Moisture Content Of Paddy Research Articles

Paddy Drying Technologies: A Review of Existing Literature on Energy Consumption

This study explores the existing literature on specific energy consumption (SEC) use for paddy drying and consolidates all relevant data for comparisons across technologies. Energy consumption data for a range of drying technologies are consolidated from published literature and normalized to enable comparison. A large proportion of the source data are generated from operational performance in industrial or laboratory settings, while the remainder is derived from computer simulations. The SEC of paddy drying is driven primarily by technology type; however, operational factors (such as the system size, temperature, and airflow) and external factors (such as the local climate and paddy moisture content) also heavily influence system energy use. The results of our analysis show that the industrial drying technologies explored in this study have an average SEC of 5.57 ± 2.21 MJ/kg, significantly lower than the 20.87 ± 14.97 MJ/kg observed in a laboratory setting, which can potentially be attributed to differences in processing capacity. Multi-stage drying typically has higher energy efficiency when tempering stages are incorporated. The self-circulating design of some drying systems may provide additional opportunities for heat exchange, leading to efficient drying performance without the need for a separate tempering stage. Beyond traditional methods, we have observed a notable shift towards solar-assisted and infrared drying technologies in laboratory settings, reflecting an increasing interest in sustainable and efficient drying solutions. In summary, this review consolidates SEC data for rice drying technologies, analyzes the energy intensity and performance of each drying technology, and identifies data gaps that might be addressed in future research.

Deep-Learning-Based Model Predictive Control of an Industrial-Scale Multistate Counter-Flow Paddy Drying Process.

In practical industrial-scale paddy drying production, manual empirical operation is still widely used for process control. This often leads to poor uniformity in the moisture content distribution of discharged grains, affecting product quality. Model Predictive Control (MPC) is considered the most effective control method for paddy drying, but its implementation in industrial-scale drying is hindered by its high computational cost. This study aims to address this challenge by proposing a deep-learning-based model predictive control (DL-MPC) strategy for paddy drying. By establishing a mapping relation between the inlet and outlet paddy moisture content and paddy flow velocity, a DL-MPC strategy suitable for multistage counter-flow paddy drying systems is proposed. DL-MPC systems are developed using long short-term memory (LSTM) neural networks and trained using datasets from single-drying-stage and multistage drying systems. Simulation and analysis are conducted, followed by verification experiments on a 5HNH-15 multistage counter-flow paddy dryer. The results show that the DL-MPC system significantly improves computational speed while achieving satisfactory control performance. The predicted paddy flow velocity exhibits a smooth variation and matches field data obtained from multiple transition points, confirming the effectiveness of the designed DL-MPC system. The mean absolute error between the predicted and actual paddy moisture content under the DL-MPC system is 0.190% d.b., further supporting the effectiveness of the control system.

EFFECT OF STRAW MOISTURE ON PERFORMANCE OF MULCHER IN PADDY STUBBLE FIELD

Globally, most popularised issue is burning of crop residues which has an adverse effect on the environment and human health. According to the estimates of Sardar Patel Renewable Energy Research Institute (2004), about 72 Mt crop residues are burnt on-farm. Apart from burning, the crop residues have several uses viz., soil mulching, manure, power generation, animal feed etc. Hence, straw mulching in paddy stubble field was studied based on the effect of straw moisture on mulching parameters viz., length of chopped material, cutting efficiency and uniformity of spreading. The moisture content of paddy was taken at intervals after harvesting of crop i.e., 20, 30 and 40 days after harvest. The straw moisture content at these intervals are found to be 15, 19 and 24 percent respectively. The length of chopped material increased linearly with straw moisture content and varied from 15 to 24 cm. There is a decreasing trend of cutting efficiency with increase in straw moisture content and varied from 65 to 86 percent. The uniformity of spreading varied from 79.53 to 94.56 percent and decreased with increase in straw moisture content.

