Milling Quality Research Articles

The Indica Hybrid Rice Containing an OsNRAMP5 Knockout Exhibits Better Adaptability Compared to Its Paternal Parent in the Middle Reaches of the Yangtze River

OsNRAMP5 is a pivotal gene involved in the uptake and transport of cadmium and manganese in rice plants. While the knockout of OsNRAMP5 has significantly decreased cadmium accumulation in rice grains, its impact on the adaptability of indica hybrid rice and its paternal parent still needs to be more adequately explored. This study conducted a three-year field experiment with two of the OsNRAMP5 knockout lines (indica hybrid rice LYDG-1 and its paternal parent DG-1) and their wild-type at four distinct locations in the middle reaches of the Yangtze River. Their adaptability was evaluated by cadmium and manganese accumulation, yield traits, and grain quality. The findings reveal that OsNRAMP5 knockout lines, when grown in mildly and moderately Cd-contaminated paddies, exhibit significantly and stably lower cadmium and manganese accumulation compared with the wild-type. However, there were no significant differences in cadmium and manganese content between LYDG-1 and DG-1. Regarding yield traits, OsNRAMP5 knockout lines did not show a significant reduction compared with the wild-type, except for DG-1 in soil with lower manganese content. For grain quality, the quality of the appearance of OsNRAMP5 knockout lines significantly improved compared with the wild-type. However, the milling quality of DG-1 significantly reduced compared with the wild-type, while this negative impact for LYDG-1 was only observed in soils with lower manganese content. Overall, the indica hybrid rice with an OsNRAMP5 knockout exhibits better adaptability than its paternal parent in the middle reaches of the Yangtze River. These findings offer valuable insights into the potential application and promotion of OsNRAMP5 mutant rice varieties in the middle reaches of the Yangtze River.

Effects of Harvest Time on Grinding Quality, Appearance Quality and Physical and Chemical Quality of Japonica Rice.

Harvest time is very important to rice due to its high correlation to rice yield, eating quality, etc.; however, the impact of harvest time on quality is still unclear. In this study, Nangeng 5718, a japonica rice planted in three regions in Jiangsu Province of China, was used to analyze and compare the milling quality, appearance quality, and physicochemical quality of japonica rice at different harvest times. The results showed that the 1000-grain weight of Nangeng 5718 exhibited no significant change at different harvest times (p > 0.05). The brown rice rate and rice yield at different harvest times were 82.3-85.4% and 66.3-76.1%, respectively. Harvest time had no significant effect on the brown of rice (p > 0.05). However, Nangeng 5718 planted in Nanjing had the highest rice yield at 50 days after heading, which was significantly different from that of rice harvested 65 days after heading (p < 0.05). Nangeng 5718 planted in Huai'an had the highest rice yield at 55 days after heading, which was significantly different from that of rice harvested 60 days after heading (p < 0.05). Harvest time had little effect on the length, width, and thickness of rice. The immature grain rate showed a decreasing trend with the increase in maturity. There were little differences in the protein content of Nangeng 5718 at different harvest times. Nangeng 5718 planted in Nanjing had the highest protein content at 50 days after heading. There was a significant difference between the rice harvested and the rice harvested 60 days after heading (p < 0.05). There were no significant differences between the other two regions (p > 0.05). The accumulated temperature in Nanjing was relatively high, and the RVA curve and RVA eigenvalues of rice varied greatly. The setback value of rice harvested at 50 days was significantly lower than that at 55 days and 60 days (p < 0.05). Rice has good gelatinizing properties. Therefore, timely harvesting and appropriate accumulated temperature could increase 1000-grain weight and rice yield, reduce the immature grain rate, and improve the gelatinization characteristics. Overall, the quality of Nangeng 5718 reached a good level when it was harvested 50 days after heading, with the accumulated temperature reaching 1051 °C. In fact, the harvest time should be chosen flexibly according to the weather conditions. Nangeng 5718 planted in Nanjing should be harvested earlier than 50 days, and rice from Huai'an and Lianyungang was of better quality when the harvest time was 50 days.

