Discrimination of the commercial spice "Green Pepper" (Zanthoxylum) using integrated morphological, genetic, and volatilomic approaches.

The integrity of the global spice trade is contingent upon accurate species authentication. "Green Pepper", a high-value spice derived from Zanthoxylum plants, faces severe misidentification in China due to shared vernacular names, primarily between Zanthoxylum armatum and Zanthoxylum schinifolium. This confusion jeopardizes product quality, consumer trust, and the reliability of scientific research. To address this, we employed an integrated strategy that combined field surveys (34 plantations), an audit of cultivated varieties (20 geographical indication and 17 common cultivars), a nomenclatural audit (38 taxon-market name pairs), molecular authentication (using seven fluorescent SSR markers), and chemical analysis (GC-MS profiling of 126 volatile compounds). Our results demonstrated a significant genetic distinction and a clear divergence in volatile profiles between the two species. Multivariate statistical analyses identified species-specific markers, with Z. armatum characterized by high emissions of limonene, linalool, and β-pinene, and Z. schinifolium defined by the exclusive and dominant emission of estragole. Bibliometric analysis quantified a strikingly high mislabeling rate (89.80% in Chinese literature; 72.90% internationally), largely attributable to ambiguities in geographical records. This study conclusively identifies Z. armatum as the dominant commercial source of "Green Pepper" in China. More importantly, it provides a set of reliable chemical and molecular markers for its authentication. The multimodal methodology established here offers a powerful, transferable framework for ensuring quality control and traceability in the spice industry, safeguarding both economic value and consumer interests.