Essential oils (EOs) are natural antibiotic chemicals for food preservation; however, their use is challenging due to low solubility and high volatility. In this study, hybrid protein particles with hydrophobic interiors and colloidal stability were designed to carry hydrophobic eugenol with enhanced storage and thermal stability. Stable self-emulsified delivery systems (SEDSs) were facilitated by simply mixing eugenol with wheat proteins (WPs) and soy proteins (SPs) at pH 12 prior to neutralization. This strategy enabled protein co-folding that permitted the entrapment of eugenol with a high entrapment capacity of ca. 500 mg/g protein. Control over the SP/WP ratios contributed to tunable microstructural conformations, which in turn modulated the stability of SEDSs with prominent bacteriostatic properties against fungi when applied to rice cakes during long-term storage. These results underline the feasibility of properly utilizing EOs by binary protein structures, where the antibacterial properties of EOs could be manipulated coherently.
Keywords: antibacterial ability; eugenol; self-emulsifying; soy proteins; wheat proteins.