Antifungal properties of hybrid films containing the essential oil of Schinus molle: Protective effect against postharvest rot of tomato

The control of postharvest diseases in tomatoes using hybrid films represents an efficient and inexpensive alternative to avoid economic losses. This work reports on the design, characterization, and in situ application of hybrid films containing chitosan combined with the leaf essential oil of Schinus molle (SmEO) as antifungal agents. These materials were tested in situ on Lycopersicon esculentum cv. uva showing symptoms of soft rot caused by Fusarium oxysporum. According to our analytical conditions, SmEO contained β-phellandrene (15.7%), α-phellandrene (12.1%), elemol (9.1%), apiole (6.4%) and camphene (6.2%) as the most abundant volatiles. Four distinct hybrid films were prepared from 1% chitosan combined with different amounts of SmEO (0.05, 0.1, 0.3 and 0.7% w/v) to generate four hybrid films named FSm1, FSm2, FSm3 and FSm4. The spectroscopic properties (FT-IR), texture and thickness (SEM), and optical properties (transmittance) of these films revealed that FSm3 and FSm4 had the best physicochemical and in situ antifungal properties to avoid conidial germination and mycelial proliferation of F. oxysporum. The fruits treated with films and essential oil showed a statistically significant delay (>50%) in mycelial growth compared with the control groups (p < 0.05) and a substantial decrease in conidial viability over 6 days (<2%). According to our results, FSm3 and FSm4 significantly avoided the in situ growth of F. oxysporum in tomatoes. Interestingly, all of the films significantly improved fruit firmness in comparison with untreated tomatoes (p < 0.05). The properties of the films reported in this work may improve the shelf life of Lycopersicon esculentum cv. uva.