Effect of Eugenol Nanoemulsion on Microbial Load and Sensory Properties of Fresh-Cut Papaya During Storage

Fresh-cut fruits are increasingly valued for their convenience and nutritional benefits; however, their shelf life is limited by physicochemical and microbiological changes that occur after peeling and cutting. Among emerging preservation strategies, essential oils stand out for their antimicrobial properties, although their direct use is hindered by high volatility, low water solubility, and a strong sensory impact. Nanoemulsions offer a promising alternative to overcome these limitations. In this study, eugenol nanoemulsions were formulated using sonication and evaluated for their effect on the microbial load and sensory attributes of fresh-cut papaya stored at 4°C. The resulting nanoemulsions had a particle size range of 9.78 to 210 nm and zeta potential values ranging from -5.29 to -7.44 mV. Physical stability, assessed by creaming index, varied from 0% (0.4% eugenol) to 100% (0.6% eugenol) at the end of the storage period. In vitro assays demonstrated that eugenol nanoemulsions reduced the growth of Listeria monocytogenes and Salmonella Typhimurium by 1.2 to 5.4 Log CFU/mL. When applied to inoculated papaya, significant microbial reductions (1.5 to 5 Log CFU/mL) were maintained over 15 days for both pathogens. The nanoemulsions altered the aroma and taste of the papaya, while color and texture remained unaffected.