微乳过瘤胃胆碱模型探究及体外效果评定

Emulsion-based delivery system for choline: encapsulation and release properties in vitro

通过乳化法构建微乳型过瘤胃胆碱模型(W/O-RPC)并进行体外效果评定,包括:W/O-RPC模型的构建及验证,W/O-RPC模型配方的优化,W/O-RPC模型体外效果评定。结果表明,乳化剂比例、油水比对W/O-RPC氯化胆碱保护率影响极显著(P<0.01),当乳化剂比例高于4.00%、油水比≥55时,W/O-RPC氯化胆碱保护率大于90%;利用体外发酵系统并应用响应面分析法对不同配方的W/O-RPC模型进行优化得到各因素对氯化胆碱释放率的影响顺序为油水比>乳化剂比例,所得最佳配方为乳化剂比例11.01%,油水比82;以瑞信RPC为对照,在人工唾液中W/O-RPC的2 h降解率为9.72%,显著高于瑞信RPC(5.46%,P<0.05),W/O-RPC的24 h降解率为13.18%,与瑞信RPC无显著差异(13.67%,P>0.05),体外发酵系统中W/O-RPC的2 h和24 h降解率分别为44.00%和87.55%,均显著高于瑞信RPC(5.09%和26.10%,P<0.05),瘤胃后消化中W/O-RPC的2 h和24 h降解率分别为28.06%和52.11%,均与瑞信RPC差异显著(12.30%和67.84%,P<0.05)。

This research was conducted to fabricate a new emulsion-based microencapsulation system for rumen-protected choline （W/O-RPC）, and evaluate its release properties in vitro. In particular, the following series of experiments were performed： preparation of W/O-RPC（Expt 1）, formula optimization of W/O-RPC （Expt 2）, and the evaluation of W/O-RPC protective effect in vitro（Expt 3）. Expt 1 was designed to investigate the effects of emulsifier concentration（wt%） and oil-to-water ratio on the protec- tion rate of encapsulated choline chloride. The results showed that the protection rate was relatively stable（〉90%） when the emulsifier concentration was above 4% and oil-to-water ratio was below 5 ： 5. In Expt 2, the Central Composite Design （CCD） and Response Surface Methodology（RSM） were em- ployed to investigate the influence of emulsifier eoncentration（wt%） and oil-to-water ratio on the re- lease properties of choline chloride in W/O-RPC. Response surface and contour were graphed with the value of release property of choline chloride in W/O-RPC as response value. Results were as follows： The order of 2 factors＇ effects on response value was O ： W ratio 〉 emulsifier concentration （wt%）. The optimal emulsifier concentration and oil-to-water ratio were 11.01 wt% and 8 ： 2, respectively. Under this condition, the theoretical release rate of choline chloride in W/O-RPC was 81.01%, and the actual value was（81.65±1.03）%. In Expt 3, an in vitro model simulating were used to evaluate the rate and extent of lipid phase digestion, as the rumen digestion conditions well as the protective effect of W/O-RPC. The results are showed as follows：①After the treatment of artificial saliva （2 hours）, the release rate of W/O-RPC was significantly higher（9.72%, P〈0.05） than that of a commercial product （Reashure RPC）. However, there was no significant difference（P〉0.05） between W/O and Reashure RPC after a 24 h digestion of artificial saliva, the release rate was 13.67% and 13.18%, re- spectively. ② The release rates betw.een two different kinds of RPC were significantly different within the in vitro rumen digestion model （P〈0.05）： when the digestion duration was relatively short （2 h）, the release rate of Reashure RPC and W/O-RPC was 5.09% and 44.00%, respectively; when the digestion duration was increased to 24 h, the digestion rate was also improved to 26.10% and 87.55%, respec- tively, ③ During the post-rumen period, the release rate of Reashure RPC was prominently lower （12.30%） than that of W/O-RPC（28.06%） within a shorter digestion duration（2 h）（P〈0.05）. Nonethe- less, with longer treatment duration（24 h）, the release rate of Reashure RPC was increased to 67.84%, which was significantly higher than that of W/O-RPC （52.11%）.