Comparative studies of the effect of processing conditions on cooking and sensory properties of selected rice varieties

Cooking and sensory properties of rice varieties are important quality indices that influence market value and consumer acceptability. The objective of this study was to evaluate the effect of processing conditions on cooking and sensory properties of five rice varieties grown in Nigeria. The rice varieties; FARO 44, FARO 52, FARO 60, FARO 61 and NERICA 8, were processed using four processing parameters at varying conditions [soaking temperature (65-75°C), soaking time (10-16 h), steaming time (20 – 30 min) and paddy moisture content (12-16%)] using response surface methodology. The effect of processing conditions on cooking properties (cooking time, water uptake ratio and elongation ratio) was analyzed using standard procedures. Quantitative descriptive analysis and principal component analysis were used to describe eleven sensory characteristics (uniform appearance, black specks, whitish appearance, yellow colour, brown colour, creamy flavour, typical rice odour, sweet taste, sticky texture, grainy texture and hard texture) of the rice varieties. The cooking time, elongation ratio and water uptake ratio ranged from 12.75 to 51.58 min, 0.91 to 1.94 and 2.21 to 4.95, respectively. The cooking properties differed with respect to rice varieties and processing conditions. The shortest cooking time, longest elongation ratio and highest water uptake ratio varied from one variety to another. It was observed that NERICA 8 had the shortest cooking time (12.75 min) at 65ºC soaking temperature, 16 h soaking time, 20 min steaming time and 16% paddy moisture content while FARO 52 had the highest water uptake ratio (4.95) at 65ºC soaking temperature, 16 h soaking time, 20 min steaming time and 16% paddy moisture content. The maximum elongation ratio (1.94) was observed at 65ºC soaking temperature, 16 h soaking time, 30 min steaming time and 12% paddy moisture content in FARO 60. The sensory properties of the rice varieties were generally characterised as having uniform appearance, whitish appearance, sweet taste, creamy flavour and rice odour. The information on the cooking and sensory properties of the rice varieties would assist rice processors and consumers in selecting rice variety of choice. Key words: Cooking properties, Rice varieties, Processing conditions, Sensory properties

Temporal and spatial representation of temperature and moisture in drying chamber and its impact on vertical vacuum dehumidifying rice seed dryer performance

Population growth is resulting in a daily increase in rice consumption demand. To grow paddy for this expanding population, quality seeds are necessary. The study was conducted to evaluate the performance and estimate the drying cost of the vertical vacuum dehumidifying dryer. The studied dryer consists of four main parts: drying chamber, heating and cooling chamber, compressor and blower. The paddy (BRRI dhan 80) sample sizes were 100, 125 and 150 kg as treatment per batch. In three treatments, the drying chamber temperature was varied from 21.1 to 57.0 °C. Paddy was dried from initial moisture content 21.8 to 10.6%, 21.1 to 12.0% and 20.7 to 11.9% in three treatments within the drying time of 6.0, 6.5 and 7.0 hrs respectively. During the drying process, the relative humidity was differed from 60 to 35%. The rate of drying was found 2.08, 2.12 and 2.01 kghr −1 respectively for 100, 125 and 150 kg per batch. The capacities of the dryer were found 16.66, 19.23 and 21.43 kghr −1 for three treatments respectively. The drying efficiency was found 68.85% (for 100 kg batch), 69.85% (for 125 kg batch) and 66.20% (for 150 kg batch). The drying cost of paddy (Tk./kg) was found 0.71, 0.56 and 0.47 for three treatments respectively. • The performance of the vertical vacuum dehumidifying rice seed dryer was assessed in terms of drying rate, drying capacity, drying efficiency, and drying cost. • The temperatures of different points in the drying chamber were obtained in the range of 44.2–57.0 °C. • The paddy moisture content was reduced to the final moisture content of 10.6–12.0%. • The Vertical Vacuum Dehumidifying dryer meets the requirements of Bangladesh's small-scale farmers in terms of drying efficiency, drying capacity, and drying cost.

