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The optimization of hydration temperature and duration were determined in six basmati and non-basmati paddy cultivars varying in grain size, shape, and amylose content based on kinetic parameters and effect of hydration temperature on physical, milling, textural and color attributes. Based on higher R2, lower Chi square and RMSE values, Peleg model fitted more suitably compared to Singh and Kulshrestha model. Hydration process significantly altered geometric, gravimetric and mechanical properties as evident by regression analysis. Physical properties except length and L/B ratio positively correlated with increasing hydration temperature. Head rice yield significantly improved in the hydrated treatments and showed a linear increase with the increase in hydration temperature. Head rice yield significantly correlated with hardness of grain (r = 0.684, p ≤ 0.01). Variable physico-chemical properties of cultivars led to establishment of cultivar specific optimum hydration temperature. Based on improvement in hardness, milling efficiency, head rice yield, color and textural attributes, the optimized temperature emerged as 75 °C for long slender grained cultivars (PB1509, PB1718, PS17) and 80 °C for medium grained cultivars (PD18, KJ, AL). The results revealed that optimum hydration temperature should be cultivar specific to get better output of parboiling process. [ABSTRACT FROM AUTHOR]

High head rice and low chalky grain percentages are key grain quality traits selected in developing rice cultivars. The objectives of this research were to characterize the phenotypic variation of head rice and chalky grain percentages in a diverse collection of rice accessions, identify single nucleotide polymorphism (SNP) markers associated with each of these traits using genome-wide association studies (GWAS), and identify putative candidate genes linked to the SNPs identified by GWAS. Diverse rice varieties, landraces, and breeding lines were grown at the Texas A&M AgriLife Research Center in Beaumont. Head rice percentages (HRP) and chalky grain percentages (CGP) of 195 and 199 non-waxy accessions were estimated in 2018 and 2019, respectively. Phenotypic data were analyzed along with 854,832 SNPs using three statistical models: mixed linear model (MLM), multi-locus mixed model (MLMM), and fixed and random model circulating probability unification (FarmCPU). Significant variations in HRP and CGP were observed between rice accessions. Two significant marker-trait associations (MTAs) were detected on chromosomes 1 and 2, respectively, based on best linear unbiased prediction (BLUP) values in 2018, while in 2019, one SNP was significantly associated with HRP in each of chromosomes 6, 8, 9, and 11, and two in chromosome 7. CGP was significantly associated with five SNPs located in chromosomes 2, 4, 6, and 8 in the 2018 study and ten SNPs in chromosomes 1, 2, 3, 4, 7, 8, 11, and 12 in the 2019 study. The SNPs are located within or linked to putative candidate genes involved in HRP and CGP. This study reports five and ten novel MTAs for HRP and CGP, respectively, while three and five MTAs co-located with previously reported quantitative trait loci for HRP and CGP, respectively. The validation of candidate genes for their roles in determining HRP and CGP is necessary to design functional molecular markers that can be used to effectively develop rice cultivars with desirable grain quality. [ABSTRACT FROM AUTHOR]

Zinc deficiency in rice can lead to reduced nutritional value and taste. This study investigates the potential of zinc oxide nanoparticles (ZnO NPs) as a foliar fertilizer during the jointing stage to improve rice yield, quality, and grain zinc enrichment. Over a two-year field experiment (2019–2020), six doses of ZnO NPs (ranging from 0 to 12 kg hm−2) were applied during the jointing stage (46 days after transplanting). The results revealed that foliar spraying of ZnO NPs increased the number of spikelets per spike and the thousand-grain weight by 7.4% to 9.2% and 4.2% to 7.1%, respectively, resulting in a substantial increase in rice yield. Furthermore, it led to a reduction in chalky white and chalky whiteness by 6.23% to 23.6% and 2.2% to 27.9%. ZnO NPs effectively boosted zinc content in rice grains while decreasing the phytic acid to zinc ratio, indicating improved zinc enrichment. Remarkably, protein and amylose content remained unaffected. These findings underscore the potential of ZnO NPs as a foliar fertilizer to enhance rice production, quality, and zinc enrichment. Further research can explore optimal application strategies and long-term effects for sustainable rice production. [ABSTRACT FROM AUTHOR]

High head rice and low chalky grain percentages are key grain quality traits selected in developing rice cultivars. The objectives of this research were to characterize the phenotypic variation of head rice and chalky grain percentages in a diverse collection of rice accessions, identify single nucleotide polymorphism (SNP) markers associated with each of these traits using genome-wide association studies (GWAS), and identify putative candidate genes linked to the SNPs identified by GWAS. Diverse rice varieties, landraces, and breeding lines were grown at the Texas A&M AgriLife Research Center in Beaumont. Head rice percentages (HRP) and chalky grain percentages (CGP) of 195 and 199 non-waxy accessions were estimated in 2018 and 2019, respectively. Phenotypic data were analyzed along with 854,832 SNPs using three statistical models: mixed linear model (MLM), multi-locus mixed model (MLMM), and fixed and random model circulating probability unification (FarmCPU). Significant variations in HRP and CGP were observed between rice accessions. Two significant marker-trait associations (MTAs) were detected on chromosomes 1 and 2, respectively, based on best linear unbiased prediction (BLUP) values in 2018, while in 2019, one SNP was significantly associated with HRP in each of chromosomes 6, 8, 9, and 11, and two in chromosome 7. CGP was significantly associated with five SNPs located in chromosomes 2, 4, 6, and 8 in the 2018 study and ten SNPs in chromosomes 1, 2, 3, 4, 7, 8, 11, and 12 in the 2019 study. The SNPs are located within or linked to putative candidate genes involved in HRP and CGP. This study reports five and ten novel MTAs for HRP and CGP, respectively, while three and five MTAs co-located with previously reported quantitative trait loci for HRP and CGP, respectively. The validation of candidate genes for their roles in determining HRP and CGP is necessary to design functional molecular markers that can be used to effectively develop rice cultivars with desirable grain quality.

