Potato Protein-based Nanoemulsion of Oregano (Origanum vulgare) Essential Oil: A Promising Strategy Against Escherichia coli O157:H7

This study successfully developed nanoemulsions (NEs) with distinct physicochemical properties using the same protein to encapsulate essential oils (EOs). Formulations containing 1% patatin-rich fraction (PP-200), oregano EO, and medium chain triglyceride (40:60) exhibited nanometric sizes (< 300 nm) and well-defined zeta potentials ranging from 40.48 to 38.73 at pH 3 (NE3) and from -28.71 to -34.45 at pH 7 (NE7). NE3, however, did not maintain its nanometric size upon exposure to pH 7. When salt was introduced, aggregation occurred at 300 mM for NE7 and 400 mM for NE3. Both NEs showed thermal stability, but NE3 exhibited superior stability during storage, remaining intact for 12 days at 4°C and 25°C. Moreover, NE3 demonstrated enhanced anti-Escherichia coli O157:H7 activity, achieving a 7 log CFU/mL reduction at concentrations two times lower than NE7. These findings suggest that the developed NEs have potential for application in various food matrices, promoting the broader use of EOs in the food industry.