High internal phase emulsion system for curcumin delivery co-constructed by wheat gluten amyloid fibrils and Lycium barbarum polysaccharide.

Although various curcumin (Cur) delivery systems have been developed, developing efficient and stable high internal phase emulsions (HIPEs) for Cur delivery systems remains a huge challenge. Here, wheat gluten amyloid fibrils (AF) and Lycium barbarum polysaccharide (LBP) were prepared into the AF-LBP complex. The HIPEs containing AF-LBP complex (AL-HIPEs) was successfully constructed. The formation mechanism of AL-HIPEs was studied. The delivery system of Cur (AL-HIPEs-Cur) was successfully constructed by using AL-HIPEs. The results showed that when pH was at 3 and AF concentrations were 40 mg/mL, the AL-HIPEs had higher viscosity, stability and dense gel network structure. The findings of structural characterization showed that the strong electrostatic interaction between AF and LBP, high hydrophobicity and stable hydrogen bonding were the key factors to boost AL-HIPEs stability. The retention rate of Cur in the emulsion decreased with the increase of pH. The thermal stability, storage stability and light stability of the emulsion were the best at pH 3. The results of in vitro digestion showed that the bioaccessibility of Cur in AL-HIPEs-Cur increased by 28.96 % compared to Cur in oil. This study can provide some valuable suggestions for the efficient delivery of Cur and the improvement of its in vitro bioaccessibility.