Disrupting Aeromonas sobria quorum sensing with HNTs-zingerone embedded CS/CMC-Na film: A novel strategy for prolonging freshness of refrigerated sea bass fillets

Abstract

Aeromonas sobria, recognized as a psychrotrophic specific spoilage organism in refrigerated aquatic products, facilitates its proliferation by metabolizing proteins, lipids, and carbohydrates, thereby generating spoilage-associated metabolites and compromising product quality. Quorum sensing (QS), a bacterial cell-to-cell communication mechanism, orchestrates the secretion of virulence and spoilage factors in A. sobria via the LuxI/R QS system. Targeting this regulatory pathway presents a novel strategy to mitigate spoilage and extend the shelf life of aquatic products. Previous studies have demonstrated that zingerone (ZRN) exhibits quorum-quenching activity at sub-inhibitory concentrations; however, its practical application is constrained by limited solubility and bioavailability. To overcome these challenges, ZRN was encapsulated within halloysite nanotubes (HNTs) and incorporated into a self-assembled composite film composed of chitosan (CS) and sodium carboxymethyl cellulose (CMC-Na). The fabricated film was characterized for its structural, thermal, and mechanical properties and subsequently evaluated for its preservation efficacy on refrigerated perch fillets. The composite film exhibited a homogeneous surface morphology with uniformly dispersed HNTs, alongside adequate thermal stability, tensile strength, and physicochemical attributes suitable for refrigerated aquatic product preservation. Notably, the film suppressed spoilage indicators, including total volatile basic nitrogen (TVB-N) accumulation, lipid peroxidation, and bacterial spoilage potential, without inhibiting A. sobria growth. Furthermore, it mitigated muscle tissue degradation and biogenic amine formation in perch fillets during refrigerated storage. Molecular docking simulations revealed that ZRN competitively binds to the LuxR-type receptor at the same binding pocket as the endogenous autoinducer C₄-HSL, thereby disrupting QS signaling. Collectively, this ZRN-loaded composite film represents a promising biodegradable packaging solution for enhancing the quality and shelf life of refrigerated aquatic foods.