Solid- and vapour-phase antifungal activities of six essential oils and their applications in postharvest fungal control of peach (Prunus persica L. Batsch)

Abstract

Plant-based essential oils (EOs) possess versatile antimicrobial effects, and these render EOs a potent, sustainable antimicrobial candidate for postharvest loss control. In this study, generally recognized as safe EOs of lavender, rosewood, dill weed and fennel were investigated with the benchmark thyme red EO, for their antifungal activity against six peach spoilage fungi. We further determined their chemical compositions, as well as monitored the effect of the EOs in the physical parameters of peaches during the storage period. Most EOs exhibited antifungal activity in the solid phase against the peach spoilage fungi, while some EOs failed to do so in the vapour phase. Rosewood (RO), thyme red (TR) and fennel (FO) EOs could inhibit mycelia growth and spore germination in a dose-dependent manner. GC-MS analysis indicated that the dominant compounds for TR, RO and FO were thymol (53.03%), linalool (77.09%) and trans-anethole (82.35%), respectively. The storage tests indicated that the peach treated with RO in the vapour phase exhibited a reduced decay and maintained weight loss and total soluble solids at the room and refrigerator temperatures. Moreover, the Mucor nidicola-infected peaches treated with RO exhibited significantly smaller lesion diameters and lower disease incidence relative to that by the control peaches.