Essential oils (EOs) have excellent antibacterial activity and are generally recognized as safe (GRAS) for use in food preservatives. However, the application of EOs is limited because of their strong volatility and easily oxidized. Encapsulation of EOs into nanoemulsions could effectively prevent oxidative deterioration. In this study, lemon essential oil-based nanoemulsion (LEO/NE) was prepared by high-pressure homogenization. FT-IR and encapsulation efficiency analysis indicated that LEO was effectively encapsulated in the nanoemulsion. The results of zeta potential changes after 35 d storage indicated that LEO/NE exhibits good stability at room temperature. The effect of LEO/NE on the main soft rot pathogens of kiwifruit Phomopsis sp. was investigated, and the results showed that LEO/NE significantly inhibited spore germination and mycelia growth of Phomopsis sp. by promoting ROS accumulation, intracellular antioxidant enzyme activities, and cell apoptosis. The preservation experiment was carried out by inoculating Phomopsis sp. spores into fresh kiwifruit, and the LEO/NE effectively inhibited soft rot development in kiwifruit in a LEO dose dependent manner. LEO/NE with 1% LEO loading amount has a good effect on preventing postharvest decay of kiwifruit caused by Phomopsis sp.

In this work, a lemon essential oil–rutin composite nanoemulsion was formed and integrated into a chitosan (CS) matrix to form a coating for pork preservation. The introduction of rutin decreased the particle size of the nanoemulsion and suppressed the volatilization of the encapsulated essential oil. The rheological properties of the coating showed that it was a pseudoplastic fluid with shear-thinning behavior, and the apparent viscosity of the system was lower than 0.7 Pa·s. The incorporation of the nanoemulsion significantly (p < 0.05) increased the antioxidant and bacteriostatic properties of the CS coating, which was positively correlated with the content of the incorporated nanoemulsion. Pork preservation experiments revealed that the changes in color, the increase in pH, drip loss, thiobarbituric acid-reactive substances, total volatile basic nitrogen and total viable count were significantly (p < 0.05) delayed by the coating treatment. These results suggest that the formed lemon essential oil/rutin/CS coating has promising applications in pork preservation.

In this study, we investigated the preservation efficacy of a lemon essential oil-rutin-chitosan (CS-LEO/NE-R) composite coating on seasoned white snakehead fillets and systematically evaluated dynamic metabolite changes via untargeted metabolomics. The results demonstrated that the composite coating significantly (p < 0.05) suppressed microbial proliferation while delaying increases in pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS), thereby extending the microbial spoilage threshold by 5 days. Untargeted metabolomics identified 2271 metabolites, with differentially abundant metabolites predominantly involving amino acids and their derivatives, organic acids and their derivatives, and glycerophospholipids. KEGG enrichment analysis suggested that the composite coating maintained cellular membrane stability and was associated with alterations in glycerophospholipid, arachidonic acid, and linoleic acid metabolism pathways linked to membrane integrity, enhanced antioxidant defences, and regulation of energy metabolism homeostasis. Concurrent enrichment of α-linolenic acid metabolism further pointed to altered fatty acid metabolism, consistent with reduced lipid peroxidation product accumulation.