Rheologicl properties of rice flour with different particle size range

• Main Authors: Jenhui Yang, 楊仁輝
• Other Authors: Lih-Shiuh Lai
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/57117424786800276656

碩士 === 靜宜大學 === 食品營養學系 === 88 === 　　The rheological properties of the TNuS19 and TCW70 rice flours were studied as a function of particle size ranges using rapid-visco analysis as well as steady and dynamic shear rheological measurements. In general, TNuS19 showed higher rheological values than TCW70, possibly due to the higher amylose content in TNuS19 rice flour. The peak viscosity measured through rapid-visco analysis and the storage modulus measured through dynamic rheological test were found to increase with increasing particle size to a certain extent, then decreased with further increase in particle size. Maximum rheological values occurred when the particle size ranged from 75 to 105 m for TNuS19 rice flour, and from 105-150 m for TCW70 rice flour. Steady shear flow behavior results showed that TNuS19 rice flour pastes had a more pronounced shear thinning behavior than TCW70, as indicated by the lower flow behavior index value from power law model simulation. Creep test results indicated that for TNuS19, the rice flour pastes with a particle size range of 75 to 105 m had highest compliance values. However, for TCW70, the rice flour pastes with a particle size range of 105-150 m had lowest compliance values. The creep curves of rice flour pastes were further analyzed using the Peleg model and the 4-parameter Burgers model. It was found that for TNuS19, the Peleg model gave a simpler but better simulation than Burgers model. However, for TCW70, neither model provided satisfactory simulation, possibly due to the highly viscous, but relatively lower viscoelasticity of the TCW70 samples. By mixing the TNuS19 and TCW70 rice flours with different particle size ranges, the rheological properties of the mixed rice flour were also studied. In rapid-visco analysis, the peak viscosity values of the mixed rice flours were found to increase with increasing ratio of TNuS19, the final viscosity and setback values increased with increasing ratio of TNuS19 up to 80% then leveled off, and the breakdown values decreased with increasing TNuS19 ratio, then increased. In creep test, the compliance values were found to decrease with increasing the ratio of TNuS19.