Natural yam pigment as a dual‐type ROS photosensitizer: mechanism, biosafety, and application in fresh‐cut produce

BACKGROUND Photodynamic inactivation (PDI) is an emerging non‐thermal strategy for microbial control in food systems. However, few natural pigments are capable of generating both type I and type II reactive oxygen species (ROS), which limits their broad‐spectrum antimicrobial efficacy. RESULTS This study identified yam pigment (YP) as a dual‐type ROS photosensitizer that can produce both singlet oxygen and free radicals under 450‐nm blue light. YP‐mediated PDI significantly reduced the viability of Escherichia coli and Staphylococcus aureus through ROS‐induced lipid peroxidation and membrane disruption. In fresh‐cut cantaloupe, YP‐PDI delayed microbial spoilage at the same time as preserving sensory quality. Biosafety assays demonstrated minimal hemolytic activity and maintained Caco‐2 cell viability above 80% at antimicrobial doses. CONCLUSION YP serves as a safe, food‐grade photosensitizer with dual ROS‐generating capacity, offering effective microbial inactivation without chemical residues or thermal damage.