Abstract:As a natural bioactive substance，capsaicin faces obstacles in its development and application due to its strong spicy taste，and the preparation of microcapsules with a slow-release effect can broaden the application of capsaicin.With the carboxyl methyl cellulose sodium and gelatin as wall materials and capsaicin as core material，capsaicin microcapsules were prepared through a complex coacervation method.In addition，the laser particle size meter，ultraviolet-visible spectrophotometer，scanning electron microscope（SEM），Fourier transform infrared spectroscopy （FTIR），and differential scanning calorimeter（DSC） were used to characterize the physicochemical properties of capsaicin microcapsules.Furthermore，the slow-release effect of capsaicin microcapsules in simulated gastrointestinal fluid was investigated by in vitro simulated release，and the release kinetic characteristics were evaluated.The results showed that capsaicin microcapsules contained white solid powder with an average particle size of 40.81 μm，and the microstructure was a heterogeneous sheet or rod；the encapsulation rate and drug load of microcapsules were 87.3% and 43.1%，respectively.The FTIR results showed that capsaicin was completely encapsulated in the microcapsule and did not react with the wall materials.The DSC analysis showed that the thermal stability of capsaicin was significantly improved by microcapsule encapsulation.The in vitro simulated release results showed that the microcapsules were released less in the simulated gastric juice，and the cumulative release rate of 7 h was 32.5%，while the cumulative release rate in the simulated intestinal fluid reached about 80%，indicating good controlled release effect，and the release kinetic model was the Retger-peppas equation.