Integrated multi-omics reveal the mechanisms of antioxidant, anti-inflammatory and aroma enhancement in Scytosiphon lomentarius via drying methods

Drying is fundamental to Scytosiphon lomentarius processing. This study systematically evaluated how vacuum freeze-dried, microwave-dried, and hot-air dried affect its bioactivity and quality. We found that freeze-dried sample demonstrated superior rehydration capacity, notably enhanced antioxidant activity, and elevated bioactive compounds such as total phenols and flavonoids. This anti-inflammatory advantage was further validated in an LPS-induced RAW 264.7 cell model. Untargeted UPLC-ESI-QTOF/MS E identified 135 non-volatile metabolites, with 18 differential metabolites as key to antioxidant activity variation. Molecular docking targeting iNOS revealed a marked increase in potential iNOS inhibitors in freeze-dried samples. Electronic nose analysis distinguished the three drying groups, while HS-GC–MS/MS tentatively identified 125 volatile compounds. Freeze-dried samples better retained Ionone, yielding caramel and creamy baked notes, while hot-air dried generated unpleasant dimethyl trisulfide. Collectively, freeze-dried proves optimal for S. lomentarius processing by best enhancing antioxidant capacity, anti-inflammatory activity, and characteristic volatile metabolites, providing a theoretical foundation for its high-quality production.