Abstract: Under the condition of polymerized Whey Protein (PWP) as the wall material, CaCl2 solution as the coagulant and tartary buckwheat flavonoid as the core material, the tartary buckwheat flavonoid microcapsules were prepared by the orifice-coagulation bath method. The optimum process parameters were determined as follows: core wall ratio 1:9.24, CaCl2 concentration 1.43%, stirring time 52.23 min, and the microcapsule embedding rate obtained under this condition reached 92.85%.The drug loading, moisture content and glass transition temperature of microcapsules were 9.29 %, 7.10% and 152.06 °C, respectively, indicating that the microcapsules had low moisture content and the glass transition temperature was much higher than the general storage temperature;The results of Scanning Electron Microscope (SEM) showed that the surface of the microcapsules was uniform and porous, and it was in a round spherical state；Infrared spectroscopy analysis showed that the microcapsules did not show the characteristic absorption peaks of free tartary buckwheat flavonoids and wall materials, so no other chemical interactions occurred between the core material and the wall material.;The tartary buckwheat flavonoid microcapsules were stable in the simulated gastric juice, and the release amount was small. When entering the simulated intestinal fluid for 6 h, the core material was completely released, showing a good sustained release property. Microcapsules have a good protective effect on tartary buckwheat flavonoids, which can prevent the destruction of tartary buckwheat flavonoids by gastric juice.The study provides a theoretical basis for the PWP for microencapsulation of tartary buckwheat flavonoids and its application, and lays a foundation for the application of tartary buckwheat flavonoid microcapsules in food.

Key words: Polymeric whey protein, tartary buckwheat flavonoids, microcapsules, sustained release