong JiangObjective:
Gastrodia elata is a valued medicinal–edible plant, yet concerns about its longterm food safety and the challenges of cultivation limit its further development. This study evaluated the elemental profiles, heavy-metal safety, and antioxidant capacity of G. elata from 14 geographic origins to identify elements associated with quality enhancement.
Methods:
The contents of 25 metal elements, gastrodin, and total phenolics were determined by ICPMS and HPLC-UV. Multivariate analyses (PCA, HCA) revealed clustering patterns. Heavy metal safety was assessed against the strictest regulatory limits from China, the United States, Japan, and Europe. Key quality-related elements were screened via the Mantel test, and in vitro antioxidant capacity (ABTS, hydroxyl, and DPPH radical scavenging) was measured.
Results:
G. elata contained abundant essential trace elements; the elemental profiles were highly conserved, while concentrations varied across regions. Nine of the 14 samples (64.3%) were classified as safe/clean, one as alert, three as mildly contaminated, and one (TM-4) as moderately contaminated; the elevated classification of TM-4 was solely attributable to its high Cu content (66.999 mg/kg), whereas total heavy metal content in all other samples was less than 20 mg/kg. Magnesium (Mg) and titanium (Ti) showed significant positive correlations with total phenolic content. TM-1 exhibited the highest gastrodin content (209.41 μg/mL); TM-2, the highest total phenolics (0.206 mg/mL); and TM-10, the lowest in both (0.099 mg/mL of total phenolics). Antioxidant assays demonstrated dose-dependent scavenging activities: at 4 mg/mL, TM-8 exhibited the highest ABTS (> 50%) and hydroxyl radical scavenging rates, whereas TM-2 displayed the highest DPPH scavenging activity.
Conclusion:
The majority of G. elata samples comply with the most stringent international heavy metal standards, confirming their safety as food ingredients. The significant correlations between Titanium (Ti) and Magnesium (Mg) and total phenolics suggest their potential involvement in the accumulation of phenolic compounds, thereby possessing the potential to enhance the quality of G. elata. Our findings provide novel data support for cross-regional traceability and quality improvement of G. elata.