Beyond Bactericidal: Plasma Surface Engineering to Defeat Food Matrix-Conditioning Layers

The persistence of foodborne pathogens on industrial food contact surfaces continues to challenge global food safety despite advances in sanitation technologies. A central limitation of current antimicrobial strategies lies in their validation under simplified laboratory conditions that overlook the physicochemically driven formation of food matrix conditioning films. Upon contact with food residues, organic macromolecules reorganize at the solid‒liquid interface, forming conditioning layers that mask engineered surface functionalities and facilitate microbial attachment. This review examines how such interfacial transformations constrain conventional bactericidal approaches and contribute to sanitization failures in industrial environments. Plasma surface engineering is evaluated as a matrix-aware strategy capable of tailoring surface energy, hydration behavior, and nanoscale architecture through plasma-enhanced chemical vapor deposition and magnetron sputtering. These approaches may mitigate organic fouling and modulate bacterial surface sensing under controlled conditions. Particular attention is given to mechanotransduction pathways implicated in early biofilm formation, highlighting how nanoscale surface cues influence c-di-GMP signaling and biofilm commitment in both Gram-negative and Gram-positive foodborne pathogens, including Salmonella spp. and Listeria monocytogenes. Significant translational gaps remain, including long-term durability under repeated cleaning-in-place cycles, antimicrobial transport through complex conditioning films, and adaptive tolerance under chronic exposure. This review situates plasma surface engineering within a preventive interfacial design framework, offering an evidence-based rationale for the development of food contact materials capable of meeting the durability, safety, and regulatory demands of modern processing environments.