The Role of Nanoemulsions of some Essential Oils in Improving the Quality of White Soft Cheese

White soft cheese is highly risky for contamination during processing, handling and storage by a variety of spoilage and/or pathogenic microorganisms. Therefore, the nanoemulsions (NEs) of Thyme and Clove essential oil (EO) were prepared by ultrasonication (as delivery systems) to be used as a natural preservative for ultrafiltrated (UF)-soft cheese. The prepared NEs were characterized by Dynamic light scattering (DLS) for particle size. Different concentrations of Thyme NE (0.03, 0.06 and 0.1%) as well as Clove NE (0.06, 0.1 and 0.25%) were used to preserve UF-cheese. The research aimed to study the characterization of NEs of Thyme and Clove EOs, as well as their effects on the sensory and microbiological properties of UF-cheese along the storage period of 50 days at 7 °C.The results revealed that the droplet size of the prepared NEs was 94.85 and 68.67 nm for Thyme and Clove NE, respectively. The sensory evaluation demonstrated that UF-soft cheese fortified with NEs remained acceptable. The highest sensory acceptance was related to the cheeses fortified with 0.03 and 0.06 % Thyme and Clove NE, respectively. The results of microbial groups indicated that NEs of both EOs added to retentate resulted in a decrease in the total bacterial count (TBC), compared with the control one. The concentrations of 0.1% and 0.25% of Thyme and Clove NE, respectively, inhibited the growth of psychrotrophic bacteria, as well as yeasts and mould until the end of the storage period. These findings recommend using NEs of Thyme and Clove EOs, as a natural preservative, to maintain the soft white cheese's quality and prolong its shelf life.