Abstract: In this study, we used high-amylose maize starch as the raw material to prepare chemically crosslinked starches with different crosslinking degrees employing sodium trimetaphosphate (STMP), phosphorus trichloride oxide (POCl3) or epichlorohydrin (EOH) as the crosslinker. The in vitro fermentation characteristics of the crosslinked starches with fecal microorganisms were investigated and the effect of the crosslinked starches on the intestinal microbiota in vitro was evaluated. Results showed that the fermentation rate of the crosslinked starches decreased with increasing amount of crosslinker used. All these crosslinked starches increased the relative abundance of beneficial bacteria including Roseburia and Ruminococcus. Compared to STMP and POCl3, EOH crosslinking more effectively inhibited the fermentation rate of starch, and promoted butyric acid production.

Key words: crosslinked starch; degree of crosslinking; in vitro fermentation; butyric acid; gut microbiota