From complexity to simplicity: a traditional-inspired roasting-sealing process enhances jujube aroma and antioxidant...

Smoked jujube ("Wu Zao"), a time-honored Chinese delicacy crafted through generations of drying and smoking, is a laborious process. This study simplified the process into a two-step method: dry-heat roasting (190 °C, 2 min) followed by sealed aging (14 d). Four groups were compared: control (CK), sealed-only (CK-S), roasted-only (CK-R) and combined treatment (JX). Compared with others, JX showed superior flavor attributes, with higher antioxidant compound accumulation (e.g., phenolics: 13.2 vs 9.2 mg/g DW). Strong Maillard reaction was evident from 5-hydroxymethylfurfural (∼17-fold increase). Metabolomics identified 854 differential metabolites, including upregulated flavor-active compounds (e.g., 6-gingerol) and antioxidants (e.g., ferulic acid). Compared with traditional Wu Zao, JX showed a closely comparable overall sensory profile, but with stronger aroma and higher antioxidant capacity, despite lower sweetness and softness. This work demonstrates that roasting-sealed aging synergy induces chemical transformation beyond preservation, offering a practical strategy for nutritious, flavor-rich fruit products.