Fabrication of sodium caseinate-based emulsions gel with konjac glucomannan and κ-carrageenan for β-carotene protection

KGM addition decreases droplet size and improves uniformity in CAS-based emulsions. • CRG addition transformed the emulsion into gel, improving the system's stability. • The emulsion gel has excellent textural properties and water-holding capacity. • The emulsion gel improved β-carotene storage stability and photostability. This study investigated the effect of κ-carrageenan (CRG) concentration on konjac glucomannan (KGM)/sodium caseinate-based emulsion gels and evaluated their protective effect on β-carotene. Adding CRG induced a sol-gel transition, resulting in structured emulsion gels. Microstructural analysis showed that the synergistic interaction between CRG and KGM facilitated the formation of a denser and more stable gel network, within which oil droplets were uniformly distributed. These structural enhancements enhanced the rheological and textural properties of the gel and increased its water-holding capacity to 98.1%. Furthermore, the gels effectively protected β-carotene during storage and ultraviolet exposure. At 1.5% CRG, 62% of the β-carotene was retained after 15 days of storage, indicating reduced oxidative degradation. Notably, 1.0% CRG provided superior photoprotection, with more than 50% of the β-carotene retained after 8 h of ultraviolet irradiation. Overall, these findings highlight the potential of KGM/CRG emulsion gels as a delivery system for lipophilic nutrients.