Development of a sonodynamic approach for Listeria monocytogenes inactivation and quality preservation in strawberries.

This study developed an ultrasonically activated sonosensitizer composite, curcumin-lecithin-propyl gallate-zein (CLPGZ) nanoparticles, evaluated its bactericidal mechanism of Listeria monocytogenes and its potential in food preservation applications. The synthesized CLPGZ nanoparticles were characterized for their physicochemical properties, including particle-size distribution, storage stability, and antioxidant activity. In conjunction with low-frequency ultrasound treatment, CLPGZ effectively induced the generation of reactive oxygen species (ROS) via sonodynamic effects, leading to bacterial protein leakage, nucleic acid damage, and membrane lipid peroxidation, as evidenced by increased malondialdehyde (MDA) levels. These effects jointly disrupted bacterial structural integrity, enhancing antimicrobial efficacies. In a strawberry washing simulation experiment, the combination treatment of CLPGZ and ultrasound reduced L. monocytogenes counts on strawberries to below 2 log CFU/g. Additionally, storage trials showed its beneficial effects in preserving strawberry firmness and stabilizing soluble solid content (SSC). Taken together, this study provided both theoretical and practical insights for the development of an innovative non-thermal sterilization and preservation technologies for fresh produce.