Evaluation of Surface Quality and Productivity in Conventional Milling of Copper Beryllium Using Minimum Quantity Lubrication

Copper Beryllium (C17200) has ideal physical and mechanical properties of high fatigue strength, thermal conductivity, and hardness, making the alloy ideal for various high-reliability applications in aerospace, producing inserts and tooling for hazardous environments. However, surface quality and productivity challenges are prominent when processing the alloy due to its properties. This study evaluates the surface quality and productivity in end-milling of Copper Beryllium by analyzing the effects of feed rate, minimum quantity lubrication (MQL) flow rate, and cutting depth on surface roughness (Ra) and material removal rate (MRR). The experiment was designed using the Box-Behnken design, and the samples were machined on a CNC milling machine. The results showed that the MQL flow rate was significant to surface roughness, while the cutting depth was significant to MRR. The optimum parameters were determined as a feed rate of – 60 mm/min, an MQL flow rate of – 80 ml/hr., and a cutting depth of – 0.511 mm, which yielded a surface roughness of 0.12 µm and MRR of 10.19 g/min. The study's novelty is that it considers MQL flow using vegetable oil-based cutting fluid (CF) as an input parameter in machining, offering insight into eco-friendly and cost-effective machining practices. Finally, the significance of the study lies in investigating the machinability of Cu-Be alloy material, addressing challenges related to surface quality and productivity during milling operation.

Study on the influence of geometric parameters of typical titanium alloy power milling tools

Abstract Based on ABAQUS, orthogonal finite element tests were carried out when the number of keyway milling cutter blades was three and four, and the spiral rise angle was 60° and 65°, respectively. The results showed that with the maximum number of blades and spiral rise angle, the milling quality of typical titanium alloy TC4 was greatly improved. The surface roughness decreases, and the effect of spiral lift angle on surface roughness is more significant, which provides a theoretical basis for improving the quality and energy of typical titanium alloy milling tool selection.

Predictive modeling of rice milling degree for three typical Chinese rice varieties using interpretative machine learning methods.

Brown rice over-milling causes high economic and nutrient loss. The rice degree of milling (DOM) detection and prediction remain a challenge for moderate processing. In this study, a self-established grain image acquisition platform was built. Degree of bran layer remaining (DOR) datasets is established with image capturing and processing (grain color, texture, and shape features extraction). The mapping relationship between DOR and the DOM is in-depth analyzed. Rice grain DOR typical machine learning and deep learning prediction models are established. The results indicate that the optimized Catboost model can be established with cross-validation and grid search method, with the best accuracy improving from 84.28% to 91.24%, achieving precision 91.31%, recall 90.89%, and F1-score 91.07%. Shapley additive explanations analysis indicates that color, texture, and shape feature affect Catboost prediction accuracy, the feature importance: color>texture>shape. The YCbCr-Cb_ske and GLCM-Contrast features make the most significant contribution to rice milling quality prediction. The feature importance provides theoretical and practical guidancefor grain DOM prediction model. PRACTICAL APPLICATION: Rice milling degree prediction and detection are valuable for rice milling process in practical application. In this paper, image processing and machine learning methods provide an automated, nondestructive, and cost-effective way to predict the quality of rice. The study may serve as a valuable reference for improving rice milling methods, retaining rice nutrition, and reducing broken rice yield.

