Compositional profiling and solvent-dependent self-assembly of native Vaccinium floribundum fractions into dual-phase lecithin liposomes with antibacterial and reducing activity

Vaccinium floribundum Kunth (mortiño), a wild Andean berry whose dual lipophilic–hydrophilic phytochemical composition has not yet been exploited for nanosystem design, was processed into native oily and aqueous fractions and evaluated for their ability to self-assemble into dual-phase lecithin liposomes. The fractions were recovered from macerated whole berries by Soxhlet extraction (6.09 ± 0.02% yield) and hydrodistillation (2.44 ± 0.08% yield), characterized by proximate analysis, atomic absorption spectroscopy and GC–MS, and nanoprecipitated using acetonitrile (ACN) or hexane (HEX) as the organic phase. GC–MS identified 21 compounds with reported antimicrobial or reducing activity. 3-O-caffeoylquinic acid preferentially partitioned into the aqueous fraction, where it accounted for 65.8% of the relative area, whereas naringenin was preferentially partitioned into the oily fraction, accounting for 31.2%, consistent with polarity-driven partitioning. ACN- and HEX-based liposomes measured 262 ± 5.7 nm and 166 ± 1.9 nm, respectively, and exhibited zeta potentials of −19.6 ± 1.9 mV and −19.0 ± 1.2 mV, respectively. Both formulations retained their vesicular morphology after lyophilization. In broth microdilution assays against Escherichia coli , ACN-based liposomes at 100% and 50% produced inhibition statistically comparable to gentamicin, with absorbance of 0.110 ± 0.002 compared with 0.732 ± 0.096 for the untreated control. However, all liposomal preparations produced smaller diffusion halos than the free fractions. The reducing capacity of the ACN-based liposomes exceeded that of the free oily fraction at every concentration tested, reaching 0.076 ± 0.002 compared with 0.045 ± 0.001 at 100%. Native mortiño fractions therefore self-assemble into food-grade dual-phase liposomes with solvent- and assay-dependent performance, providing a proof-of-concept for valorizing underutilized Andean berries as functional food ingredients.