Prevention of textural deterioration in rice cooked with superheated steam during refrigerated storage

This study aimed to compare the physical properties of rice cooked with superheated steam (SHS) with those of rice cooked in an electric rice cooker (RC) as well as evaluate the effects of refrigerated storage (4 °C). Immediately after cooking, SHS-cooked rice showed significantly increased weight and moisture content and decreased yellowness (b*) compared with RC-cooked rice. The hardness of SHS-cooked rice was significantly lower than that of RC-cooked rice after refrigerated storage for 24, 48, and 72 h. SHS-cooked rice showed a densely packed microstructure with smaller cavities, in contrast to the loosely packed structure with larger cavities in RC-cooked rice. Sensory evaluation demonstrated that SHS-cooked rice was significantly softer and less mealy than RC-cooked rice after 24 h of refrigerated storage, resulting in higher overall palatability. The porous structure of SHS-cooked rice might facilitate dispersion of starch molecules within the structure, thereby reducing their aggregation. These findings indicate that SHS cooking prevents the textural deterioration of rice during refrigerated storage by inhibiting starch retrogradation. • Superheated steam (SHS) technology shows excellent results for rice cooking. • SHS rice showed similar hardness as freshly cooked rice after 24 h of refrigeration. • SHS rice was softer than rice cooked using a conventional electric rice cooker. • SHS cooking resulted in a dense microstructure with smaller cavities in cooked rice.