Synergistic changes and interrelationships among chemical composition, aroma, and color during the stir-frying of Sichuan pepper (Zanthoxylum bungeanum maxim.)

This study investigated changes in chemical composition, aroma, and color during Sichuan pepper stir-frying (0-10 min, 120 °C), identifying key contributors and a processing window. An integrated strategy combining colorimetry, electronic nose, HS-GC-MS, HPLC-UV, sensory, antioxidant, and molecular docking/dynamics analyses was applied. Color shifted from red to dark brown, with a* peaking at 5 min, while electronic-nose responses were highest at 4-6 min. Among 26 volatile compounds, (+)-limonene showed the highest ROAV (100), whereas eucalyptol declined sharply after 3 min. Molecular docking and dynamics supported stable binding of (+)-limonene to OR1A2. Total flavonoids and sanshools, as well as antioxidant activity, peaked at 5 min, while polyphenols continuously decreased. Multivariate analyses identified seven key contributors (VIP > 1), and correlation analysis showed associations of L* with bioactive constituents and a* with numbing-related constituents and antioxidant activity. 4-5 min was identified as a reference processing window for quality control.