Stability, release behavior and bacteriostatic property of potato protein isolate-soy lecithin-based Pickering...

The poor stability and strong volatility of cinnamon essential oil (CEO) limit its application in the food preservation. Potato protein isolate (PP), soy lecithin (SL) and CEO were used to prepare Pickering emulsions (PEs) to achieve the assembly of stable antimicrobial PEs, and its in vitro release kinetics was investigated in this study. Intrinsic fluorescence spectra and Fourier transform infrared spectra confirmed that the binding of SL with PP to form the PP-SL complexes (PPSLs) through hydrophobic interactions, electrostatic attraction and hydrogen bonds. At the mass ratio of PP to SL of 3:1, PPSLs exhibited the best emulsifying properties (51.67 m²/g, 92.06 %) and surface hydrophobicity (124.80). The PEs stabilized by 2.0 % PPSLs had the smallest particle size (24.39 μm) and the highest environmental stability, and were stable at 4 °C for 21 days. The encapsulation efficiency of CEO was increased from 44.36 % to 90.61 % as the PPSLs concentration rose from 0.1 % to 2.0 % (wt/wt). The release curves and kinetic fitting experiments demonstrated that the release behavior of the CEO in PEs was most consistent with the First-order kinetic equation. This proved that the coating of the PEs was beneficial to postponing the release of CEO. In vitro antimicrobial tests found that CEO did not inhibit the reproduction of E. coli BL21 after heating for 30 min, while the CEO-PEs remained a high bacteriostatic activity under the same conditions. This study has demonstrated the CEO loaded PPSLs-based emulsion may be used as a novel antibacterial emulsion.