Foliar application of Zinc (Zn) and Iron (Fe) fertilizers is known to be an effective solution to enhance rice grain yield and bio-fortification. The objectives of the current field experiment were to evaluate the effects of the foliar application of 0.5, 1, and 1.5 kg ha−1 of Zn and Fe glycine amino acid chelates and ZnSO4 on rice grain yield, protein, Zn, and Fe content of head rice (Hashemi cultivar) under both in the recommended and ½ of the recommended dose of NPK. The highest increase in the grain yield was recorded at 0.5 kgha−1 Fe-glycine amino acid chelate by about 29.2%. The maximum increase in protein and Zn content of head rice were recorded at 1.5 kg ha−1 of glycine amino acid-Zn chelate by about 10.5 and 22.3%, respectively. The most effective treatment to enhance the Fe content of head rice was the foliar application of 1.5 kg ha−1 of glycine amino acid-Fe chelate by about 32.6%. Interestingly, the foliar application of 1 kg ha−1 Zn-glycine amino acid chelate plus 1 kg ha−1 Fe-glycine amino acid chelate at the plots that received ½ of recommended NPK increased the grain yield, and protein, Zn and Fe content of head rice compared to control by about 7%, 18.5, 7.5, and 26.2, respectively. Therefore, regardless of rates and types, foliar application of Zn and/or Fe could enhance both rice yield, protein, Zn, and Fe content of head rice both in plots that received recommended and ½ of the recommended dose of NPK. [ABSTRACT FROM AUTHOR]

Non -uniform drying and head rice reduction due to non -movement of paddy in common fixed bed dryers is one of the basic problems in rice milling factories. In order to investigate and provide a suitable drying method with the approach of creating uniformity in drying process, reducing losses, and saving energy consumption, a two factorial experiment in completely randomized design (CRD) was used. The factors were the initial moisture content (IMF) of paddy at two levels (16 and 18%) and drying methodat 4 levels (one -way air flow, reverse air flow in 1 hour, 2 hours and 3 hours and then continuation of drying process the same as one -way airflow). The same drying air temperature and air velocity was considered for all treatments. In both moisture treatments, three hours reverse air flow drying has the highest head rice (75.7 -75.86%) and the lowest energy consumption (41 -49 MJ/kg water). The highest energy consumption with the amount of 79 and 67 MJ/kg water was belonging tothe one -way air flow treatment of paddy with high and low IMC (respectively).In one way airflow, dried paddy in 10 cm from the bottom layers of dryer has the lowest amount of head rice (63.65%). In both moisture treatments, the results of mixed layers showed that one hour reverse air flow drying with values of 68.28 -68.68% had the lowest head rice. Also, drying method had no significant effect (P>0.05) on the cooking quality. [ABSTRACT FROM AUTHOR]

Zinc deficiency in rice can lead to reduced nutritional value and taste. This study investigates the potential of zinc oxide nanoparticles (ZnO NPs) as a foliar fertilizer during the jointing stage to improve rice yield, quality, and grain zinc enrichment. Over a two-year field experiment (2019–2020), six doses of ZnO NPs (ranging from 0 to 12 kg hm−2) were applied during the jointing stage (46 days after transplanting). The results revealed that foliar spraying of ZnO NPs increased the number of spikelets per spike and the thousand-grain weight by 7.4% to 9.2% and 4.2% to 7.1%, respectively, resulting in a substantial increase in rice yield. Furthermore, it led to a reduction in chalky white and chalky whiteness by 6.23% to 23.6% and 2.2% to 27.9%. ZnO NPs effectively boosted zinc content in rice grains while decreasing the phytic acid to zinc ratio, indicating improved zinc enrichment. Remarkably, protein and amylose content remained unaffected. These findings underscore the potential of ZnO NPs as a foliar fertilizer to enhance rice production, quality, and zinc enrichment. Further research can explore optimal application strategies and long-term effects for sustainable rice production.

