Preparation and properties of β-carotene-loaded sanxan emulsion gel microcapsules

Sanxan has important application value in the field of bioactive substance delivery. However, the current sanxan emulsion gel method has certain limitations in delivering heat-sensitive lipophilic bioactive substances. In this study, the acid-gelling properties of sanxan were utilized to prepare sanxan emulsion gel microcapsules (SEGMs) by extrusion dripping method. The sanxan Pickering emulsion had a particle size of 298.4 nm and an absolute ζ-potential of 48.6 mV, exhibiting better stability. As the concentration of sanxan increased from 0.5 % to 0.9 %, the hardness of SEGMs prepared with gluconolactone as the fixing solution increased by 104.1 %. SEM results showed that oil droplets in the emulsion gels were uniformly distributed in the network of sanxan gels, resulting in smooth and dense wavy structures. Moreover, the porosity of SEGMs could be adjusted by the concentration of sanxan and the oil phase fraction jointly. The in vitro digestion simulation test indicated that SEGMs had a protective effect on β-carotene in simulated gastric fluid, with a release rate of 0.56 %. In simulated intestinal fluid, SEGMs slowly released β-carotene with a release rate of 66.20 %. The results of this study provide theoretical support for the use of sanxan-based emulsion gels or oleogels as lipophilic nutrient delivery systems.