Physical and Water Absorption Characteristics of Some Improved Rice Varieties

A peleg modeling of water absorption in cold plasma-treated Chickpea (Cicer arietinum L.) cultivars

Plasma processing appears to be the mainstay of food preservation in the present day due to its effectiveness in controlling microorganisms at low temperatures. Legumes are usually soaked before cooking. Six chickpea varieties (Kripa, Virat, Vishal, Vijay, Digvijay, and Rajas) were soaked in distilled water at room temperature, and Peleg model was fitted after plasma treatment. Cold plasma treatment was used at 40, 50 and 60 Watt with exposure times of 10, 15 and 20 min. K₁ (Peleg rate constant) consistently decreased from 32.3 to 4.3 × 10^-3 (h % - 1) for all six chickpea cultivars, indicating an increased water absorption rate with increasing plasma power and treatment time. It was lowest in 60 W 20 min plasma treatment in Virat cultivar. K₂ (Peleg capacity constant) ranged from 9.4 to 12 × 10^-3 (h % - 1) for all six chickpea cultivars. Thus, plasma treatment showed no effect on water uptake capacity (K₂), as it did not increase or decrease consistently with increasing plasma power and treatment time. Fitting the Peleg model successfully revealed the correlation between the water absorption of chickpea cultivars. The model fit ranged from R² ≥ 0.9873 to 0.9981 for all six chickpea cultivars.

A transcriptional regulator that boosts grain yields and shortens the growth duration of rice

Complex biological processes such as plant growth and development are often under the control of transcription factors that regulate the expression of large sets of genes and activate subordinate transcription factors in a cascade-like fashion. Here, by screening candidate photosynthesis-related transcription factors in rice, we identified a DREB (Dehydration Responsive Element Binding) family member, OsDREB1C, in which expression is induced by both light and low nitrogen status. We show that OsDREB1C drives functionally diverse transcriptional programs determining photosynthetic capacity, nitrogen utilization, and flowering time. Field trials with OsDREB1C-overexpressing rice revealed yield increases of 41.3 to 68.3% and, in addition, shortened growth duration, improved nitrogen use efficiency, and promoted efficient resource allocation, thus providing a strategy toward achieving much-needed increases in agricultural productivity.

Chewing differences in consumers affect the digestion and colonic fermentation outcomes: In vitro studies

It is important to understand variability in consumer chewing behavior for designing food products that deliver desired functionalities for target consumer segments. In this study, we selected 29 participants, representing...

DEM modelling of swelling of grains

Swelling of grains due to water absorption is ubiquitous in many natural materials and industrial products. Hence, a thorough understanding of grain swelling is of great scientific importance. An experimental investigation can only provide limited information, whereas great insight could be gained from numerical modelling, rigorous numerical models for describing particle swelling are essential. Thus, the objective of this study is to develop and validate a discrete element method (DEM) model for swelling of grains. A first order kinetic model was introduced to describe the swelling of a single grain, and subsequently implemented into the DEM code LIGGGHTS. Model validation was performed by comparing the time evolution of the expansion of a packed bed made of super absorbent polymer (SAP) particles obtained numerically and experimentally. It was demonstrated that the developed model can accurately predict the bed expansion. The validated model was then used to investigate the effect of material properties on the swelling behaviour using rice and SAP as the model materials. It is shown that the swelling depends significantly on material properties, as expected; the expansion of the powder bed made of rice is much lower than that of SAP. The developed model could be further advanced to study consequences of swelling phenomena in granular materials, such as segregation and heat generation.

Grain Dimension, Nutrition and Nutraceutical Properties of Black and Red Varieties of Rice in India

Traditional colored rice varieties in India are the source of carbohydrates, phytochemicals and minerals. They facilitate the growth of probiotics in intestine and protect human from many chronic diseases. The present study investigated the nutritional properties such as total sugars, digestible sugars, resistant sugars, hydrolysis index, glycemic index and total proteins of thirteen colored varieties of rice in India. Nutraceutical properties like anti diabetic and prebiotic activity were investigated by standard methods. Chak hao poreiton and mappillai samba grains were 6.3 mm in length. Lowest length of 5.1 mm was recorded in 60 m Kuruvai. Among the rice varieties, mappillai samba has high concentration of digestible starch of 91% and Chak hao poreiton had low concentration of 62%. Resistant starch was 38% in Chak hao poreiton and 8% in mappillai samba. Lowest glycemic index of 52 and 53 were recorded in karuthakar poha and Chak hao poreiton respectively. Anthocyanin extracted from Chak hao poreiton inhibited 24% of human pancreatic α-amylase activity. It significantly increased the probiotic number from 0.15 CFU/mL to 1.95 CFU/mL. The study revealed that the black rice variety, Chak hao poreiton was rich in resistant starch and exhibited low glycemic index. The anthocyanins from Chak hao poreiton possessed significant antidiabetic and prebiotic activity. Molecular docking studies revealed the interaction of anthocyanin with pancreatic α-amylase, β-glucosidase and GLUT1.