Application of paclobutrazol in rice to reduce plant height is an adaptation strategy to climate change to reduce logging during the incident. Nevertheless, the effect of paclobutrazol application on rice quality is rarely evaluated. This study aimed to evaluate rice quality of four varieties after paclobutrazol application. The research was carried out from February to July 2021 in Sawah Baru Experimental Station IPB, Bogor. Four varieties namely IPB 3S, Inpari 42, Hipa 18, and Tarabas were treated with paclobutrazol (K1 = 0 ppm, K2 = 150 ppm, K3 = 300 ppm, K4 = 450 ppm, K5 = 600 ppm), which was applied through the leaves at booting stage before the flowering. The results showed that paclobutrazol treatment affected the quality of rice, especially the percentage of brown rice, milled rice, head rice, rice shape, and amylose content. Varieties showed different responses to paclobutrazol treatment. The concentration of 150 ppm started to affect the quality of rice, i.e., increasing brown rice in all varieties, milled rice in IPB 3S and Inpari 42, and head rice and amylose content in IPB 3S and Hipa 18; but reduced head rice on the Tarabas and amylose content on Inpari 42. Further research on paclobutrazol residues in rice is needed to ensure food safety. [ABSTRACT FROM AUTHOR]

Conventional parboiled rice requires many components such as boiler, steam pipe and auxiliary devices. To reduce the complexity of the process, in this work, the new method of producing parboiled rice by hot air fluidized bed (HAFB) and microwave-hot air fluidized bed (MWHAFB) was proposed and investigated. In the experiment, the soaked paddy with an initial moisture content of 47 ± 1% d.b. and initial grain temperatures of 32–65 °C were dried at the drying air temperatures of 110–170 °C with microwave powers of 0.8–4.0 W/gwet paddy (1.6–4.0 kW). The superficial air velocity at 4.6 m/s and bed depths of 5 cm (1 kgwet paddy) and 10 cm (2 kgwet paddy) were used. The experimental results showed that the drying time to reach an intermediate moisture content of 20 ± 2% d.b. was shorter with smaller bed depth, higher drying air temperature and higher microwave power. The MWHAFB and HAFB dryings could produce parboiled rice with a complete degree of starch gelatinization as the operating condition was suitable. The head rice quality of parboiled rice produced by MWHAFB and HAFB was not different. The parboiled rice had yellowish white for drying with excluding the tempering and had yellowish brown with including tempering as indicated by whiteness index (WI) with a value of 51–52. The consumption of energy was significantly lower in HAFB than that in the conventional process whilst the energy consumption between MWHAFB and conventional one was relatively comparable. [ABSTRACT FROM AUTHOR]

FARO-44 rice varieties ispoplaramong Nigerian rice farmersbut incidentally has very little postharvest processing information needed to optimally improve the quality of the milled product. This study was, therefore, carried out to determine the optimal conditions for steam parboiling process for increased head rice yield (HRY) andreduced breakage ratio (BR)and also to determine a simulation model for predicting these two quality attributes ofthe milledFARO-44 rice variety. The process variables studied weresoaking temperature (SkT), soaking time (Skt) and steaming time (STt). The SkT was varied between 70oC and 90oC, Sktbetween40 and 50minswhile STtwas varied between 8 to 12hrs.HRYand BR were selected as the quality attributs considered in the optimization as the response variables. The objective of the optimization was to determine the combination of factors that will maximize HRY and minimize BR. At the composite desirability of 0.683, the optimalvalues of SkT, STt and Sktwere 76.99°C, 40.16 minutess and 9.14hours respectively. Under this factor combination, the corresponding values of HRY and BR were88.58%, and 11.26%respectively. These research results are recommended foruse by rice processors to improve the quality attributes of milled rice quality. [ABSTRACT FROM AUTHOR]

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Optimization study was carried out on the parboiling process variables for improving the milling quality of FARO-44 rice variety using Response Surface Methodology (RSM) in Central Composite Design (CCD). The variables studied were initial soaking temperature (IST), soaking time (SKt) and steaming time (STt) including their interactive effects.The range of the input variables studied were 70-90°C, 8-12hrs and 40-50minsfor initial soaking temperature, soaking time and steaming time respectively. For thisstudy, a total of twenty (20) randomized experimental runs comprising one (1) replicate of factorial point, one (1) replicate of axial point (alpha 2.7) and six (6) centre point in the design space. Analyses of variance (ANOVA) were performed on the experimental data sets and models were fitted for all the response variables generated.The result showed that the optimal parboiling variables were, 900C, 46mins and 10 hours,for initial soaking temperature, steaming time and soaking time respectively with their corresponding optimum response 58.7%, 6.7% and 58.1% for Head rice yield (based on parboiled paddy weight), breakage ratio and milled rice colour (based on illumination). The composite desirability is 0.793 which maximized the percentage Head rice yield (HRY) and milled rice colour (MRC) but minimized the percentage Breakage Ratio (BR). [ABSTRACT FROM AUTHOR]

