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

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 porous 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.