The mechanism underlying reduction in gloss of cooked rice during refrigerated storage

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K16263
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Eating habits
• Research Institution: Gifu University
• Principal Investigator: KATSUNO Nakako 岐阜大学, 応用生物科学部, 助教 (20743892)
• Research Collaborator: NISHIZU Takahisa
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 炊飯米 / 表面構造 / 光沢度 / 澱粉の老化 / 凝集挙動

Outline of Final Research Achievements

Through observations of the surface morphology, the present study investigated the mechanism underlying the reduction in the gloss of cooked rice during refrigerated storage. After 12 h of storage, the gloss of the cooked rice had decreased by approximately 64%. From SEM observations, hills and valleys several hundred nanometers in height or depth had gradually formed on the surface of the cooked rice during this 12-h period of storage, which affected the gloss of the surface. The fractal dimension of the SEM image was calculated and found to decrease during storage. The 17° peak area of XRD and the scattering intensity of SAX of the cooked rice increased during storage. These results suggest that the reduction in the gloss of cooked rice during refrigerated storage was caused by the appearance of hills and valleys on the cooked rice grains because starch had aggregated in the vicinity of the surface.

Free Research Field

食品加工学