Comprehensive Evaluation of Paddy Quality by Different Drying Methods, Based on Gray Relational Analysis

If paddy is not dried in time after harvesting, it very easily becomes moldy, which causes substantial losses. Inappropriate drying methods also affect the quality and safety of paddy when it enters the drying process. In order to select the optimal drying method, paddy with different moisture content was treated with sun drying, mechanical drying, and late harvesting, and the quality indexes of paddy were tested for safe moisture content. The effects of different drying methods on the quality of paddy were analyzed in terms of burst rate, taste value, appearance quality, and pasting characteristics. A paddy quality index system was constructed, and gray relational analysis (GRA) was used to evaluate comprehensively the paddy quality. The results showed that when the moisture content of paddy was 24.4%, the best quality of paddy was obtained after mechanical drying, when the gray relational degree was 0.996. Timely harvesting and mechanical drying can not only reduce the loss of paddy, but can also ensure the quality and safety of paddy.

Drying Capacity Calculator Program for Paddy Using Sun Drying and Flatbed Drying Methods

Studies have been conducted on developing software programs and applications using C language to simulate drying methods particularly in paddy rice. However, these studies focused on the design and simulation of different drying parameters using specific drying methods. Therefore, this project developed a software program calculator as a simple tool on calculating the drying capacity using sun drying and flatbed drying methods. The study used four target moisture content to calculate the drying capacity based on different input parameters on each drying method. Results revealed that the higher the desired moisture content of paddy, the higher the drying capacity obtained in both sun drying and flatbed drying methods. In terms of drying time, result showed that the longer the drying time, the lower the drying capacity of paddy in both drying methods. Furthermore, it was concluded that the program calculator was able to calculate the final weight, drying weight loss, drying time and drying capacity of paddy in both sun drying and flatbed drying methods.

Paddy moisture on-line detection based on ensemble preprocessing and modeling for combine harvester

The on-line detection of paddy moisture content (MC) during harvest has gained increasing interest recently due to its unique role for the control of combine harvester, yield evaluation and post-harvest grain handling operations. However, it is very difficult to achieve good performance under the complex and changeable situation during field harvest. In this study, paddy varieties, paddy flow, feeding types and algorithms were comprehensively considered to optimize the MC detection method. Firstly, an on-line near-infrared sensing system supplemented for grain tank of combine harvester was designed, and spectra were collected under the most common and essential detecting conditions, which including paddy varieties, feeding types and straw effect. Then, ensemble preprocessing, parameter optimization and accuracy test were performed. The best result of all conditions was extreme learning machine (ELM) coupled with the ensemble preprocessing of orthogonal signal correction with savitzky-golay (OSC + SG). The root mean standard error of prediction (RMSEPV) of this method after validation on unknown sample was as low as 1.0791% w.b, and the residual predictive deviation (RPDV) was higher than 3.5646. Stability tests were carried out under conditions of varying feeding types and straw quantities. The results showed that ELM had enough robustness to cope with complex detecting conditions and maintain proper accuracy as the mean value of repeatability, conditions and reproducibility were calculated as 0.0213%, 0.4471% and 0.6868% w.b, respectively. Despite the preliminary feasibility for on-line MC measurement of paddy, the on-line near-infrared sensing system needs to be verified on combine harvester during harvest.

