Computational and numerical modeling of rice hydration and dehydration: A review

Paddy (var. Sworn Masuri) was dried by hot air (50 °C), infrared hot air (4,185 W m−2 radiation intensity and 40 °C) and microwave rotary drum (0.37, 0.78, and 1.23 kW kg−1 power density) to evaluate the most suitable method of drying. Before drying, the paddy grains were soaked in water (60 °C, 6 h) followed by steaming (200 kPa, 10 min) to gelatinize the starch. The drying rate constants, apparent moisture diffusivity (Da), convective mass transfer coefficient (hm), head rice yield (HRY) and the broken percentage were estimated. The X‐ray diffraction analysis and scanning electron microscopy (SEM) of starch granules and outer husk of the dried paddy were carried out. Microwave rotary drum drying (MWD) was found to be faster as compared to hot air drying (HAD) and infrared hot air drying (IRHD). The hm in MWD was found to be 90.76–97.01% higher than HAD and 33.33–78.44% higher than IRHD. The HRY and specific energy consumption in MWD were, respectively, 5.87% and 89.16% lower than HAD. The microwave dried rice showed the lowest crystallinity percentage. The SEM of rice starch obtained by MWD showed cracks and fissures whereas IRHD induced microstructural changes only in paddy husk. Practical applications Rice is a staple food of 90% Asian population. The parboiled paddy is dried in the open sun (2–3 days) and by hot air (6–9 h) on farms and in the rice industry. These are highly laborious and time‐consuming methods. Therefore, the study was undertaken from industry suggestion to develop a cost‐effective microwave‐assisted drying method for parboiled paddy. The microwave rotary drum drying was found to give similar quality rice compared to hot air with a 90% reduction in specific energy consumption. Therefore, traditional open sun and hot air drying can be replaced by microwave rotary drum to save expenses towards the capital costs, energy, labor, and grain handling.

Section: Introductionmentioning

confidence: 99%

Effect of convective, infrared and microwave heating on drying rates, mass transfer characteristics, milling quality and microstructure of steam gelatinized Paddy

Behera

Sutar

2018

“…Bello, Tolaba, and Suarez () analyzed the factors that affect the hydration of rice and modeled this kinetic using the Fick's Second Law of Diffusion. Among the works available in literature, the one that stands out is the Shinde et al () and Shanthilal and Anandharamakrishnan (), which gathered in their work an extensive list of articles devoted to the mathematical modeling of the kinetics of water absorption by rice grains.…”

Section: Introductionmentioning

confidence: 99%

Modeling rice and corn hydration kinetic by Nicolin–Jorge model

Nicolin

Marques

Balbinoti

et al. 2017

This article presents the application of Nicolin–Jorge model in describing the hydration kinetics of rice and corn grains. The model was validated by hydration data of both grains for different hydration temperatures. The results show a satisfactory adequacy of the model to the data, even applying the data to the cylindrical and planar geometries, since the original model was proposed to describe the soybean hydration kinetics, considered spherical. Even as the parameters fitted for both cases have behaved differently depending on the temperature, the model predicted properly the reach of equilibrium moisture for very long hydration times. Practical applications The approach presented in this article is useful in describing the moisture absorption kinetics by rice and corn grains. The model applied fits satisfactorily the experimental data and is applicable when the hypothesis of constant mass transfer coefficient in moisture absorption is not enough to correctly describe the behavior of the kinetic curve of moisture as a function of time for such grains. The proposed approach is applicable to any project that requires prior knowledge of the moisture profile of the grains. The advantage of the model used is the simplicity of the analytical solution obtained and that the model possesses physical grounds, although the grains are considered to be a lumped parameter system, which is an adequate consideration for practical applications.

“…Mathematical models of hydration, either empirical or phenomenological, are important tools to understand and to predict operational conditions. This work uses the empirical model of Peleg (), which is commonly applied to modeling the kinetics of hydration process (Balbinoti et al, ; Borges et al, ; Marques et al, ; Montanuci, Jorge, & Jorge, ; Peleg, ; Shanthilal & Anandharamakrishnan, ; Yildirim, Öner, Bayram, Durdu, & Bayram, ).…”

Section: Introductionmentioning

confidence: 99%

Ultrasound assisted hydration improves the quality of the malt barley

Borsato

Jorge

Mathias

et al. 2019

The purpose of this work was to describe the effect of thermal hydration sonication, and non‐sonication, of ANAG 01 barley grains at 35 and 40°C, to evaluate the malt quality parameters and the water incorporation capacity. The sonication caused an increase in the size of starch granules over time and improved the water incorporation rate. No fragmentation was identified by the application or absence of the ultrasound. The malt quality parameters were compared, and the best characteristics were obtained by the thermal treatments, sonication and non‐sonication, at 35°C, producing malt with most of the quality specifications required by the industry and suitable to be used in the formulation of malting blends. The process was accelerated with the increase in temperature and the application of ultrasound, comparing the moisture gain in 480 and 720 min of hydration. The Peleg model was suitable to describe the hydration kinetics. Practical Applications Using temperatures of 35 and 40°C higher than tipical values in the industrial hydration operation requires less time. The association with the ultrasound is even faster, but can influence the quality of the malt. Therefore, sonication at 35°C temperature was a good alternative to produce malt from barley (ANAG 01).