Xanthan Gum-Stabilized Sunflower Oil Body Emulsions for β-Carotene Delivery: Preparation, Stability, and Digestion Behavior

In this study, we investigated the encapsulation of β-carotene (β-CE) within sunflower oil body (SFOB) emulsions and examined the role of xanthan gum (XG) in enhancing stability and digestion behavior. The optimal conditions were heating at 45 °C for 15 min, ultrasonic treatment at 270 W for 20 min, and homogenization at 80 MPa, achieving encapsulation efficiency (EE) up to 92%. Furthermore, XG was incorporated to improve structural, oxidative, thermal, and digestive stability. More than 1.5% XG enhanced absolute value of zeta potential (21.3 mV to 23.7 mV), reduced particle size (6.52 μm), and prevented phase separation. XG-coated emulsions exhibited improved stability under heating and oxidative conditions. Additionally, XG enhanced protein digestibility and lipid hydrolysis, as well as the bioaccessibility of β-CE during gastrointestinal digestion. The XG coating also improved photostability under sunlight and UV exposure, with 2% XG emulsions showing the least degradation of β-CE. Moreover, the 2% XG emulsion demonstrated the highest release of free fatty acids (85.75%) and β-CE utilization (80%). These results highlight the potential of SFOB-XG emulsions for the effective delivery of lipophilic bioactives.