Araki, T., Du, K., Ueno, S., Kono, S., Do, G., Maeda, T. 2018 Effects of frozen storage and thawing conditions on physical properties of glutinous rice: (part 2) rheological measurement. ⇒ J-Stage Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers, 35(3), 237-244. Abstract The effects of the freezing process and frozen storage periods on rheological parameters of freshly cooked and freeze-thawed glutinous rice have been investigated. Cooked glutinous rice (cv. Koganemochi) was frozen and stored in a household freezer at -20°C for 1, 5, 10, 30 and 60 days. After steaming and natural thawing processes, creep-recovery test (0.1N, small deformation), texture profile analysis (TPA) test (50% deformation) and the tensile testing (20N, 100% deformation) were performed on one-grain and block-shaped glutinous rice respectively by a rheometer, to measure the rheological parameters of the samples. One-grain samples showed more significant differences with freshly cooked rice in tensile testing, while blockshaped ones showed more in creep recovery tests. There were few significant differences in any fracture characteristics and viscoelastic properties between steaming and natural thawing methods for both block-shaped and one-grain samples in each storage period. The TPA results demonstrated …
Effects of frozen storage and thawing conditions on physical properties of glutinous rice: (part 2) rheological measurement
Effects of frozen storage and thawing conditions on physical properties of glutinous rice: (part 1) ice crystal and color measurement
Araki, T., Du, K., Ueno, S., Kono, S., Do, G., Maeda, T. 2018 Effects of frozen storage and thawing conditions on physical properties of glutinous rice: (part 1) ice crystal and color measurement. ⇒ J-stage Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers, 35(3), 231-236. Abstract The effect of the freezing process and frozen storage periods on the microstructure of cooked glutinous rice has been investigated. Cooked glutinous rice (cv. Koganemochi) was frozen and stored in a household freezer (about -22 °C) during 1, 5, 10, 30 and 60-day storage periods. Its microstructure was observed by using fluorescence staining method and the morphology of ice crystals including equivalent diameter and number was analyzed. Colorimetric measurements were conducted after natural and steaming thawing on samples of each storage period. It was found that average equivalent diameter and number of ice crystals increased with storage period from 5 days, and recrystallization occurred in temperature fluctuation during freezing process and storage affected microstructure of glutinous rice. Moreover, by analyzing the distribution of ice crystals, it was found that most of them are under 10µm in each storage period. Frozen stored glutinous …