Integrated multi-objective optimization of rough and finish cutting parameters in plane milling for sustainable machining considering efficiency, energy, and quality

Plane milling is one of the most prevalent methods in metalworking, recognized for its potential to uncover energy-saving opportunities by optimizing cutting parameters. However, existing research on cutting parameters optimization primarily adopts a phased independent optimization approach, with some studies focusing on rough milling parameters and others on finish milling parameters under predetermined allowances. These research methods lack integrated optimization for both rough and finish milling parameters, leading to suboptimal outcomes. To address this issue, this paper proposes an integrated multi-objective optimization method for both rough and finish cutting parameters in plane milling. The aim is to achieve sustainable machining by considering efficiency, energy consumption, and quality. Specifically, the research accomplishes three key objectives: (1) developing detailed models for the efficiency, energy, and quality of plane milling; (2) presenting an integrated multi-objective optimization model and approach for determining rough and finish cutting parameters in plane milling; (3) conducting a specific case study to validate the effectiveness and feasibility of the proposed model and approach. Experimental findings demonstrated that optimizing cutting parameters in the plane milling process through an integrated approach can reduce processing time by 19.37%, decrease energy consumption by 16.88%, and significantly improve the surface roughness of the workpiece by 27.07% compared to traditional empirical methods. Furthermore, compared to independent optimization schemes, processing time is reduced by 2.99%, energy consumption is lowered by 4.72%, and surface roughness is improved by 13.16%.

Impact of Harvesting Time on Grain Yield, Physicochemical Attributes, and 2-Acetyl-1-pyrroline Biosynthesis in Aromatic Rice

Achieving a consistent grain yield while preserving persistent aroma remains a substantial challenge in aromatic rice production in Bangladesh. To address this challenge, a field experiment was conducted at the agronomy research area of Sher-e-Bangla Agricultural University, Dhaka-1207, between 15 June 2022, and 25 November 2022 (Aman season). This study aimed to evaluate the influence of harvesting time on aromatic rice performance. The experiment, following a randomized complete block design with three replications, involved two factors: factor 1 comprised various rice varieties [Bangladesh Rice Research Institute (BRRI) dhan34, BRRI dhan70, BRRI dhan80, and Tulshimala], and factor 2 comprised three harvesting times [3, 4, and 5 weeks after flowering (WAF)]. Results revealed significant impacts of variety and/or harvesting time on grain yield, physicochemical characteristics, and aroma of aromatic rice. Notably, Tulshimala and BRRI dhan80 exhibited superior milling quality, biochemical properties, and aroma characteristics among the aromatic rice types. BRRI dhan70 and BRRI dhan80 displayed higher grain yield when harvested at 5 WAF. However, Tulshimala and BRRI dhan80 showed superiority in grain 2-acetyl-1-pyrroline (2-AP) concentration when harvested 3 or 4 WAF. Earlier harvesting at 3 and 4 WAF resulted in higher percentages of grain 2-AP (60.22% and 53.96%, respectively) compared with later harvesting at 5 WAF (used as check). In conclusion, varying harvesting times markedly impact the yield, physiochemical characteristics, and aroma of aromatic rice varieties, with earlier harvesting beneficial for aroma retention in Tulshimala and BRRI Dhan80 and later harvesting for increased economic yield in BRRI dhan70 and BRRI dhan80.

Yield, milling quality, rice quality and preferences of superior and specific location rice varieties

Abstract Grain and rice characteristics are a description of the post-harvest quality of rice which is a consideration for farmers, traders, and consumers in choosing rice to be developed and consumed. This study aims to determine the yield, milling quality, rice quality and preference of 5 rice varieties in Indonesia, they were Inpari 32 HDB, Inpari 42 Agritan GSR, Inpari 45 Dirgahayu, Pamelen and Inpari IR Nutri Zinc. The study used a non-factorial Randomized Group Design, rice varieties as treatments, 5 replications. Rice was harvested using 2 methods, namely sickle (manual harvesting) and combine harvester. Determination of Milling Quality, rough rice was milled using a mini electric grain whitener LTJM-2008 then measured the percentage of hulled rice, unhulled rice, bran, and husk. Determination of rice quality, 25 grams of rice samples were sorted manually and measured the percentage of head rice, broken, groats and damaged then determined the grade of rice based on SNI 6128: 2015. The results showed that the rice yield manually and using a combine harvester was different from the potential yield. The milling quality and rice quality of each variety were significantly different (p=0.05%). Rice quality classification based on SNI 6128:2015 shows that Inpari 42 Agritan GSR and Inpari IR Nutri Zinc was included in Medium I, pamelen and Inpari 32 HDB were included in Medium II, and Inpari 45 Dirgahayu was under Medium III. Inpari 32 HDB was the rice variety with the highest preference.

