Abstract:In this study, a starch microsphere with high content of slowly digestible starch and resistant starch as well as certain grain quality characteristics was constructed, which called energy sustained-release starch microspheres like grain. The effects of different addition amounts of sodium alginate, gellan gum, chitosan and potato starch on the content of slowly digestible starch in the constructed microspheres were investigated, and on this basis, response surface optimization was conducted. The results showed that the content of slow digested starch was 57.88% when the concentration of sodium alginate, gellan gum and chitosan was 0.051, 0.047 mol/L and 0.014 mol/L, respectively, but the content of resistant starch was low. For the microspheres prepared with lauric acid modified potato starch, the slowly digestible starch content was maintained at a high level, while the resistant starch content was greatly increased to 31.49%. Water absorption and expansibility of both two starch microspheres were good, but the pH value of the soup was lower, and the dry matter content and iodine blue value of the soup were also significantly lower than those of rice and millet. In addition, the texture characteristics of the microspheres were similar to millet. The microspheres could be eaten as grain food.