Nanoemulsion-Based Delivery of Essential Oils for Controlling Foodborne Pathogens and Spoilage Microorganisms

The increasing incidence of foodborne diseases and the limitations of conventional preservation methods have driven the search for safer, more effective, and sustainable antimicrobial strategies. In this context, essential oil nanoemulsions have emerged as promising alternatives to synthetic preservatives due to their broad-spectrum antimicrobial activity, natural origin, and potential applicability across diverse food matrices. This study critically examines the mechanisms of action of essential oils against pathogenic and spoilage microorganisms and discusses how their incorporation into nanoemulsions can overcome limitations such as low volatility, poor solubility, and chemical instability. The physicochemical principles governing the formation and stability of these nanoemulsions are addressed, alongside the influence of food matrix components (proteins, lipids, polysaccharides, pH, and ionic strength) on antimicrobial efficacy. Evidence from real food systems indicates that nanoemulsions often outperform free essential oils, although the magnitude of the effect strongly depends on matrix complexity and processing or storage conditions. The review further discusses critical aspects related to toxicity, safety, bioaccessibility, sensory acceptance, and regulatory considerations, as well as emerging evidence on adaptive responses and antimicrobial resistance risks associated with sublethal exposure to essential oil nanoemulsions. It is concluded that, despite their considerable technological potential, the industrial application of essential oil nanoemulsions requires further systematic studies in real foods, standardized protocols, and integrated risk assessments to ensure efficacy and safety under practical conditions.