Performance analysis of solar-biomass hybrid heat pump batch-type horizontal fluidized bed dryer using multi-stage heat exchanger for paddy drying

The paddy drying performance of a solar-biomass hybrid heat pump batch-type horizontal fluidized bed dryer (FBD) using a multi-stage heat exchanger was investigated. Drying experiments were performed under two different operating modes: the drying system with heat recovery (FBD-WHR mode) and the drying system without heat recovery (FBD-NHR mode). The FBD-NHR and FBD-WHR reduced the paddy moisture content from 28.52% dry basis (db) to 16.28% db with a mass flow rate of 0.10328 kg/s in 26.76 and 23.68 min, at average temperatures of 69.8 and 70.3 °C, respectively. The average specific energy consumption, specific thermal energy consumption, and specific electrical energy consumption were 8.85, 5.81, and 3.04 kWh/kg, respectively, for FBD-NHR and 7.43, 4.22, and 3.21 kWh/kg, respectively, for FBD-WHR. The average specific moisture extraction rates were 0.19 and 0.24 kg/kWh for FBD-NHR and FBD-WHR, respectively. The average pick-up and exergy efficiencies were 41.3% and 51.0%, respectively, for FBD-NHR and 40.4% and 57.7%, respectively, for FBD-WHR. The improvement potential ranged from 199.5 to 628.7 W for FBD-NHR and from 113.1 to 669.1 W for FBD-WHR, with average values of 295.6 and 247.7 W, respectively. The thermal dryer efficiencies varied from 3.5% to 29.6% and from 3.7% to 40.8% for FBD-NHR and FBD-WHR, respectively, with average values of 16.5% and 21.8%, respectively. Thermal energy savings of approximately 46.7% were achieved by using the FBD-WHR mode.

Optimization of Operational Parameters for Axial Flow Paddy Thresher Using RSM

Post-harvest practices remains significant qualitative and quantitative throughout the paddy value chain despite rising agricultural productivity. When it comes to rice, most losses occur during the harvesting and threshing operations. In optimizing operating variables, the use of response surface methodology (RSM) and complete randomized design (CRD) is effective. This research discusses the application of these approaches to determine the impact of various operational factors on the performance of an axial flow paddy threshers. Three major operating variables, feeding rate, cylinder speed, moisture content, were changed during the paddy threshing. The machine was evaluated using feed rates in the range of 1700 to 1900 kg/h, threshing cylinder speed from 400 to 650 rpm, and crop moisture content 12 to 16% for the crop. Algebraic models were created in Design-Expert software using computer simulation by the least-squares method to optimize the variables. Models for fuel consumption and torque requirement for threshing were developed and represented the three operational parameters. The study found that all three parameters significantly affected fuel consumption and torque requirement at the linear and quadratic levels. Furthermore, the optimum the torque requirement and fuel consumption was 1152.78 Nm and 2.51 l/h, respectively at 12% moisture content of paddy, Which was recorded at feed rate (1703.92 kg/h), cylinder speed (400 rpm). However, no significant change was observed at the level of the interactions.

Exergy analysis and optimisation of an industrial-scale circulation counter-flow paddy drying process

Drying is a process of removing water from products down to a specific moisture content. It is an energy-intensive process widely-used for grain and biomass processing. Because of the complicated thermodynamics and transport phenomena involved in drying, it is challenging to analyse and optimise drying operations. In this study, computer simulations using a transient model are performed to simulate the real-time paddy drying, and analyse the exergy components, exergy efficiency, exergy loss and destruction of industrial-scale drying process under changing drying air temperature (60–80 °C) and flow velocity (0.56–0.83 m/s) and initial moisture content (0.22–0.3 g water/g wet matter) on a circulation counter-flow paddy dryer. Results show our model can predict paddy moisture content and temperature with mean relative deviations of 5.5% and 1.42%, respectively. Exergy efficiency of drying process is specified to be in the range of 28.75–35.68%. Main factor affecting drying rate and energy consumption in high moisture content regions of drying process is drying air flow velocity while that in low moisture content regions is drying air temperature. We also propose control strategy based on two-stage variable ventilation parameters that achieves high exergy utilization level, high drying rate, and high product quality for grain drying.

