Stevia vs. sucrose in saffron-loaded water-in-oil-in-water double emulsions: stabilization mechanisms, rheological...

This study evaluated stevia as a sucrose substitute in saffron-loaded water-in-oil-in-water (W₁/O/W₂) double emulsions during 28-day storage. Time-intensity analysis confirmed 0.06% stevia matched 4% sucrose sweetness (I_max ≈ 6.0). Stevia formulations exhibited superior stability with 0% creaming, smaller droplet sizes (11.9-13.3 μm), narrow size distributions (span 1.53-1.76), and maintained viscoelasticity (G': 3.8-4.4 Pa) compared to sucrose systems. Increasing saffron to 7.5% enhanced stability through biopolymer interactions. FT-IR spectroscopy confirmed saffron encapsulation via hydrogen bonding (O-H/N-H at 3383 cm^-1), PGPR interfacial stabilization (CO at 1746 cm^-1), and polysaccharide interactions (CO at 1022-1076 cm^-1). Absence of crocin's CC band (1649 cm^-1) verified inner-phase compartmentalization. Results demonstrate stevia and elevated saffron concentrations synergistically improve emulsion stability, offering a clean-label approach for sugar-reduced functional beverages with enhanced bioactive retention.