Effect of Parboiling Conditions on Physical and Cooking Quality of Selected Rice Varieties

Most locally cultivated rice varieties in Ethiopia have low physical (low head rice yield, high broken rice yield, and high percentage of chalkiness) and cooking qualities (low water uptake ratio and swelling ratio). Parboiling, a process which involves soaking, steaming, and drying, has been identified as a key technique to improve cooking and milling quality of rice. The current study is aimed at elucidating the effect of parboiling on physical and cooking qualities of three rice varieties (Gumara, Edget, and Narica4) collected from Fogera National Rice Research and Training Center, Amhara region, Ethiopia. Each rice variety was subjected to different soaking temperatures (40°C, 50°C, 60°C, 70°C, and 80°C) and steaming time (10, 20, 30, 40, and 50 minutes). The treatment effect results indicated that parboiling has a significant effect (P < 0.05) on head rice yield and percentage of broken rice with increased soaking temperature and steaming time as compared to the control. For instance, percent head rice yield increased as soaking temperature (from 40 to 80°C) and steaming time (from 10 to 50 min) increased: for Gumara, from 4.07 to 93.6%, for Edget, 9.47 to 96.53, and from 3.20 to 91.67 for Narica4. Percentage chalkiness had decreased as soaking temperature and steaming time increased: 97.33% to 0.00% for Gumara, 97.80% to 0.00% for Edget, and 100.00% to 0.13% for Narica4 as compared to 100% for control of all varieties. The minimum cooking time was identified as 16-23 min for Gumara, 16-23 min for Edget, and 15-20 min for Narica4 rice varieties. The result of the present study clearly showed that parboiling with high soaking temperature and steaming time increased the head rice yield, water uptake ratio, decreased percentage chalkiness, and enhanced the overall quality of the rice varieties.

Empirical characterization of hydration behavior of Indian paddy varieties by physicochemical characterization and kinetic studies

Temperature is an important factor in the determination of hydration kinetics in paddy, and it varies with variety. To understand this hydration behavior, the current study analyses the hydration kinetics of 12 different paddy varieties of India that were exposed to different soaking temperatures. The protein content of the paddy samples was found to be in the range of 6.13 to 9.19%; whereas, starch content was between 67.79 and 84.88%. The physicochemical composition of paddy varieties as well as variation in time-temperature of hydration was found to be decisive in ascertaining the hydration behavior. An increased hydration rate was observed with increasing hydration temperature as well as with higher amylose content of paddy. Among the varieties studied, the ratio of amylose to amylopectin was between 0.37 and 0.77. For all samples, the gelatinization temperature was in the range of 65.60 to 83.10 °C, which in turn was negatively correlated with amylose content, and influenced the hydration behavior of paddy. The optimum time-temperature condition range for hydration for each paddy variety was between 50 and 60°C for 2 to 3.5 hr, depending upon the variety. The activation energy for the paddy samples in this investigation was found to be in the range of 8.70 to 23.10 kJ/mol. The kinetic modeling of hydration was conducted using Peleg's model, with a good fit. The data indicated that with increment in hydration temperature, the rate of hydration was enhanced in all varieties with a decrease in the Peleg's rate constant (K₁ ) and capacity constant (K₂ ). These constants indicate a direct temperature-dependence of water absorption in paddy. PRACTICAL APPLICATION: The hydration of paddy is an important procedure in paddy processing, and across the world, many industries are working on it. Irrespective of the variety, paddy processing globally has remained tricky. Knowledge about the hydration behavior of paddy would enable food processors to better understand the effect of process parameters and to model their experimental setup to obtain the desired physicochemical attributes, as well as process yield. Customers would benefit from adequately processed paddy with better digestibility for which industry would have to invest less in terms of time and resources, thereby making the hydrated paddy more affordable.

