Preparation and characterization of carvacrol/ε-polylysine loaded antimicrobial nanobilayer emulsion and its application in mango preservation

Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address this limitation by combining carvacrol with whey protein isolate (WPI) to form nanoemulsion and enhancing antimicrobial properties and stability of nanoemulsion through ε-polylysine addition, thereby improving their application in fruit preservation. The results indicated that the nanoemulsion exhibited a double-layer structure. The physicochemical properties and storage stability were found to be favorable under the conditions of WPI (0.3 wt% v/v), Carvacrol (0.5 % v/v), and ε-polylysine (0.3 wt% v/v). In addition, the nanoemulsion had inhibitory effects on Staphylococcus aureus, Escherichia coli, and Aspergillus niger at concentrations of minimal inhibition concentration (32, 32, and 200 μg/mL, respectively). In addition, during a 7-day storage period, the nanoemulsion effectively preserved mangoes. Therefore, nanoemulsion could serve as a candidate for control of postharvest mangoes spoilage and extend its period of storage.