Stabilization of flaxseed oil pickering emulsion with WPI-fibril/ insoluble fraction of Persian gum hybrid microgels for controlled release of vitamins D3 and E in beverage matrices

This study aimed to develop Pickering emulsions that were with fat-soluble vitamins D 3 and E and stabilized by microgel particles formed through high-pressure homogenization (600 bar, two cycles). Composite gels were prepared through the heat-induced co-gelation of 14 % whey protein isolate (WPI), incorporating 1 % blend of WPI nanofibrils and the insoluble fraction of Persian gum (WPF–IFPG). Emulsions were formulated at pH 3 and 7 using aqueous dispersions containing 1 % total solids and 20 % flaxseed oil with 5 % vitamin blend (vitamin D 3 and α-tocopherol), and then incorporated into skim milk and orange juice. Simulated digestion revealed that mucin-induced flocculation in the oral phase significantly increased droplet size (pH 3: 5.532 → 6.851 μm; pH 7: 3.421 → 4.850 μm) and reduced zeta potential (pH 3: +26.604 → −24.811 mV; pH 7: −38.903 → −27.717 mV). Gastric conditions elevated droplet size (pH 3: 17.061 μm; pH 7: 12.268 μm) and viscosity due to protein aggregation. In the intestinal phase, bile salt-induced lipolysis and elevated pH disrupted interfacial structures, reducing droplet size (pH 3: 12.545 μm; pH 7: 10.070 μm) and viscosity, while enhancing vitamin release (D 3 : 97.411 %; E: 96.703 % at pH 7). Although lipid digestion was initially higher at pH 3, final hydrolysis was more efficient at pH 7 (92.91 %). Vitamin D 3 showed superior release, while vitamin E exhibited greater thermal (88 %) and storage stability (95 %). Sensory scores were higher in orange juice (7.2) after 30 days than in milk (6.5) after 3 days. Both vitamins remained stable after pasteurization and storage. These results demonstrate the efficacy of WPI + WPF–IFPG microgels in stabilizing emulsions and delivering lipophilic bioactives in functional beverages. • WPI + WPF–IFPG microgel particles stabilized flaxseed oil Pickering emulsions and co-encapsulated vitamins D 3 and E. • Oral-phase flocculation and gastric aggregation altered droplet size and surface charge in a pH-dependent manner. • Lipid hydrolysis was significantly higher at pH 7 (92.91 %), enhancing vitamin bioaccessibility. • Vitamin D 3 showed 97.4 % release efficiency; vitamin E retained 95 % stability during storage. • Fortified emulsions improved sensory scores and vitamin retention in milk and orange juice matrices.