Abstract:Objective The aim of the study is to improve the stability and utilization of Eucommia ulmoides flavonoids.Method Eucommia ulmoides flavonoids were encapsulated with yeast cells as the wall material. The preparation process of microcapsules was optimized by single factor experiments combined with response surface methodology. The effects of high temperature treatment, ultraviolet irradiation, and long-term storage on the stability of microcapsules were studied. Furthermore, the release behaviors of microcapsules in the simulated gastrointestinal tract and food simulants were investigated.Result The optimal preparation process for microcapsules was core-wall mass ratio of 1∶3, encapsulation time of 5.9 h, and encapsulation temperature of 45 ℃, under which the microcapsule encapsulation rate was (78.6±0.8)%. The microcapsules showed a high retention rate after high temperature treatment, ultraviolet irradiation, and long-term storage. The release rate of microcapsules in the simulated intestinal fluid was significantly higher than that in the simulated gastric fluid. Furthermore, the release in 95% ethanol by volume fraction was significantly higher than that in 10% ethanol by volume fraction. The release behaviors in the two food simulants were consistent with Zero-Order and Hixson-Crowell models (R2>0.90), and the K-value of the Ritger and Peppas model was less than 0.45, indicating Fickian diffusion. The microcapsules were ellipsoidal and had smooth surfaces without cracks, while significant dents and cracks appeared after treatment with ethanol.Conclusion The stability and sustained release characteristics of Eucommia ulmoides flavonoids can be significantly improved by encapsulation in yeast cells.
