Thermal Protection of Probiotics Using Phase‐Change Material Stabilized Water‐In‐Water Pickering Emulsions

ABSTRACT Spray drying is critical for probiotic stabilization but exposes sensitive bacteria to damaging high instantaneous temperatures. To mitigate this thermal stress, this study developed a novel water‐in‐water (W/W) Pickering emulsion system stabilized by using solid lipid nanoparticles (SLNs) composed of beeswax and soybean oil (BW/SO‐SLNs). These SLNs impart phase‐change latent heat functionality to the emulsion. The thermal protective efficacy of this engineered emulsion for encapsulating Lactobacillus plantarum was systematically evaluated. The BW/SO‐SLNs‐stabilized emulsion exhibited a significantly elevated phase transition temperature (51.90°C) compared to that of the blank emulsion (31.58°C), demonstrating enhanced thermal buffering capacity. During spray drying at an inlet air temperature of 140°C, microcapsules incorporating 0.25 wt% BW/SO‐SLNs achieved a probiotic survival rate of 76.07%, markedly higher than the 58.69% observed in the blank group (without BW/SO‐SLNs). This represents an approximately 1.30‐fold improvement in protective efficiency. Furthermore, accelerated thermal stress testing (90°C, 10 min) confirmed superior thermal stability, with viable counts for BW/SO‐SLNs‐loaded microcapsules remaining at 8.19 log CFU/g versus 6.95 log CFU/g for the blank. The results demonstrated that the BW/SO‐SLNs‐stabilized W/W Pickering emulsion significantly enhanced probiotic viability during spray drying and thermal processing through a phase‐change heat absorption mechanism. This approach would provide a promising novel encapsulation strategy for protecting heat‐sensitive bioactive compounds in drying processes.