ice storage on high moisture content and temperatures could accelerate aging process. This research studied the effect of temperature and storage time to changes in the milling quality and color of the milled rice. This study used freshly harvested rough rice of IR 64 varieties with a moisture content of 26.73%, storage temperatures consist of room temperature, 40 °C, 50 °C and 60 °C, and storage time of 0, 2, 4, 6, 8, and 10 days. Observations comprise weight loss and a decrease in grain moisture content, and color quality milled rice. The results showed that the temperature and storage time affects weight loss and decrease moisture content of rough rice, milling quality, and color of the milled rice. The higher temperature and the longer storage, the weight loss and the decreasing moisture content of rough rice increases. Freshly harvested rough rice storage at 40 °C after 6 days showed a relatively large weight loss due to damage of rough rice. The yield and quality of milled rice increased with storage time. Rice color was relatively fixed until the 10th days at room temperature and 40 °C, while stored at 50 °C and 60 °C, the yellowing started after the 4th day and 2nd day respectively. Based on SNI 6128: 2008, water content of milled rice entered the category of quality I, head rice yield on category II and III, while the broken grains and grain groats entered in category II, III, and IV. Temperature and storage time recommended for the storage of freshly harvested rough rice was at 40 °C for 6 days. ABSTRAK elama penyimpanan gabah terjadi proses pengusangan yang akan mengubah mutu giling dan warna beras. Penyimpanan gabah pada kadar air dan suhu tinggi dapat mempecepat proses penurunan mutu. Penelitian ini mempelajari pengaruh suhu dan lama penyimpanan terhadap kehilangan berat dan penurunan kadar air gabah, perubahan mutu giling dan warna beras selama penyimpanan gabah kering panen. Suhu penyimpanan yang digunakan adalah suhu ruang, 40 °C, 50 °C, dan 60 °C, sedang lama penyimpanan adalah 0, 2, 4, 6, 8, dan 10 hari. Suhu dan lama penyimpanan mempengaruhi kehilangan berat dan penurunan kadar air gabah, mutu giling dan warna beras. Semakin tinggi suhu dan semakin lama penyimpanan, kehilangan berat dan penurunan kadar air gabah semakin besar. Penyimpanan gabah pada suhu 40 °C setelah 6 hari menunjukkan kehilangan berat yang relatif besar, meskipun terjadi peningkatan rendemen dan mutu giling. Berdasarkan SNI 6128:2008, kadar air beras giling masuk pada katagori mutu I, persentase beras kepala masuk pada katagori mutu II dan III, sedangkan butir patah dan butir menir masuk pada katagori mutu II, III, dan IV. Warna beras relatif tetap sampai 10 hari penyimpanan pada suhu ruang dan pada 40 °C, sedang pada suhu 50 °C mulai terjadi penguningan setelah penyimpanan 4 hari dan pada suhu 60 °C setelah 2 hari. Suhu dan lama penyimpanan yang direkomendasikan untuk penyimpanan gabah kering panen adalah pada suhu 40 °C selama 6 hari.

Rice lodging followed by flooding has negatively detriment on the production, however, scientific evident is still rare. As the incident tends to escalate as the impact of extreme weather, hence, research was conducted in order to evaluate rice production and its quality of two rice genotypes treated with lodging-flooding. The experiment was conducted at Leuwikopo Farm IPB Bogor in July-October 2016 using randomized complete block design using two factors, i.e., variety (Way Seputih and Way Apo Buru) and lodging (no lodged [bending 0-18°], lodged [lodged 38-56°], and lodged with flooded [lodged 76-90°]). Rice hill aged 85 days after transplanting was lodged for 15 days. Results showed that lodged with flooded treatment did not increase yield loss although the plant tended to have sterility 5.59-22.00% higher, grain weight 2.05-35.26% lower, and 0.88-10.66% lower value of rice to unhusked ratio. Grains from the lodged-flooded plant had a number of head rice 13.38-15.78% lower, broken rice 0-24.84% higher, and stimulated germination on 1.33-3.40% grains than lodged-without-flooded. It is important to use rice varieties with stable on milling quality to address the lodged-flooded incident.

Growing food crops to meet global demand and the search for more sustainable cropping systems are increasing the need for new cultivars in key production areas. This study presents the identification of rice traits putatively producing the largest yield benefits in five areas that markedly differ in terms of environmental conditions in the Philippines, India, China, Japan and Italy. The ecophysiological model WARM and sensitivity analysis techniques were used to evaluate phenotypic traits involved with light interception, photosynthetic efficiency, tolerance to abiotic stressors, resistance to fungal pathogens and grain quality. The analysis involved only model parameters that have a close relationship with phenotypic traits breeders are working on, to increase the in vivo feasibility of selected ideotypes. Current climate and future projections were considered, in the light of the resources required by breeding programs and of the role of weather variables in the identification of promising traits. Results suggest that breeding for traits involved with disease resistance, and tolerance to cold- and heat-induced spikelet sterility could provide benefits similar to those obtained from the improvement of traits involved with canopy structure and photosynthetic efficiency. In contrast, potential benefits deriving from improved grain quality traits are restricted by weather variability and markedly affected by G × E interactions. For this reason, district-specific ideotypes were identified using a new index accounting for both their productivity and feasibility. [ABSTRACT FROM AUTHOR]

The knowledge of engineering properties such as gravimetrical properties (1,000 grain mass, bulk density, true density, and porosity), dimensional properties (length, width, thickness, aspect ratio, surface area, geometric mean diameter, and sphericity), frictional properties (angle of repose and coefficient of friction), and aerodynamic properties (drag coefficient and terminal velocity) are necessary parameters related to machine design for different agricultural process operations such as handling, harvesting, threshing, cleaning, conveying, sorting, drying, processing, and storage. India is a vast country and contributes 20% of the total world’s rice production with cultivars ranging from the scented long grain ones to the sticky short grains. The Kashmir valley cultivates mainly short–medium bold varieties as temperate conditions in the valley are not suitable for the cultivation of long grain scented basmati rice. The most steps in cultivation and postharvest processing are manual and the aim of this work is to emphasize which variety sustains the processing steps to produce high yield quality rice for strengthening the economic conditions of the people.

