High-internal-phase emulsions stabilized by alkali-extracted green tea polysaccharide conjugates for curcumin delivery.

• gTPC-A can stabilize high internal phase emulsions (HIPEs). • The stability of gTPC-A HIPEs under pH, heat and UV irradiation was investigated. • The HIPEs loaded curcumin and protected it from UV radiation and in vitro digestion. • The bioaccessibility of curcumin reached 56.29% in the HIPEs and 8.73% in oil. Exploring the emulsification capabilities of tea polysaccharide conjugates (TPCs) in high-internal-phase emulsions (HIPEs) would further expand the utilization value of TPCs. This study aimed to prepare 0.1–0.5 wt% alkali-extracted green tea polysaccharide conjugate (gTPC-A)-stabilized HIPEs containing 75–87 wt% medium chain triglycerides (MCTs) to investigate their stability, rheology, microstructure, and loading and protective effects on curcumin. The findings revealed that only 0.1 wt% of gTPC-A could stabilize HIPEs containing 85 wt% oil for 30 days. HIPEs had better storage stability in a weakly acidic environment at pH 5.0–6.0 and at temperatures less than 70 °C. HIPEs could load curcumin and protect it from ultraviolet (UV) radiation and in vitro digestion. The half-life of curcumin loaded in HIPEs was 65 h under UV radiation. The curcumin bioaccessibility of HIPEs (56.29 %) was higher than that in MCT (8.73 %). These results provided a theoretical basis for the extensive use of TPCs. [ABSTRACT FROM AUTHOR]