Effects of frozen storage and thawing conditions on physical properties of glutinous rice: (part 2) rheological 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 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 that natural thawing method would produce softer as well as less sticky glutinous rice products during 60-day frozen storage.