The Efficiency of Lemon Essential Oil-Based Nanoemulsions on the Inhibition of Phomopsis sp. and Reduction of Postharvest Decay of Kiwifruit

Abstract

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.