The rough surface of rice flour noodles was attributed to the swollen, unbroken rice starch granules protruding from the smooth matrix of completely gelatinized starch granules. Rice flour had high gelatinization temperature (73.2 C, as determined by a differential scanning calorimeter) (Puncha-arnon & Uttapap, 2013) and high pasting temperature (93.5 C, as determined by a rapid visco analyzer) (Wandee et al., 2014); therefore, some granules still remained in granular form after steaming. The rougher surface of noodles when 20% of rice flour was replaced with retrograded debranched starch was likely due to the low ability of retrograded debranched starch to absorb water. Less moist retrograded debranched starch particles would impede heat transfer to the rice starch granules, and hence reduce the extent of rice starch gelatinization. Also, small pores that appeared on the noodle surface were possibly caused by a difference in water-holding capacity of the two components in the steamed noodle sheet. Pores were generated in the high water holding areas when the noodle