Control of Alternaria Rot of Cherry Tomatoes by Food-Grade Laurus Nobilis Essential Oil Microemulsion

Essential oils were widely reported to control the postharvest diseases of fruits. However, the stability and solubility limited the application of essential oils. The microemulsion loaded with Laurus nobilis oil was prepared with the optimal formula: oil/Tween 20/ethanol: 3/8/9, which was food-grade with the ability to be unlimitedly diluted with water and stable under high speed centrifugation and longtime storage. The in vitro test indicated that microemulsion showed great antifungal activity with the minimal inhibitory concentration and minimal fungicide concentration 500 g mL(-1) and 1000 g mL(-1). The in vivo test showed that 500 g mL(-1) microemulsion efficiently protected cherry tomatoes (Lycopersicon esculentum) from decaying. Microemulsion controlled the postharvest disease via damaging the cell membrane of pathogen and increasing resistance related enzymes activity. This work suggested that the oil/Tween 20/ethanol microemulsion could be used as a carrier to load L. nobilis oil, which had efficient antifungal activity in vitro and in vivo. Practical ApplicationsThe formula of the microemulsion developed in this study solved the problem of solubility and stability of Laurus nobilis essential oil, which enhanced the antifungal activity of essential oil. The microemulsion could be used as a fungicide to control the Alternaria rot of cherry tomatoes.