Chapter 8: Physical and Mechanical Properties of Rice

Kunze, O. R.; Lan, Yubin; Wratten, F. T.

doi:10.1094/1891127349.008

Cited by 10 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[25] Figure 3 shows the sorption curves of white, brown, and rough rice during absorption and desorption in 0.60 to 0.80 and 0.80 to 0.98 a w ranges in the first 1200 min. Sorption curves obtained from three replicate experiments were almost identical with standard deviation of moisture at the majority of times being less than 0.1% (dry basis).…”

Section: Results and Discussion Sorption Curvesmentioning

confidence: 99%

Moisture Diffusivity in Rice Components During Absorption and Desorption

2011

View full text Add to dashboard Cite

Moisture diffusivity values of different rice kernel components, namely endosperm, bran and husk, are required to solve mathematical models describing absorption and desorption processes. In addition to the rice variety and temperature, the moisture diffusivity also depends on its instantaneous moisture content or water activity (a w ) and whether rice is absorbing or desorbing moisture. This research was undertaken to determine moisture diffusivity values of rough rice components in different a w ranges during absorption and desorption. Experiments were performed to measure sorption rates of different rice forms, including white rice, brown rice, and rough rice kernels. Mathematical models were developed to predict their moisture distribution during moisture sorption processes. These models were solved by finite element method using Comsol Multiphysics 1 simulation program. Moisture diffusivity values of different rice components were calculated and found to be different during absorption and desorption. Diffusivity of rice endosperm was higher during desorption than absorption at a w higher than 0.20 and increased with an increase in a w in 0.20-0.80 a w range. Diffusivity of bran remained almost the same with a w while diffusivity of husk decreased with an increase in a w . Results obtained in this research demonstrated that the moisture diffusivity of different rice components varies significantly with the change in water activity or moisture and should be accounted in the mathematical models.

show abstract

Section: Results and Discussion Sorption Curvesmentioning

confidence: 99%

Moisture Diffusivity in Rice Components During Absorption and Desorption

2011

View full text Add to dashboard Cite

show abstract

“…where μ is the Poisson's ratio, which can be calculated by the equation of Kibar et al [29] as expressed in Table 1, and E is the Young modulus, which is related to the moisture content by the following equation [30] :…”

Section: Stress-strain Analysismentioning

confidence: 99%

Modeling heat and mass transfer–induced stresses in germinated brown rice kernels during fluidized bed drying

et al. 2015

View full text Add to dashboard Cite

A study of stress distribution inside a germinated brown rice (GBR) kernel during drying is important to understand the fissure formation of GBR and hence control the drying process in order to improve the quality of GBR. In this study, a finite element method performed in three dimensions in conjunction with the heat and mass balance of the drying system was developed to describe moisture, temperature and stress distributions inside GBR kernels during fluidized bed drying. The modelling was carried out using the couple of heat and mass transfer and validated with the experimental data at 90-150C.The results of moisture and temperature predictions agreed well with the experiments.During drying, tensile stress occurred at the layers close to surface while compressive stress occurred at the inner portion of a kernel. The tensile and compressive stresses increased to the highest value at about 30 s of drying, corresponding to the highest moisture gradient, and then decreased afterwards. The tensile and compressive stresses were higher at a higher drying temperature. These stress prediction results corresponded Downloaded by [New York University] at 01:36 31 July 2015 2 to the experiments which show more severity of GBR fissuring at higher drying temperatures.

show abstract

“…It is believed that fissure development is closely related to the moisture absorption and desorption which happen when the rice is exposed to different relative humidity (RH) conditions (Kunze & Calderwood, 1985). In order to aid in mitigation of the fissure formation and also for design, modeling and optimization of rice processing it is important to know the relationship between equilibrium moisture content (EMC) of rice and equilibrium relative humidity (ERH) of the surrounding air at a certain temperature, described with sorption isotherms (Furmaniak, Terzyk, Golembiewski, Gauden, & Czepirski, 2009;Iguaz, Rodriguez, & Virseda, 2006;Kunze & Wratten, 1985;Sun, 1999).…”

Section: Introductionmentioning

confidence: 99%