A field experiment was carried out to determine the optimum sowing date and nitrogen (N) level for the scented rice cv. Pusa Sugandh-3. Twelve treatment combinations of 3 sowing dates, viz., 15th, 16th and 18th standard meteorological week (SMW) at an interval of 10 days and 4 nitrogen levels ('0', '40', '60' and '80' kg N ha-1) were tested randomized in split plot design with three replications. Significant highest plant height (98.56 cm), tillers m-2 (333.41), dry matter (98.38 q ha-1), panicles m-2 (310.05), spikelets panicle-1(130.25) and grains panicle-1 (98.55), grain yield (45.2 q ha-1), harvest index (41.20 %), head rice recovery (47.5 %) and B:C ratio (3.03) were recorded for the early sown 15th SMW crop. Among the different nitrogen levels tested significant highest plant height (98.12 cm), tillers m-2 (342.33) dry matter (100.68 q ha-1), panicles m-2 (321.83), spikelets panicle-1(132.83) grains panicle-1 (96.79), grain yield (48.0 q ha-1), harvest index (42.68 %), head rice recovery (44.54 %) and B:C ratio (3.38) were recorded with the application of 80 kg N ha-1.Therefore, the variety, Pusa Sugandh-3 should be sown earlier in season from 15th to 16th SMW and with nitrogen application of 60-80 kg N ha-1 for realizing economically higher grain yield and profit under the temperate climatic conditions of Kashmir valley. [ABSTRACT FROM AUTHOR]

The effects of the plant growth regulator trinexapac-ethyl (TE), conjoined with different seeding rates of rice (Oryza sativa L.) milling yields, were evaluated in Turkey between 2009 and 2010. Two rice cultivars (Osmancık-97 and Karadeniz), three seeding rates (400, 500, and 600 seeds m-2), and four doses of TE (0, 100, 200, and 300 g ai ha-1) were compared. The experiments were designed in a randomized block in factorial ordering with 3 replicates. Quality factors including head, cargo, and total rice milling yields, 1000 grain weight, and lodging score were evaluated. Head rice milling yield was affected significantly; however, no statistically significant difference was seen with respect to cargo rice and total milled rice by TE dose. The effect was predicted to depend on grain weight and lodging, which decreased rice milling yield. Seeding rate did not have a significant impact on milling yields. There was a significant correlation between milling yields (head rice and total milled rice but not cargo rice) and both 1000-grain weight and lodging. A seeding rate of 500 seeds m-2 was the optimum value among all seeding rates, and the highest milling yields were obtained from Osmancık-97. Irrespective of genotype and seeding rate, treatments with 100, 200, and 300 g TE ai ha-1 increased head rice milling yield. All doses of TE reduced 1000 grain weight and lodging. Regression analysis revealed that increasing TE doses raised head rice milling yield. [ABSTRACT FROM AUTHOR]

Abstract: Grain quality traits play an important role in the economic prosperity of commercial rice markets. The objective of our research was to identify candidate molecular markers associated with three grain quality and flowering traits in a collection of elite rice japonica inbred lines evaluated in five U.S. states. Candidate marker effects were associated with the traits mapped within regions reported from previous QTL analyses while several new allelic interactions were also detected. Common markers for each trait were observed across two or more locations, and two-way interactions unique to a single location were also found. Significant genotype × location interactions were detected while broad-sense heritability estimates were low for all characters. All but one selected marker effect was associated with a reduction in apparent amylose content. A reduction in heading date at three locations was observed with one marker as a main effect or as a component of two-way interactions that mapped ∼ 5 cM from the Hd3a flowering locus. The majority of selected effects for head rice were associated with modest to substantial increases in value. Marker loci and their interactions identified in this study highlighted targeted regions for future association studies and marker-assisted breeding efforts of grain quality traits. [Copyright &y& Elsevier]

Abstract: Percent milling yield is an economically important trait of commercial rice because it largely determines the price that farmers receive for their crop. Analyzing 22 trait variables including milling yield, grain dimensions, chemistry and appearance, we identified 43 quantitative trait loci (QTLs) in a long grain japonica by long grain japonica cross. We report one QTL explaining 20% of the variation in brown rice recovery; two QTLs explaining 14% and 13% of the variation in milled rice recovery; and one QTL explaining 14% of the variation in head rice (HR) recovery. QTLs for the proportion of pre-broken brown rice kernels, seed density, amylose content, and kernel whiteness and chalkiness were found in the same region as the HR QTL. QTLs explaining up to 54% of the variation in grain shape measurements were identified and mapped to areas independent from those identified for milling yield. Analyses of grain appearance traits identified two QTLs for chalk in brown rice and one in head rice, and a QTL explaining up to 33% of the variance in green kernel area. Our results confirm previous findings on the multigenically complex nature of milling yield. [Copyright &y& Elsevier]

