4 shows an ultrastructure of the surfaces of thermoase- treated bread and the control bread by scanning electron micro- scopy. Many irregularly cellular structures that resembled cork cells were observed on the surfaces of the thermoase-treated bread; however, small amounts of cellular structures were observed on the surfaces of the control bread. These results suggest that the bene- ficial effects of thermoase were related to the enzymatic hydrolysis of proteins in the protein matrix in which starch granules were embedded, leading to reduced interference with the starch phase and the production of a more cellular structure. The resulting structure was assumed to confer soft and high-volume properties to gluten-free rice bread.