酶解-交联法制备多孔淀粉及其负载红景天苷研究

Preparation of crosslinked porous starch by enzymatic hydrolysis combined with crosslinking modification to encapsulate salidroside

以玉米淀粉为原料,采用α-淀粉酶和糖化酶复合酶解与三偏磷酸钠交联改性相结合的方法制备了一系列具有不同交联度的交联多孔淀粉。通过各种表征手段考察了原玉米淀粉、多孔淀粉和交联多孔淀粉的形态结构和理化性质,并应用于负载红景天苷研究。该方法制备的交联多孔淀粉具有良好的蜂窝状中空结构,有利于淀粉颗粒对目的物质的吸附。相比原淀粉和未交联多孔淀粉,交联多孔淀粉的吸油率有较大提高,对红景天苷的包封率为58.89%。经过交联反应后的交联多孔淀粉不但晶型没有发生改变,还具有更高的总孔面积、平均孔直径和孔隙率值,其分子结构也更加紧凑,更具刚性和更高的糊化温度,说明交联改性提高了多孔淀粉的结构性能。体外释放结果表明载药交联多孔淀粉具有一定的缓释性能,能够提高红景天苷的生物半衰期和生物利用度。

A series of crosslinked porous starch with different crosslinking degree were prepared from corn starch by using compound enzymes of α-amylase and glucoamylase combined with sodium trimetaphosphate as crosslinking agents. The morphological structure and physicochemical properties of corn starch, porous starch and crosslinked porous starch were investigated by various characterization methods and applied to the study of encapsulate salidroside. The crosslinked porous starch prepared by this method had a good honeycomb hollow structure, which was favorable for the adsorption of starch granules to the target substance.Compared with the raw starch and uncrosslinked porous starch,the oil absorption capability of crosslinked porous starch had improved significantly, and the entrapment efficiency of salidroside was 58.89% .The crosslinked porous starch remained the same crystal form of corn starch after crosslinking reaction,and had higher values of total pore area, average pore diameter and porosity. Its molecular structure was more compact, more rigid and had a higher gelatinization temperature.All these results indicated that crosslinking modification enhanced the structural properties of pornus starch.The results of in vitro release indicated that the crosslinked porous starch had a good sustained release effect on salidroside, which could improve the biological half-life and bioavailability of salidroside.