Abstract: The objective of this study was to accelerate the aging of “Thai jasmine” paddy via the use of a drying process, which consists of high-temperature fluidized bed drying followed by tempering and ventilation. Based on the experimental results it was found that the rice properties after processing, namely, elongation ratio, whiteness, volume expansion, water uptake, solids loss and pasting properties, changed in a similar fashion to those of the naturally aged paddy. The higher drying temperature, higher initial moisture content and longer tempering time significantly affected the aged rice properties. However, the head rice yield of rice undergone thermal processing was significantly lower than that of the naturally aged paddy. The drying temperature of 150°C, initial moisture content of 33% (d.b.) and tempering time of at least 90min were recommended as the most suitable conditions for accelerating the rice aging process. [Copyright &y& Elsevier]

Abstract: This research is a study of parboiling of brown rice using superheated steam fluidization technique. The influence of soaking temperature and time, steaming temperature, and bed depth on qualities of product: head rice yield, white belly, whiteness, and viscosity of rice flour were focused. The experiments were set up at the material initial moisture content of 12.8% dry basis (d.b.), soaking temperatures of 70–90°C, soaking times of 0.5–2.0h., steaming temperatures of 120–160°C, velocity of 3.9m/s and bed depths of 8–12cm. The experimental result showed that gelatinization occurred while product moisture content decreased and final moisture content about 28% d.b. gave the acceptable levels of the whiteness and white belly. The final moisture content lower than 28% and 18% d.b. resulted in the lower percent of head rice yield and whiteness, respectively. Considering white belly, it was found that the white belly decreased with increasing drying time. Additionally, peak viscosity, breakdown viscosity and setback viscosity of rice flour were found lower than those of raw rice. [Copyright &y& Elsevier]

The volatile components of commercially milled head and broken rice samples and the effect of water washing on volatile components were investigated over 30 d of storage at 37°C and 70% relative humidity. Pentanal, pentanol, hexanal, pentylfuran, octanal, and nonanal were the major volatile components identified by gas chromatography-mass spectrometry (GC-MS) analysis in both head and broken rice samples. The concentration of volatile components was greater in broken rice than in head rice and increased significantly during the storage period for both rice types. Water washing was found to be effective in reducing the volatile components for both head and broken rice. [ABSTRACT FROM AUTHOR]

The effects of drying methods and storage time on the aroma and milling quality of the aromatic rice, Khao Dawk Mali 105, stored as whole grains, were investigated in order to define the most appropriate post-harvest treatment for the rice. Among the six drying methods that were used, namely: modified air at 30 and 40 °C, hot air at 40, 50, and 70 °C, and sun-drying, the methods that employed lower temperature appeared to provide higher concentrations of the key aroma compound, 2-acetyl-1-pyrroline, and lower amounts of the off-flavour compounds, n-hexanal and 2-pentylfuran, regardless of the storage time. The sun-drying method yielded contrasting results. Overall, during 10 months storage, as the time increased, 2-acetyl-1-pyrroline concentrations decreased whereas n-hexanal and 2-pentylfuran contents increased. Head rice yield was most clearly affected in the sample dried by hot air at 70 °C, giving a percentage yield slightly less than half of those obtained by the other drying methods. However, no significant variation in the percentages of whiteness was observed among the rice samples obtained from the different drying methods and storage times. [Copyright &y& Elsevier]

A method was developed for the determination of the size and size distribution of rice and the amount of broken rice kernels using flatbed scanning (FBS) and image analysis (IA). The rice was placed on the glass plate of the scanner and covered with a black sheet of paper. A fully automatic procedure was developed using freeware IA software and standard spreadsheet software. The method was tested on parboiled and regular-milled white rice of different varieties and compared to manual analysis by weighing after visual separation of whole and broken kernels and by measuring the length and width of rice kernels using a sliding calliper. The FBS method is fast, easy to use and cheap. It yields the same accuracy and better precision than the more time-consuming manual method. Analysis by FBS-IA takes about 3 min per sample compared to about 30 min for manual analysis. The procedure requires a PC with standard desktop scanner. [Copyright &y& Elsevier]

This study was conducted to determine the relative rate of FFA formation and lipid oxidation of unseparated (head and broken), head, and broken rice and the effect of water washing on the lipid quality of broken rice. A regression model was developed with surface FFA or conjugated diene (CD) content vs. incubation time to determine the rates of FFA formation and lipid oxidation. The surface lipid contents of unseparated, head, and broken rice were 0.40, 0.38, and 0.50% of rice, respectively. FFA formation during storage showed three phases: an initial rapid formation, followed by a period of very little or no formation, and finally a phase of gradual formation. In contrast, CD formation initially showed a slow increase but later increased gradually with storage time. The relative rates of FFA and CD formation of unseparated, head, and broken rice were 0.0028, 0.0027, and 0.0036 and 0.192, 0.188, and 0.377, respectively. Water washing reduced the rates of FFA formation and lipid oxidation of broken rice to 0.0015 and 0.2192 from initial values of 0.0031 and 0.369, respectively. Water washing appears to be a simple and practical means of lowering the rates of FFA formation and lipid oxidation in broken rice. [ABSTRACT FROM AUTHOR]

