Food‐Grade Microbial‐Origin Antimicrobial Peptides: Structure–Activity Relationships, Mechanisms of Action, and Applications in Food Preservation

The pervasive threat of microbial contamination and the escalating crisis of antimicrobial resistance necessitate the development of novel, sustainable food preservation strategies. Antimicrobial peptides (AMPs), especially those sourced from food-grade microbes, are emerging as feasible substitutes for conventional chemical preservatives. They provide substantial benefits, including biodegradability, excellent biocompatibility, and a beneficial foundation for later safety evaluations and risk management. This review critically synthesizes current knowledge on AMPs sourced from edible fungi, fermented fungi, and probiotics. It systematically reviews AMP biosynthetic pathways and sources, with an emphasis on structure-activity relationships to link structural features to antimicrobial activity and safety. It further analyzes mechanisms of action across two major modes, membrane targeting and intracellular targeting, and surveys AI-assisted de novo design strategies. Advanced preparation and screening workflows are summarized. Finally, it discusses progress and limitations in food systems and emerging applications in active and intelligent packaging. Key insights reveal that food-grade microbial AMPs are predominantly cationic and amphipathic, with their activity fine-tuned by molecular weight, amino acid composition, and secondary structure. Incorporating these peptides into nanofiber membranes, nanoparticle delivery systems, and biosensors can mitigate the constraints associated with their direct application as antimicrobial agents in food. This method efficiently prolongs food shelf life and facilitates real-time quality assessment. However, challenges such as batch-to-batch variability leading to inconsistent activity, cost-effective production, and the need for standardized safety assessment remain. Thus, future research should focus on the synergistic role of multiomics, AI-assisted design, and precision fermentation in propelling the field toward sustainable and intelligent food packaging solutions.