Tomato fruit holds significant global economic value but is vulnerable to rapid ripening and pathogen infections, particularly by Botrytis cinerea, a major cause of postharvest losses (Rhouma et al., 2023). Although synthetic fungicides are commonly used to control B. cinerea, their prolonged use has led to the development of resistant strains, even when combined with other bioactive compounds (Mobasher Amini et al., 2023).

The rise of fungal resistance to conventional antifungals underscores the need for natural alternatives with minimal environmental impact. Essential oils (EOs) have shown promising antifungal properties (Dedong et al., 2025), and combining different EOs can enhance efficacy through synergy, reducing required doses (Purkait et al., 2020). Encapsulating EOs in matrices further improves their stability by enabling sustained release and reducing volatilization.

The effectiveness of edible coatings as postharvest treatments has been documented, as they help to preserve fruit quality and reduce contamination caused by phytopathogens. These coatings can be composed of proteins, carbohydrates, and lipids, or a combination of two or more of these (Zambrano et al., 2017).

One of the most used lipids is carnauba wax (CW), which is currently applied to tomatoes as a coating and shine enhancer (Devi et al., 2022). However, its use as a coating has limitations regarding its mechanical integrity, so it is necessary to combine it with another matrix to help mitigate this drawback and add other barrier characteristics. A possible alternative in postharvest is the use of Aloe vera (AV) gel as a polymeric matrix (Farooq et al., 2023), which is an excellent option for encapsulating compounds with antifungal activity, such as EO, due to its gelling capacity, which protects and releases the active ingredients in a controlled manner.

Essential oils are promising natural alternatives for fungal control due to their volatile compounds and chemical composition. Their use in edible coatings, active films, and nanoemulsions help preserve food without affecting sensory properties, although dosage must be regulated to avoid strong flavors (Ribes et al., 2017; Oliveira-Filho et al., 2022). Cassia essential oil (Cinnamomum cassia), rich in cinnamaldehyde, and Mexican lime essential oil (Citrus aurantifolia), high in limonene and other bioactives, have shown strong antifungal activity (Chahbi et al., 2020; Pahua-Angel et al., 2024). Studies confirm their effectiveness (Bosquez-Molina et al., 2010; Kočevski et al., 2013; Liu et al., 2022), with possible mechanisms including membrane disruption, metabolic inhibition, and interference with fungal signaling and biofilm formation. Despite the knowledge of the synergistic effects of EO, no reports have been found regarding their application in an emulsion based on CW and AV to inhibit plant pathologies.

The aim of this study was to evaluate the effect of a carnauba wax (CW) and aloe vera (AV)-based emulsion incorporating essential oils on the inhibition of Botrytis cinerea and the preservation of postharvest tomato quality. Additionally, the study examined whether these essential oils, individually or in fractional combinations, caused structural or functional alterations in the fungal cells that could explain their inhibitory effect.