Fluidised bed paddy drying using superheated steam is a newly alternative approach instead of using the conventional hot air. The mechanism of mass transfer for paddy drying in a range of initial moisture content between 25% and 44.5% d.b. is strongly controlled by internal moisture movement inside the kernel and a two-series exponential equation is suitably used to explain its movement. Drying parameters in the equation are a function of temperature and bed depth. For the paddy quality, head rice yield from the superheated steam drying is more sustainable and has higher values than those obtained from the hot air drying, whereas the colour of white rice becomes darker, making it poorer quality. The percentage of white belly is significantly affected by the initial moisture content. [Copyright &y& Elsevier]

This study investigated the effect of soaking time on the quality of parboiled rice. The paddy was soaked in water at 25 and 80 °C for 15, 30, 45, 60 and 120 min. The soaked paddy was steamed, dried, stored and milled. With increasing soaking time a significant increase in water absorption and milling and head rice yield (hence reduction in broken rice) was observed. A significant difference in milling yield, at the 1% level, was obtained between the raw rice control and the hot soaked parboiled samples. A large reduction in fissured grain was observed after soaking. It is suggested that parboiling fills the void spaces and cements the cracks inside the endosperm, making the grain harder and minimizing internal fissuring and thereby breakage during milling. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-quality cultivar has higher rice quality in dry cultivation in ratoon season. • The accumulation of fatty acids and amino acids assists the rice quality. • Formation of amylopectin optimize crystallites traits to improve rice quality. • The main or diversity of functional groups support rice quality. A field experiment was conducted to explore the impact on rice quality using high-quality (HH) or drought-resistant (HY) cultivars under flooding irrigation (F) or dry cultivation (D) in ratooning rice system by evaluating the metabolism or physicochemical traits of starch, fatty acids, and amino acids affecting grain quality. Compared to FHY and DHY in the main or ratoon season, DHH in ratoon season (DHHR) exhibited a higher appearance and processing quality but lower cooking quality. DHHR mainly synthesized long branch chain amylopectin to construct the crystalline regions with increased crystallinity, crystallites size, interplanar spacing, dislocation density, Asp and Thr in brown and head rice. Also, it accumulated more of C16:0, C18:0, C18:1, C18:2, and C18:3 but reduced glutelin in head rice. An increase in functional groups and diversity was seen in brown and head rice, respectively. Overall, these traits improved the processing, appearance, and pasting quality of DHHR. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted to explore the effects of high-quality (Huanghuazhan, HH), drought-resistant (IR, IRAT109) and drought-susceptible cultivars (ZS, Zhenshan97) under flooding irrigation and dry cultivation (D) on the starch accumulation and synthesis, physicochemical traits of starch granules and rice grain quality at the upper (U) and lower panicle. Under D treatment, IR and ZS had lower rice quality, especially the appearance and cooking quality. DHH-U had the highest appearance, nutritional and cooking quality among all cultivars under D treatment, which could be ascribed to the synthesis of more short-branch chain amylopectin and correspondingly higher starch granule tightness. DHH-U also maintained ordered carbohydrate structure, crystalline regions, and many hydrophilic and hydrophobic functional groups in starch granules before pasting. It could prevent the polymerization of small molecules to avoid the formation of macromolecules after pasting. Overall, these findings may facilitate the improvement of grain quality in rice dry cultivation. • High-quality cultivar outperforms other cultivars in grain quality in dry cultivation. • Formation of short-branched chains of amyplopectin improves rice quality. • Rice dry cultivation leads to highly ordered and crystalline starch granules. • Hydrophilic and hydrophobic functional groups affect rice quality. [ABSTRACT FROM AUTHOR]

The rice (Oryza sativa L.) crop in Arkansas is seeded from late March through early June each year. Farmers need new rice cultivars that not only produce both high rough rice yields and high head rice across this range of seeding dates but do so consistently. Thus, a seeding date study was conducted during 1994 and 1995 at Stuttgart, Arkansas, to study seeding date effects on rough rice yield and head rice and selection for stability. Fourteen rice cultivars were seeded at five dates ranging from late March through mid-June. Kang's yield-stability statistic was used to select cultivars for both high rough rice yields and high head rice as well as stability for both traits. Plant stands from March seedings of each year were significantly lower than for the later seeding dates. Maturity (days to 50 percent heading) was extended at the early seeding dates. Some rice cultivars, such as ‘LaGrue’, had lower and more variable head rice when seeded early. In the June seeding dates each year, ‘Kaybonnet’ produced rough rice yields that were more consistent with yields when planted at the earlier planting dates. ‘Bengal’, ‘Cypress’, ‘Kaybonnet’, and ‘Newbonnet’ were cultivars selected by Kang's stability statistic, which was targeted to select cultivars with stable, high rough rice yields and stable, high head rice. The validity of using Kang's yield-stability statistic for cultivar selection is also evident empirically by the adaptation and wide use of these four cultivars by southern U.S. rice producers. These results indicate that seeding date studies and stability analyses would be useful tools for rice breeders to identify cultivars that will be readily adapted and grown by rice producers. [ABSTRACT FROM AUTHOR]

