Comprehensive control of quality deterioration and shelf-life extension in sous-vide mussels using a nanoemulsion-liquid smoke hurdle approach.

The high perishability of farmed Mediterranean mussels (Mytilus galloprovincialis) limits their market distribution, necessitating mild hurdle technologies that preserve freshness without synthetic additives. This study addresses this industrial challenge by evaluating a novel synergistic hurdle technology approach combining sous-vide (SV) thermal processing (85 °C, 10 min), liquid smoke flavorings, and sunflower oil-based nanoemulsions during storage at 3 °C for 27 days. Physicochemical, microbiological, microstructural, molecular, textural, colorimetric, and sensory alterations were thoroughly characterized. Dynamic light scattering (DLS) showed that thermal processing actively altered the nanoemulsion interface, inducing a structural re-organization that significantly reduced droplet size from 253 nm to 190.15 nm, while high physical stability was maintained across groups with zeta potentials ranging from -24.45 ± 0.85 mV to 27.10 ± 3.10 mV. Combining nanoemulsion with liquid smoke (DNS group) established a powerful protective effect against protein and lipid degradation, effectively suppressing total volatile basic nitrogen (TVB-N) well below the regulatory limit of 35 mg N/100 g and minimizing free fatty acid accumulation. Structural integrity modifications characterized via SEM and FTIR revealed a more uniform and cohesive myofibrillar microstructure, likely stabilized by potential phenolic-protein interactions and reduced protein thermal degradation. Crucially, while the control (SV-only) and single nanoemulsion (ANS) groups exceeded microbiological limits by day 18, the combined DNS hurdle approach exerted a superior suppressive effect on microbial proliferation, extending the shelf life up to 24 days (compared to 21 days for liquid smoke alone and 18 days for control) while maintaining higher sensory acceptability. These findings demonstrate that this integrated strategy offers a promising, clean-label method to maximize quality retention in processed bivalves.