From In Vitro Antimicrobial Activity to Food Applications: Limitations of Essential Oils in Real Food Systems

Essential oils have attracted considerable attention as natural antimicrobial agents for food preservation due to their broad-spectrum activity against foodborne microorganisms. Although numerous studies report strong antimicrobial effects under in vitro conditions, their effectiveness in real food systems is often substantially reduced. This review critically examines the discrepancy between in vitro antimicrobial activity and actual performance in food matrices. Particular attention is given to the influence of food matrix interactions, physicochemical instability, volatility, sensory limitations, and microbial adaptation on the efficacy of essential oils. A conceptual framework is presented to systematically summarize the major factors limiting antimicrobial performance in practical food applications. In addition, current strategies aimed at improving applicability, including encapsulation technologies, nanoemulsions, synergistic combinations, and active packaging systems, are discussed. Available evidence indicates that simplified experimental models frequently overestimate the practical efficacy of essential oils. More realistic and system-oriented evaluation approaches are therefore necessary to improve the translation of laboratory findings into food applications. Overall, essential oils remain promising candidates for natural food preservation, although their successful industrial application will depend on overcoming important technological and practical limitations.