Antibacterial activity of Camellia oleifera shells polyphenols against Listeria monocytogenes and its application for preserving sea bass during cold storage

Camelia oleifera Abel. ( C. oleifera ) is one of the four important woody oil-bearing crops worldwide. The fruit shells are the main by-product of C. oleifera processing, and contain a variety of polyphenols. This study attempted to evaluate the anti- Listeria monocytogenes (LM) abilities of C. oleifera shells polyphenols (CSP) in culture medium and sea bass matrix. Results showed that CSP exhibited strong anti-LM potential with a minimum inhibitory concentration of 400 μg/mL. The anti-LM activities of CSP was achieved by disrupting the integrity of cell membrane and wall, destroying the membrane protein conformation. Results from liposome model showed that CSP could interfere the lipid-water interface and hydrophobic core of cell membrane. Additionally, CSP had strong anti-biofilm activities against LM by inhibiting the bacterial aggregation and the production of biofilm protein and polysaccharide. Moreover, CSP was found to suppress the growth of microorganisms, prevent protein degradation and lipid oxidation, delay moisture migration, and keep sensory properties of sea bass fillets contaminated with LM during storage at 4 °C for 7 days. These findings suggested that CSP could be a natural and promising preservative for controlling LM in the fish products. • Camelia oleifera Abel. shells polyphenols (CSP) exhibited strong anti- L. monocytogenes potential with a MIC of 400 μg/mL. • CSP had strong anti-biofilm activities against L. monocytogenes . • CSP could keep the quality of sea bass fillets contaminated with L. monocytogenes during storage at 4 °C for 7 days.