Varietal distinctness in physical and engineering properties of paddy and brown rice from southern India

Paddy and brown rice samples were investigated for its physical characteristics which would aid in designing of the equipment and apparatus for processing of grains as sorting, grading and transportation with ease. Significant difference was observed among the different physical properties as geometrical (length, breadth, thickness, equivalent diameter, sphericity, volume, surface area, aspect ratio) gravimetrical (bulk density, true density, porosity etc.) and frictional characteristic such as angle of repose, hygroscopic properties as moisture and water activity and color of paddy and brown rice kernels. Among geometrical properties length was found the maximum in paddy of Mapillai samba (8.21 mm) and Palkudavazhai brown rice (6.34 mm). Among flow properties, Mapillai samba displayed the maximum value for true density of paddy and brown rice varieties respectively. Hardness was reported in the range of (344.1 ± 14.4-594.88 ± 9.5 and 209.31 ± 4.00-395.99 ± 7.05 N) for different varieties of paddy and brown rice cultivars. The color of the brown rice was read as L*, a*, b* where it varied from 36.22 ± 0.71-61.71 ± 0.81, 4.00 ± 0.18-15.29 ± 0.48 and 16.59 ± 0.52-23.81 ± 0.15 respectively. Brown rice varieties can generally be categorized as short bold, long bold and medium slender as per their length and breadth ratio. The significant differences in physical properties of the various cultivars studied, emphasis on varying processing techniques. The physical properties of selected brown rice varieties studied are widely cultivated in southern India, owing to its high nutraceutical potentials.

Quality of ready-to-eat komal chawal produced by brown rice parboiling method

Komal chawal, meaning soft rice, produced by brown rice parboiling of a low amylose rice variety chokuwa, was studied for its physical, physico-chemical, morphological and structural characteristics. The product was produced by soaking the brown rice at 60 °C for 90 min, followed by steaming and air drying to 12.0% (wb). The two steaming conditions used were: (1) open-steaming at atmospheric pressure for 20 min and (2) pressure-steaming at 1 atm (gauge) for 10 min. The three different drying temperatures used were 40, 50 and 60 °C. When soaked in water at 60 °C for 20 min the product attained a hardness value of cooked rice. The extent of changes in the kernel and flour properties as compared to the raw form were affected by the severity of the steaming condition and drying air temperature. The pressure steamed samples exhibited virtually persistent growth in paste viscosity in the profiles obtained from the rapid viscosity analyzer. X-ray diffraction analysis of flours revealed a loss of A-type pattern and formation of feeble peaks of A + V-type mixed patterns in steam-treated samples. Scanning electron photomicrographs showed the loss of the polygonal shape by starch granules during processing. The values of rehydration ratio, equilibrium moisture content for rehydration, sediment volume, extent of color change as denoted by total color difference, and the percent head rice yield were higher in pressure steamed komal chawal samples.

Evaluation of physical properties of rice used in traditional Kyrgyz Cuisine

Eight staple rice cultivars consumed in Kyrgyzstan were evaluated for physical properties in this study. The dimensions of investigated grains correspond to 5.29-6.99 mm for length, 2.52-3.10 mm for width, and 1.88-2.13 for thickness. Equivalent diameter was in range of 3.14 - 3.47 mm, surface area took 25.35-31.90 mm². The sphericity analysis values varied from 0.480 to 0.559, aspect ratio from 0.39 to 0.55, volume of the grain was measured in range from 16.25 to 22.02 mm3, bulk density values were 0.77-0.87 g/cm3, and solid density from 1.17 to 1.41 g/cm3. The porosity of grain was equal to 28.27-39.83%, thousand kernel weight correspond to 19.67 to 27.15 g, rupture force of grain was measured in range of 63.47-155.50 N, color characteristic varied in parameters L*, a* and b*, 37.58-72.19, -0.22-10.17, and 9.65-21.12, respectively. Optimum cooking time ranged from 19.33 to 33.00 min. The water uptake ratios for 30 min of soaking were 1.21-1.28, 1.18-1.45, and 1.14-1.57 for 30, 45, and 60°C, respectively. While the water uptake ratios for 60 min of soaking were 1.22-1.42, 1.19-1.54, and 1.25-1.75 for 30, 45, and 60°C, respectively. Optimal cooking time showed that imported varieties needed lower interval for full grain cooking compared to the local Kyrgyz varieties. It was found that Kyrgyz rice varieties staying more firm after cooking as compared to imported varieties and therefore more suitable for the local traditional dish such as plov.