Enhancing grain shape, thermotolerance, and alkaline tolerance via Gγ protein manipulation in rice.

Our findings highlight a valuable breeding resource, demonstrating the potential to concurrently enhance grain shape, thermotolerance, and alkaline tolerance by manipulating Gγ protein in rice. Temperate Geng/Japonica (GJ) rice yields have improved significantly, bolstering global food security. However, GJ rice breeding faces challenges, including enhancing grain quality, ensuring stable yields at warmer temperatures, and utilizing alkaline land. In this study, we employed CRISPR/Cas9 gene-editing technology to knock out the GS3 locus in seven elite GJ varieties with superior yield performance. Yield component measurements revealed that GS3 knockout mutants consistently enhanced grain length and reduced plant height in diverse genetic backgrounds. The impact of GS3 on the grain number per panicle and setting rate depended on the genetic background. GS3 knockout did not affect milling quality and minimally altered protein and amylose content but notably influenced chalkiness-related traits. GS3 knockout indiscriminately improved heat and alkali stress tolerance in the GJ varieties studied. Transcriptome analysis indicated differential gene expression between the GS3 mutants and their wild-type counterparts, enriched in biological processes related to photosynthesis, photosystem II stabilization, and pathways associated with photosynthesis and cutin, suberine, and wax biosynthesis. Our findings highlight GS3 as a breeding resource for concurrently improving grain shape, thermotolerance, and alkaline tolerance through Gγ protein manipulation in rice.

Grain Quality Evaluation of Several Upland Rice Varieties in Indonesia

Abstract High-yielding rice varieties that are adaptive to dry land conditions are the main technological component in efforts to increase rice production also known as upland rice. This study aimed to determine the physical quality, milling quality, physicochemical characteristics, and sensory test of six upland rice new superior varieties namely Inpago 8, Inpago 10, Inpago 12, Inpago Unsoed, Rindang 1 and Rindang 2. The quality analysis was carried out at Rice Quality Laboratory, Indonesian Center for Rice Research (ICRR) in Sukamandi, West Java, Indonesia. Furthermore, rice quality data is compared with the Indonesian National Standard (INS) for paddy No. 0224-1987/SPI-TAN / 01/01/1993 and with INS of rice No 6128:2020. The result showed that upland rice varieties have the criteria of the third class of INS paddy. Out of six varieties, four varieties were categorized as long rice and the rest were medium rice (Inpago 8 and Inpago Unsoed). All varieties were classified as medium shape. According to milling quality, Inpago 12 followed by Inpago 8 has the best yield of brown rice. Meanwhile, the best yield of milled rice was Inpago 12 followed by Inpago 10. All varieties met the percentage of head rice (maximum 75%) and broken rice (maximum 22%) for the second medium class. The Inpago 8, Inpago 10, Inpago 12, and Inpago Unsoed varieties belong to the low to medium amylose group, having a medium gel consistency with a separated and fluffy cooked rice texture character. According to the sensory test findings for cooked rice, there were no differences among any of the kinds in terms of flavor, color, shine, taste and overall evaluation. Based on physical, milling quality and physicochemical characteristics, Inpago 12 is the best variety of all the upland varieties observed.

Implementing multi-trait genomic selection to improve grain milling quality in oats (Avena sativa L.).

