Seafood spoilage induced by microbial contamination has caused substantial economic losses and resource waste to the global food industry in recent years, posing a long-term challenge to the sustainable development of the supply chain (Liu et al., 2025). Large yellow croaker (Larimichthys crocea), one of the most important marine species in East Asia, is highly favored by consumers due to its abundance of high-quality proteins and ω-3 fatty acids (Lu et al., 2024). However, the species is highly perishable because of its soft tissue and high moisture content, making it highly susceptible to microbial contamination during harvesting, transportation, and storage, which leads to rapid quality deterioration (Chong et al., 2024).

Specific spoilage organisms (SSOs), including Shewanella, Pseudomonas, and Aeromonas, have been identified as the dominant contributors to the deterioration of Larimichthys crocea (L. crocea)(Chen et al., 2025). In particular, Shewanella putrefaciens secretes proteases that degrade myofibrillar proteins (Yi et al., 2023) and accelerates the accumulation of off-flavor compounds via the ATP degradation pathway (Chen et al., 2024). Meanwhile, Pseudomonas species metabolize amino acids to produce biogenic amines such as putrescine, thereby further compromising food safety (Yan et al., 2023). Currently, low-temperature storage and chemical preservatives are widely applied to retard spoilage. However, refrigeration merely inhibits microbial proliferation without eliminating spoilage organisms, while chemical additives raise safety concerns and face limited consumer acceptance. Therefore, the development of novel non-thermal inactivation strategies that are efficient, safe, and capable of targeted microbial inhibition is of great significance for maintaining the storage quality of highly perishable aquatic products such as L. crocea.

Photodynamic inactivation has emerged as a promising non-thermal inactivation technique in recent years. This approach relies on the synergistic action of a photosensitizer, a specific light source, and oxygen to generate large amounts of reactive oxygen species (ROS), which efficiently inactivate microorganisms while minimizing the risk of resistance development (Dias et al., 2020). Notably, ROS generation in SPDT is strictly driven by external energy inputs from light and ultrasound. Once the excitation sources are turned off, the sono/photodynamic sensitizers immediately revert to their ground state, and ROS production ceases instantly, avoiding the sustained chain reactions typically associated with chemical oxidants (Pang et al., 2020). In addition, sensitizers such as curcumin possess inherent antioxidant properties, enabling them to rapidly quench residual trace ROS within a short period after ultrasound and light irradiation end, thereby further preventing propagation of radical chain reactions (Dai et al., 2022). In summary, ROS generated during SPDT do not undergo uncontrolled extension; their instantaneous decay, energy dependence, and the intrinsic antioxidant capacity of the system collectively ensure that this technology does not induce persistent oxidative damage when applied to food matrices.

Although extensive research has demonstrated the remarkable advantages of photodynamic technology in microbial inactivation and food preservation, some studies have also reported potential drawbacks under specific conditions, indicating the need for caution in methodological design and practical applications. At present, most highly efficient synthetic photosensitizers have not yet been approved under existing food safety regulations (Sardana et al., 2026), and their degradation pathways, toxicological profiles, and long-term exposure risks remain insufficiently evaluated. In addition, many food-grade photosensitizers (e.g., curcumin) exhibit poor solubility and dispersibility in aqueous systems (Dai et al., 2025), which may inadvertently cause coloration issues in food products. Furthermore, although photodynamic technology performs well in transparent and high-viscosity matrices, its antimicrobial efficiency decreases markedly as sample transparency declines (Lin et al., 2024), compromising microbiological stability. Naturally occurring antioxidants in food—such as β-carotene, cysteine, histidine, and ascorbic acid—may also quench the singlet oxygen generated during photodynamic treatment, thereby reducing its oxidative efficacy (Chai et al., 2021). Additionally, the limited penetration depth of visible light restricts its ability to inactivate microorganisms residing in deeper layers of food matrices (Yan et al., 2024). It is also worth noting that current synergistic inactivation strategies based on photodynamic principles still lack well-established theoretical frameworks, and their molecular mechanisms remain incompletely understood (Zhou et al., 2025). Moreover, the impacts of photodynamic processing on food quality and flavor characteristics have not yet been systematically characterized.

In recent years, ultrasound has been introduced to act synergistically with specific light wavelengths in activating photosensitizers, giving rise to sono/photodynamic technology (SPDT)(Cheng et al., 2025). SPDT enhances ROS generation by combining cavitation effects and sonoluminescence during ultrasound exposure (Yan et al., 2024). Moreover, ultrasound exhibits a greater penetration depth than light, and the microstreaming and microjets generated by cavitation can facilitate the migration of sonosensitizers into deeper tissues and promote their intracellular accumulation (Pang et al., 2020). These advantages make SPDT particularly suitable for complex food matrices and provide the potential to overcome the surface-limited inactivation barrier of conventional photodynamic inactivation. Previous studies have demonstrated that curcumin-mediated SPDT effectively inactivated Escherichia coli and Staphylococcus aureus in orange juice while preserving most nutritional components (Bhavya & Hebbar, 2019), and suppressed spoilage microorganisms in shrimp surimi during refrigerated storage, thereby extending its shelf life (Wang et al., 2021). However, the effects of different ultrasonic frequency modes on SPDT efficacy remain largely unexplored, and evidence regarding its application in fresh aquatic products is still insufficient.

Curcumin, the most representative food-grade sono/photosensitizer, is a natural polyphenolic compound derived from the rhizomes of Curcuma longa (Dai et al., 2025). It has been widely used not only as a natural colorant and functional ingredient (food additive code E100), but also as a subject of extensive research due to its photophysical properties and antioxidant activity (Lin et al., 2021). Structurally, curcumin contains a conjugated diketone backbone and multiple phenolic hydroxyl groups, which confer strong photophysical and antioxidative characteristics. Upon exposure to blue light, curcumin can be activated to generate ROS, effectively inactivating microorganisms without leaving toxic residues (Dias et al., 2020). Furthermore, curcumin has been reported to possess additional health-promoting effects, including anti-inflammatory, antibacterial, and anticancer activities (Q.-Q. Yang et al., 2020). More recently, curcumin has gained attention as a promising sono/photosensitizer because ultrasound can enhance its dispersion, cellular uptake, and ROS generation through cavitation (Xu et al., 2018; Zhang et al., 2022). These unique advantages make curcumin an ideal candidate for developing non-thermal SPDT-based preservation strategies in food systems, ensuring microbial safety while maintaining nutritional and sensory quality.

Therefore, in this study, a laboratory-constructed sono/photodynamic system (Fig. S1) was employed to systematically evaluate the antimicrobial and preservation efficacy of curcumin-mediated SPDT treatment under different ultrasonic frequency modes, using S. putrefaciens and refrigerated L. crocea as model systems. By integrating physicochemical parameters, sensory attributes, and odor fingerprinting analyses, the microbial targets of SPDT were elucidated. This study not only provides mechanistic insights into the microbial inactivation pathways of SPDT but also offers theoretical support and technical evidence for its application in cold-chain preservation of high-value aquatic products.