Development and assessment of cost-benefit parameters of Solar Pv Powered Paddy Thresher

This paper deals with the development, technical and financial analysis of a locally available small size solar photovoltaic DC powered paddy thresher. The threshing machine was developed at Workshop Machinery and Maintenance (WMM) divisional Workshop of Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh during 2021. Locally available materials and 1 hp motor were used to develop the technology. The thresher machine was tested to reduce dependency on diesel and electricity driven threshers in agriculture in Bangladesh. The technical and financial performance was evaluated with the average moisture content of paddy as 17.56% (w.b.). Resulted outputs of the research indicated that the machine threshing capacity was 217 kg/h with a threshing efficiency of 96.04% when threshing drum speed was 475 rpm. The thresher operational cost of per kilogram of threshed paddy for SOPT, MODT and PT were BDT 337, BDT 364 and BDT 372 respectively. However, the developed SOPT was more economically viable compared to the MODT and PT in terms of marginal benefit-cost ratio (1.91) and payback period of the thresher (1.52). The break-even use of SOPT for paddy threshing operation was estimated as 40.20 hr. As compared to MODT, SOPT paddy threshing system is eco-friendly for environment and doesn’t emit CO2 into the atmosphere. However, the SOPT was not familiar to the farmers in Bangladesh. Therefore, there is need of international, regional and national support for adoption and dissemination programs to the small farmers, an entrepreneur or a custom hire service provider in order to popularize this thresher.

Experimental Performance Analysis of a Pilot-Scale Biomass-Assisted Recirculating Mixed-Flow Dryer for Drying Paddy.

A large amount of heat energy is required for paddy drying processes to evaporate water from paddy grains. Currently, fossil fuels are being used as an energy source to heat air during the drying process. However, fossil fuels cause air pollution, climate change, and disruption of ecological balance. In this study, to reduce the dependence on fossil fuels for paddy drying, a pilot-scale biomass-assisted recirculating mixed-flow drying system (PSBA-RMFD) for drying paddy was designed, installed, and tested. In this PSBA-RMFD, the heat energy required for heating the drying air was provided only by biomass. The PSBA-RMFD comprises a biomass furnace, drying column, vibratory feeder, bucket elevator, and blower. This study is aimed at evaluating the performance of the PSBA-RMFD with a drying capacity of 400 kg/h. The performance metrics of the PSBA-RMFD were specific energy consumption (SEC), specific thermal energy consumption (STEC), specific moisture evaporation rate (SMER), thermal efficiency of the PSBA-RMFD, exergy efficiency of the drying section, and improvement potential of the dryer. From the experiments conducted in this study, the values of the aforementioned performance parameters were as follows: 0.806-8.656 kW h/kg of water evaporated; 0.385-4.136 kW h/kg of water evaporated; 0.122-1.308 kg of water evaporated/kW h; 7.82-83.99%; 15.28-25.64%; and 858.90-1355.62 W, respectively. The paddy moisture content was reduced from 20.90% wet basis (initial weight of 400 kg) to 13.30% wet basis (final weight of 364 kg) in 270 min, with an average temperature of 78.15°C and average relative humidity of 8.55%. The percentage of biomass energy used in the drying system was approximately 47.77% of the overall energy. In addition, the payback period of the PSBA-RMFD was 1.9 years.

Performance analysis of natural convection biomass operated grain dryer coupled with latent heat storage medium

In the present investigation, a natural convection dryer has been designed for the grain drying process. The designed dryer consist of a conical biomass burner, rectangular chamber, PCM tray, drying chamber, and an exhaust pipe. This dryer is developed mainly for small-scale farmers in the village area of the under-developed countries, where electricity is not available. In the present study, the performance analysis of the dryer has been investigated for the paddy drying process. During the study, the variations of temperature and exergy in the rectangular chamber, PCM tray, and drying chamber with time have been analyzed. The variations in the moisture content of paddy have also been plotted in the study. During the study, 10 kg of paddy of moisture content 33% was dried to the final moisture content of 14.6%. In this investigation, 7.5 kg of biomass (wood) is burnt in three hours and after 1 h of the initiation of biomass burning, paddy was loaded on the tray.

