单宁酸交联处理对明胶性质的影响

采用单宁酸作交联剂对明胶进行交联改性处理，对其凝胶性、降解性进行分析，制备VB1 微胶囊并确定芯材的释放性能。结果表明，与原料明胶相比，交联明胶形成凝胶的最低浓度基本未发生改变，仍为0.6 % 左右，但是在相同浓度下交联明胶的凝胶强度明显降低。体外降解实验表明，原料明胶和交联明胶在模拟胃液中几乎不发生降解，但在模拟肠液中都发生降解，且交联明胶的降解速度更慢。交联明胶为壁材制备的微胶囊，其芯材在模拟胃液和模拟肠液中有一定的缓释效果。

Effects of Cross-linking Treatment of Tannic Acid on Properties of Gelatin

Gelatin was cross-linked with tannic acid as cross-linking agent. Gel properties and degradation characters of crosslinked gelatin were evaluated. Microcapsules were prepared with cross-linked gelatin as wall material and vitamin B1 as core material. Release characters of core material in microcapsules were analyzed. The results showed that the minimum concentration of cross-linked gelatin to form gel is identical to raw gelatin at about 0.6%. However, the gel strength of cross-linked gelatin is lower than that of raw gelatin at the same concentration. Degradation study in vitro showed that the raw gelatin and cross-linked gelatin are hardly degraded in simulated gastric fluid, but both of them are degraded in simulated intestinal fluid, and the cross-linked gelatin is degraded slower than the raw gelatin. The microcapsules with cross-linked gelatin as wall material show certain slowrelease property in simulated gastric and intestinal fluids.