Sustained photodynamic H2O2 generation via disodium 5′-inosinate enhances cooked meat preservation by membrane-targeted antibacterial action

Photodynamic inactivation (PDI) is a promising non-thermal antimicrobial technology known for broad-spectrum efficacy and low resistance potential. However, conventional PDI face limitations in bactericidal efficacy due to the short-lived and poorly diffusing reactive oxygen species (ROS). This study proposes a novel food-grade PDI strategy that incorporates disodium 5′-inosinate (IMP) into a vitamin B2 (VB2)-mediated system, significantly enhancing H 2 O 2 production. Acting as an electron donor, IMP promotes type I photochemical reactions, enabling sustained H 2 O 2 generation and achieving >6 log CFU/mL inactivation of Bacillus safensis , a spoilage bacterium often overlooked in cooked meat products. Mechanistic analyses showed that H 2 O 2 oxidized key phospholipids in the cell membrane, increased permeability, caused membrane potential hyperpolarization and ion leakage, and ultimately disrupted multiple membrane domains. Moreover, this strategy also exhibited persistent antimicrobial activity, effectively delaying spoilage in cooked meat products stored at 4 °C and 25 °C. Overall, this study introduces a safe and effective non-thermal sterilization method with promising industrial potential and offers a novel pathway to enhance PDI efficacy via intensified type I ROS mechanisms.