Nanoencapsulation of Essential Oils for Food Preservation and Agricultural Applications: A Systematic Review of Biological Efficacy, Safety, and Technological Challenges

Essential oils (EOs) are promising natural bioactive compounds for food preservation and sustainable agriculture because of their antimicrobial, antifungal, antioxidant, and insecticidal properties. However, poor water solubility, high volatility, and chemical instability limit their practical application. Nanoencapsulation has emerged as an effective strategy to improve EOs stability, bioavailability, controlled release, and biological performance. This systematic review evaluated the efficacy, safety, and technological challenges of nanoencapsulated EOs for food and agricultural applications. The review followed PRISMA 2020 guidelines. Scopus, PubMed, and Web of Science were systematically searched, and original experimental studies reporting at least one safety-related outcome were included. Risk of bias was assessed using the Quality Assessment Tool for In Vitro Studies, and results were synthesized narratively. Of 776 records identified, 19 studies met the inclusion criteria. Nanoencapsulation generally improved EOs stability, controlled release, and biological persistence while frequently enhancing antimicrobial, antifungal, antioxidant, insecticidal, and preservation efficacy. Preliminary safety assessments, including cytotoxicity, hemolysis, phytotoxicity, sensory evaluation, and nanoparticle migration, were generally favourable. However, methodological heterogeneity, predominantly laboratory-based evidence, and limited long-term toxicity and industrial validation reduce the certainty of the evidence. Overall, nanoencapsulation represents a promising approach for enhancing the practical application of EOs, although standardized safety assessments and large-scale validation studies are needed before widespread commercial implementation.