Impact of ginger juice processing on volatile compounds and sensory characteristics of Eucommiae Cortex: A GC×GC-TOF-MS, E-nose, and machine learning analysis

Ginger-processed Eucommiae Cortex (G-EC) is a traditional herbal preparation with a long history of clinical application. However, the lack of quantitative standards, undefined chemical transformation pathways, and unidentified quality markers (Q-markers) have hindered its modernization. In this study, we developed an integrated analytical strategy combining comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF-MS), multivariate statistical analysis, and electronic nose (E-nose) technology to systematically investigate the volatile compound profile and sensory characteristics of Eucommiae Cortex (EC) before and after ginger processing. A total of 2806 volatile compounds were identified in G-EC, including 173 newly generated and 64 eliminated compared to EC. Sixty-five key flavor compounds were characterized, with enhanced woody, herbal, fresh, and minty notes in G-EC. E-nose analysis revealed distinct volatile signatures between EC and G-EC, with alkanes, alcohols, and sulfur-containing compounds as major differentiators. Furthermore, machine learning models combined with SHapley Additive exPlanations (SHAP) enabled accurate classification and interpretation of key chemical features. In conclusion, this study provides novel insights into the chemical transformation induced by ginger processing and offers a theoretical basis for the standardization and modernization of traditional Chinese medicine processing techniques.