Sunflower wax-structured oil phase confers robustness to W/O/W emulsion gel beads for enhanced probiotic viability

This study explored impact of natural waxes (beeswax, BW; rice bran wax, RBW; sunflower wax, SFW)-mediated oil-phase gelling on the physicochemical properties and probiotic-protective efficacy of W/O/W emulsion gel beads co-encapsulating Lactobacillus plantarum and Streptococcus thermophilus. Wax incorporation preserved "two-membrane, three-phase" emulsion architecture while increasing droplet sizes and viscosity, with SFW and RBW yielding denser, more uniform bead microstructures and reduced moisture mobility compared to controls (without wax, NW) and BW. XRD and DSC revealed β'-polymorphic crystals in RBW and SFW, correlating with higher melting points and thermal stability. During pasteurization, simulated gastrointestinal digestion, and 28-day storage in acidic orange juice, SFW beads exhibited superior probiotic viability, with log CFU reductions minimized to 2.6 for Lactobacillus plantarum and 2.0 for Streptococcus thermophilus, versus 3.4 and 3.1 in NW. This approach holds significant promise for improving probiotic encapsulation in functional foods, enabling targeted delivery and extended shelf-life under adverse conditions.