Modelling drying kinetics of paddy in swirling fluidized bed dryer

Drying kinetic model of paddy at specific drying time under different capacities drying conditions were studied under swirling fluidized bed (SFB) dryer. The drying was performed at capacities of 1, 2, and 3 kg, temperatures of 55 °C, drying time of 45 min, and initial moisture content of 31.23 ± 0.26% (d.b.). Temperature measurements, relative humidity, pressure drop, and moisture content were carried out at 1, 2, 3, 4, 5, 10, 15, 25, 35, and 45 min. The obtained drying data were fitted to six mathematical drying kinetics models. The paddy moisture content was reduced to the final moisture content of 14.04 ± 0.75% (d.b.). In general, for all types of treatment capacity evaluated, the drying rate of a paddy utilizing an SFB dryer decreased as the drying time increased. Among examined models, the linear-plus-exponential model Its novelty that can describe paddy drying kinetics using SFB dryer. Its model considers the effect of drying capacity provided good fitting of the predicted moisture with the determination coefficient (R2) of 0.986676 and root mean square error (RMSE) of 0.039478. Besides, the best model constant and the coefficient was a polynomial type with a determination coefficient (R2) of 1.00, and the root means the square error is close to zero. The results indicate, capacity during the drying significantly affected the drying behavior of paddy using SFB dryer.

Modelling and optimising the impact of process variables on brown rice quality and overall energy consumption

This study aimed to optimise the impact of process variables on brown rice quality (brown rice recovery and head brown rice) and overall energy consumption. The applicability of predictive polynomial regression analysis (PRA) and artificial neural network (ANN) models were evaluated. Process variables [paddy moisture content (12-16%), soaking time (10-16 h), steaming time (20-30 min) and soaking temperature (65-75°C)] were interacted using response surface methodology and their impact on brown rice quality and overall energy consumption were determined. The influence of process variables differs significantly with brown rice recovery and head brown rice. However, a decrease in soaking temperature and paddy moisture content was observed to increase overall energy consumption. ANN shows better predictive accuracy than the PRA model. Optimum conditions that can guarantee maximum quality and minimum overall energy consumption was established at 80°C soaking temperature, 7 h soaking time, 35 min steaming time and 14% paddy moisture content.

Modelling and optimising the impact of process variables on brown rice quality and overall energy consumption

This study aimed to optimise the impact of process variables on brown rice quality (brown rice recovery and head brown rice) and overall energy consumption. The applicability of predictive polynomial regression analysis (PRA) and artificial neural network (ANN) models were evaluated. Process variables [paddy moisture content (12-16%), soaking time (10-16 h), steaming time (20-30 min) and soaking temperature (65-75°C)] were interacted using response surface methodology and their impact on brown rice quality and overall energy consumption were determined. The influence of process variables differs significantly with brown rice recovery and head brown rice. However, a decrease in soaking temperature and paddy moisture content was observed to increase overall energy consumption. ANN shows better predictive accuracy than the PRA model. Optimum conditions that can guarantee maximum quality and minimum overall energy consumption was established at 80°C soaking temperature, 7 h soaking time, 35 min steaming time and 14% paddy moisture content.

Multiobjective optimization of parboiled rice quality attributes and total energy consumption

