Milk phospholipids-based nanostructures functionalized with rhamnolipids and bacteriocin: Intrinsic and synergistic antimicrobial activity for cheese preservation

Milk fat globule membrane (MFGM) phospholipids-based nanostructures were developed and their functionalization with rhamnolipids (RLs) was carried out to enhance the preservation of cheese against resistant food borne pathogens i.e., Listeria monocytogenes and Escherichia coli. Void (without nisin) and nisin-loaded RLs functionalized MFGM nanostructures (RLs-MFGM-NS) were fabricated by ultrasonication-assisted self-assembly method. Cubic morphology of void and loaded RLs-MFGM-NS and pristine MFGM nanostructures (MFGM-NS) was observed under scanning electron microscopy (SEM), which indicated uniform size ranging from 43 nm (void RLs-MFGM-NS) to 194 nm (loaded RLs-MFGM-NS). FTIR analyses confirmed the electrostatic interaction, predominantly H-bonding and linkage of carboxyl ester group of MFGM with C-H group in RLs after functionalization of NS. Furthermore, quantitative antimicrobial assay on cheese slices confirmed the broad-spectrum potential of intrinsically active nanostructures (due to RLs) having synergistic activity with nisin against L. monocytogenes and E. coli. Hence, nisin-loaded RLs-MFGM-NS can be applied as promising bioactive additives for sustained preservation of cheese.