杜仲黄酮酵母微胶囊工艺优化及其缓释特性

Process Optimization and Sustained Release Characterization of Microcapsules of Eucommia ulmoides Flavonoids Encapsulated in Yeast Cells

摘要:

目的 提高杜仲（Eucommia ulmoides）黄酮的稳定性和利用率。方法 以酵母细胞为壁材对杜仲黄酮进行包封，通过单因素结合响应面试验优化微胶囊的制备工艺，研究高温、紫外光照射和长期贮存对微胶囊稳定性的影响，并探究微胶囊在模拟体外消化和食品模拟物体系中杜仲黄酮的释放行为。结果 最佳制备工艺为芯壁质量比1∶3、包埋时间5.9 h、包埋温度45 ℃，此时包埋率为（78.6±0.8）%。微胶囊经高温、紫外光照射和长期贮存后仍具有较高的保留率，在模拟肠液中的释放率显著高于模拟胃液，在体积分数95%乙醇中的释放量显著高于体积分数10%乙醇。在食品模拟物体系中的释放行为均符合Zero-Order和Hixson-Crowell模型（R²>0.90），且Ritger and Peppas模型的K值<0.45，表明扩散方式为菲克扩散。微观形貌结果表明，微胶囊呈椭圆形，表面光滑无裂痕，但经乙醇处理后微胶囊出现明显凹陷和裂痕。结论 酵母细胞包埋杜仲黄酮可显著提高其稳定性和缓释特性。

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.