High rough rice yields are important for the profitable production of rice (Oryza sativa L.). The value of rough rice is determined primarily by head rice (whole milled grains) and broken rice, together referred to as total milled rice. The objective of this study was to optimize selection for rough rice yield, head rice, and total milled rice using path-coefficient analysis and selection indices. Thirty-seven long grain pure lines were grown in an experiment at three Arkansas locations during 1993 and 1994. In another test, twenty-eight F1 hybrids obtained from an eight-parent half diallel of long-grain rices were grown at two locations in Arkansas during 1991. For the pure lines, path analysis revealed that rough rice yield was approximately twice as important in determining total milled rice/ha than head rice. Path analysis for the hybrids revealed that rough rice yield was an even greater component in determining total milled rice/ha. Based on yield components for hybrid rice, panicle density had the largest direct effect determining total milled rice/ha. Filled grain/panicle, grain weight, and head rice, in that order, were secondary, but positive, factors determining total milled rice/ha. A selection index for pure lines based only on selection for head rice was 19.2 percent as effective as selection for total milled rice/ha directly. When selection for total milled rice/ha was based solely on rough rice yield, selection was 82.7 percent as effective as selecting for total milled rice/ha directly. Selection to improve total milled rice/ha should concentrate on increasing both rough rice yield and head rice. Rough rice yield should receive greater priority than head rice in selection strategies. [ABSTRACT FROM AUTHOR]

Brown rice of different long-grain Indica cultivars was polished to variable degree of milling (DoM) to see the difference in proteins and starches characteristics in head (HR) and broken rice (BR). Study revealed differential accumulation of starch, fat and proteins in both HR and BR. Extended DoM of brown rice resulted in a progressive decrease in HR yield and increase in BR yield. The extended DoM caused a decrease in protein and fat content in both HR and BR, whereas; an increase in peak viscosity and final viscosity was observed. On the contrary, the setback viscosity of HR and BR of different rice cultivars was influenced by cultivars and extended DoM. Milled rice from different cultivars milled to 6% DoM showed higher levels of 59 kDa, 54 kDa, 51 kDa, 32 kDa, 31 kDa, 30 kDa, 28 kDa, 24 kDa, 23 kDa, 15 kDa, 13 and 12 kDa PPs, while 28 kDa, 24 kDa, 23 kDa, 15 kDa, 13 kDa and 12 kDa PPs was the least or not observed in BR. The major quantitative changes were observed in 28 kDa, 24 kDa, and 23 kDa PPs. MALDI-ToF/MS analysis revealed the identity of 28 kDa PP as 60S ribosomal protein L10a and glutelin type-D 1 proteins. Whereas, the identity of 24 and 23 kDa PP, respectively was established as pathogenesis-related protein 1 (Oryza sativa Japonica Group) and Oryza sativa 1-Cys peroxiredoxin A. HR showed the presence of highly condensed packaged starch granules with smooth edges, which were tightly imbibed in the proteins matrix. However, the inter-cultivar differences in the starch structure and packaging were also observed. On the contrary, BR revealed lesser accumulation of starch particles with abnormal protein filling and several fissures and cracks in the starch granules of BR of different cultivars. A graphical abstract showing differences in head and broken rice of different long grain Indica rice cultivars. The differences in the protein profile and internal starch granule structure, imbibed in protein matrix, are visible from SDS-PAGE and field emission scanning electron microscopic analysis. Unlabelled Image • Head rice yield decreased with the extended degree of milling (DoM). • Extended DoM caused a decrease in protein content, fat content in both head rice (HR) and broken rice (BR). • Peak viscosity and final viscosity of HR and BR was increased with extended DoM. • MALDI-ToF/MS analysis revealed the absence or least accumulation of glutelin type-D 1 protein in BR. • Storage of 60S ribosomal protein L10a, pathogenesis-related protein 1 and 1-Cys peroxiredoxin A was varied in HR and BR of different cultivars. [ABSTRACT FROM AUTHOR]

The knowledge of engineering properties such as gravimetrical properties (1,000 grain mass, bulk density, true density, and porosity), dimensional properties (length, width, thickness, aspect ratio, surface area, geometric mean diameter, and sphericity), frictional properties (angle of repose and coefficient of friction), and aerodynamic properties (drag coefficient and terminal velocity) are necessary parameters related to machine design for different agricultural process operations such as handling, harvesting, threshing, cleaning, conveying, sorting, drying, processing, and storage. India is a vast country and contributes 20% of the total world’s rice production with cultivars ranging from the scented long grain ones to the sticky short grains. The Kashmir valley cultivates mainly short–medium bold varieties as temperate conditions in the valley are not suitable for the cultivation of long grain scented basmati rice. The most steps in cultivation and postharvest processing are manual and the aim of this work is to emphasize which variety sustains the processing steps to produce high yield quality rice for strengthening the economic conditions of the people. [ABSTRACT FROM AUTHOR]