Sustainable Cheese Preservation: Harnessing the Power of Thyme and Carvacrol Against Fungi

This study investigated a sustainable and natural strategy to control fungal growth on the surface of Italian Caciocavallo cheese using essential oils. Fungal contamination is particularly critical due to the potential production of mycotoxins. Five essential oils—Salvia officinalis, Laurus nobilis, Thymus vulgaris, Origanum vulgare, and Carvacrol— were initially evaluated in vitro against the mycelial growth and spore germination of common spoilage fungi, including Fusarium avenaceum, Penicillium fuscoglaucum, Paecilomyces variotii, Penicillium commune, Aspergillus montevidensis, Aspergillus flavus, and Alternaria alternata, isolated from Caciocavallo cheese. Among the tested essential oils, Thymus and Carvacrol demonstrated strongest antifungal activity and were further used in a Central Composite Design (CCD) to optimize their concentrations in a mix emulsion. Ten emulsified EO formulations were prepared and applied by spraying onto the surface of Caciocavallo cheese and stored at 10 °C for 30 days. At the end of the storage, fungal growth was monitored, and key physicochemical parameters were evaluated, including water activity (aw), pH, moisture content, texture, and color. Emulsion formulation of 1.25% Thymus 1.25% Carvacrol, exhibited significant antifungal efficacy without inducing substantial changes in the physicochemical or sensory attributes of the cheese. These findings support the application of essential oils as natural and environmentally friendly bio preservatives, offering a promising approach to enhance the microbial safety and shelf life of traditional cheeses such as Caciocavallo.