Double cross-linked emulsion gels stabilized by flaxseed protein and chitosan: Effects of CaCO3 content on gel properties, stability and curcumin digestive characteristics

In Ca 2+ -induced emulsion gels, rapid Ca 2+ release leads to uneven gel structures, impairing curcumin (Cur) protection and delivery. To overcome this issue, a novel approach combining low-temperature heating (40 °C) and mild acidic environments (pH 6.5) was proposed to gradually releas Ca 2+ from CaCO 3 . This strategy significantly improves the mechanical properties and stability of flaxseed protein (FP)-chitosan (CS) emulsion gels by forming a uniform and dense network structure. At a CaCO 3 concentration of 15 mg/mL, the gel exhibited optimal performance, increasing Cur's photostability and storage stability by 81.3 %, 61.6 %, and 54.8 %, respectively, compared to the control (Cur-oil). Increasing the CaCO 3 concentration also inhibited the release of Cur and free fatty acids, reducing bioaccessibility during in vitro digestion. Overall, this study provides new insights into the stability of bioactive compounds and expands the application of CaCO 3 -induced emulsion gels as delivery systems in the food industry.