This study was designed to investigate, model and optimize the effect of process factors (soaking temperature, soaking time, steaming time and paddy moisture content) on rice quality attributes and total energy consumption of a commercially grown rice variety (FARO 60) using response surface methodology. The optimum processing conditions obtained for the rice quality attributes and total energy consumption varies from one another. The milling recovery, head rice yield, white bellies, lightness, colour, and total energy consumption values of the parboiled rice ranges from 68.46 - 72.34%; 67.71 - 71.42%; 0.50 - 4.30%; 22.03 - 33.00; 14.10 - 21.21 and 45.27 - 73.68 MJ, respectively. The second-order polynomial models were observed to be fit in predicting milling recovery, head rice yield, white bellies and total energy consumption with the coefficient of determination (R2) that range from 78.71 to 95.03% while colour and lightness values were not fit with R2 ranging from 24.05 to 52.95%. The multiobjective optimization for desirable parboiled rice quality attributes and total energy consumption showed that universal optimum condition was found at 64°C soaking temperature, 11 h soaking time, 35 min steaming time and 17% paddy moisture content. The approach used and information obtained from this study would be useful for rice processors as a strategic means of minimizing total energy consumption, without compromising its desirable quality attributes.
 Keywords: Multiobjective Optimization; Parboiled Rice Quality Attributes; Total Energy Consumption

Low cost measurement of moisture content in long grain paddy

A method was proposed and assessed for measuring the moisture content of paddy using a moisture inspection card. The effects were investigated of the head space, testing duration and moisture content of paddy on cobalt chloride-coated paper discoloration. The coated paper production process consisted of soaking paper in a solution of cobalt (II) chloride and methyl alcohol and then drying at 60 °C. The experiments using the paddy and coated paper were carried out in a jar with the head space of 25%, 50% or 75%, with the lid closed for 30 or 45 min. The results of the experiment to measure the change of the coated paper in the paddy with moisture content of 10–24% wb showed that the paper color slowly changed from blue to pink with an increase in the moisture content. Evaluation using the CIE color system found that the color value from experiments with a head space of 75% for 30 min was not significantly different from that used with a head space of 50% or 25% for 45 min, though for all head space levels, testing duration of 45 min there was more color than for 30 min with the different moisture contents of paddy. Hence, using a head space of 75% for 45 min produced significantly highest color value, so these conditions would be sufficient to allow the paddy moisture content to equilibrate with the relative humidity in the head space. The L∗, a∗, and b∗ values of the coated paper were converted to RGB values for color image printing to subsequently produce a moisture inspection card, based on the color change of the coated paper. In addition, the moisture inspection card is low cost could be reused, so it would be suitable for use by farmers in rural areas. • This method was very cheap price and can be reused. • Suitable for use by farmers in rural areas and small scale farms. • Preliminary examination of how much moisture content of paddy before deciding to sell.

Physical Properties, Pasting Characteristics and Rheological Behaviour of Paddy Varieties Suitable for Flaking

A study was conducted to find the effect of moisture content on various physical properties of paddy varieties (MTU-1010 and BB-11) suitable for flaking. The range of moisture studied was 11.11% to 28.2% (d.b.) for both the paddy varieties. The bulk density of the paddy increased from 514.76 kg/m3 to 563.62 kg/m3 for MTU-1010 variety and 605.28 kg/m3 to 632.62 kg/m3 for BB-11 variety respectively when the moisture content was increased in the experimental range. The sphericity increased from 0.386 to 0.399 for MTU-1010 variety and 0.448 to 0.458 for BB-11 variety with increase in moisture content. The true density and porosity decreased with the increase in moisture content of paddy. The other physical properties such as test weight, surface area, arithmetic mean diameter, geometric mean diameter and angle of repose increased with the increase in moisture content of paddy. The static coefficient of friction of paddy increased with the increase in moisture content on different surfaces e.g. wood, mild steel, and galvanized iron. The regression equations for all the response variables were significant at P < 0.05 with coefficient of determination, R2 (> 0.90). The amylose content in MTU-1010 and BB-11 variety was found to be 30.23% and 26.32% respectively indicating that high amylose containing paddy varieties are generally used for flaking paddy. Further, the pasting properties of both the paddy varieties revealed higher pasting temperature in paddy variety MTU-1010 than BB-11. The rheological studies highlighted higher storage modulus of brown rice than the polished rice for both the paddy varieties.