Natural Pigment-mediated Photodynamic Antimicrobial Technology: Mechanisms and Food Applications

Abstract:

Photodynamic antimicrobial technology (PDT), as a non-thermal physical bactericidal method, has received increasing attention due to its high efficiency, low residue, and lack of resistance induction. Natural pigments, as food-grade photosensitizers exhibit excellent optical responsiveness and biocompatibility. Studies have shown that curcumin, chlorophylls, and porphyrin-based pigments exhibit favorable photodynamic antimicrobial efficacy in various food matrices including fruits, vegetables, meat, and drinking water. The author summarizes the photodynamic antimicrobial mechanisms of representative natural pigments, and analyzes the effects of light parameters, photosensitizer concentrations, and food matrices on photodynamic antimicrobial efficacy. Furthermore, the recent progress of PDT applications in fruit and vegetable surface disinfection, drinking water sterilization, and smart packaging is reviewed, with a focus on the role of nanocarriers and composite films in enhancing photodynamic antimicrobial performance. Finally, the industrial application potential of natural pigment-mediated PDT in food processing is discussed, along with the challenges regarding photosensitizer stability and process standardization. Future research directions are proposed, emphasizing synergistic antimicrobial mechanisms and the development of functional materials for practical implementation.