Preparation of high internal phase emulsions based on high-temperature glycation-modified egg white protein: Structural characteristics, stability, and β-carotene bioavailability under multi-parameter regulation

In recent years, freeze-thaw stability of high internal phase emulsions (HIPEs) has gained increasing attention. High-temperature glycosylation-modified proteins have shown to produce stable HIPEs. This study examines the effects of high-temperature glycosylation on egg white protein (EWP) and fructo-oligosaccharides (FO), focusing on how pH and EWP/FO ratios affect the structure of glycosylated EWPs (GEWPs) and HIPEs stability. Specifically, strong alkaline conditions promoted the glycosylation reaction, with the highest DG value at pH 11.0. At pH 5.0, close to the isoelectric point of EWP, GEWPs could not successfully stabilize HIPEs. However, they stabilized HIPEs under other pH conditions, with the best freeze-thaw stability and flocculation resistance when EWP >= FO. At pH 3.0, HIPEs had high viscosity and storage modulus, but phase transitions occurred after freezethaw when EWP <= FO. GEWPs-stabilized HIPEs formed gel structures with elastic properties upon thermal induction. Encapsulation experiments with beta-carotene demonstrated that HIPEs prepared from GEWPs showed potential in DPPH and ABTS+ radical scavenging, improving beta-carotene stability and bioavailability. Our findings show that GEWPs-stabilized HIPEs offer excellent stability, rheological properties, and carrier performance, with enhanced applications through optimized emulsifiers and preparation processes.