Physical barrier effects of dietary fibers on lowering starch digestibility

Dietary intervention with low-glycemic response has been suggested to prevent the development of diabetes mellitus. As an antidigestive factor, dietary fiber (DF) becomes a priority for design of foods with low-glycemic response due to its ability to limit starch digestion. In this paper, the physical barrier effects of DF on lowering starch digestibility were discussed in the aspects of viscosity effect, physical embedding, and cell wall integrity. These barrier effects hindered the contact of digestive enzymes with starch matrix, restricted the gelatinization of starch, and maintained the crystallinity and short-range ordered structure, which together decreased the starch digestibility. Finally, strategies for DF to produce low-glycemic foods were illustrated based on the physical barrier mechanisms.