Oats (Avena sativa L.) provide unique nutritional benefits and contribute to sustainable agricultural systems. Breeding high-value oat varieties that meet milling industry standards is crucial for satisfying the demand for oat-based food products. Test weight, thins, and groat percentage are primary traits that define oat milling quality and the final price of food-grade oats. Conventional selection for milling quality is costly and burdensome. Multi-trait genomic selection (MTGS) combines information from genome-wide markers and secondary traits genetically correlated with primary traits to predict breeding values of primary traits on candidate breeding lines. MTGS can improve prediction accuracy and significantly accelerate the rate of genetic gain. In this study, we evaluated different MTGS models that used morphometric grain traits to improve prediction accuracy for primary grain quality traits within the constraints of a breeding program. We evaluated 558 breeding lines from the University of Illinois Oat Breeding Program across 2 years for primary milling traits, test weight, thins, and groat percentage, and secondary grain morphometric traits derived from kernel and groat images. Kernel morphometric traits were genetically correlated with test weight and thins percentage but were uncorrelated with groat percentage. For test weight and thins percentage, the MTGS model that included the kernel morphometric traits in both training and candidate sets outperformed single-trait models by 52% and 59%, respectively. In contrast, MTGS models for groat percentage were not significantly better than the single-trait model. We found that incorporating kernel morphometric traits can improve the genomic selection for test weight and thins percentage.

Identifying the Quantitative Trait Locus and Candidate Genes of Traits Related to Milling Quality in Rice via a Genome-Wide Association Study.

Milling quality directly affects production efficiency in rice, which is closely related to the brown rice recovery (BRR), the milled rice recovery (MRR) and the head milled rice recovery (HMRR). The present study investigated these three traits in 173 germplasms in two environments, finding abundant phenotypic variation. Three QTLs for BRR, two for MRR, and three for HMRR were identified in a genome-wide association study, five of these were identified in previously reported QTLs and three were newly identified. By combining the linkage disequilibrium (LD) analyses, the candidate gene LOC_Os05g08350 was identified. It had two haplotypes with significant differences and Hap 2 increased the BRR by 4.40%. The results of the qRT-PCR showed that the expression of LOC_Os05g08350 in small-BRR accessions was significantly higher than that in large-BRR accessions at Stages 4-5 of young panicle development, reaching the maximum value at Stage 5. The increase in thickness of the spikelet hulls of the accession carrying LOC_Os05g08350TT occurred due to an increase in the cell width and the cell numbers in cross-sections of spikelet hulls. These results help to further clarify the molecular genetic mechanism of milling-quality-related traits and provide genetic germplasm materials for high-quality breeding in rice.

MICRO-MORPHOLOGICAL AND PHYSICOCHEMICAL STANDARDISATION OF OPUNTIA ELATIOR MILL. CLADODE: AN UNEXPLORED TRADITIONAL PRICKLY PEAR CACTUS PLANT FROM MAHARASHTRA

Opuntia elatior Mill. (Cactaceae) is a significant medicinal herb In Maharashtra. In Ayurveda, it is referred to as Nagphani, and in English, prickly pear. Its fruits and cladode have long been used to remedy wounds, boils, coughs, fever, inflammation, and asthma. Despite its significant therapeutic potential, there isn't much information about standardised criteria for the species. Consequently, the current project was started to produce a comprehensive report on Opuntia elatior Mill's quality control and standardisation criteria. The current study aimed to highlight this traditional herbal crude, which would make it easier to identify fresh and dried samples using macro, microscopic, fluorescence, and physicochemical parameters in accordance with WHO guidelines. The present study's compilation of botanical characteristics can serve as a benchmark for the herbal medicine industry in identifying adulterations in market samples utilised for manufacturing different herbal remedies. These studies will provide reference information for accurately classifying Opuntia elatior Mill among closely related species within the same genus and family. They will also aid in identifying adulteration in market samples utilised to produce a range of herbal remedies.

Drying and Tempering Influence on the Milling Quality of Parboiled Rice

Rice occurrence and dealings are features of the tradition of Bangladesh’s populace. However, their experience of parboiled paddy for domestic consumption is limited. Proper drying and tempering are very important for maximum milling output. The study was conducted to investigate the drying and tempering influence on the milling quality of parboiled paddy. The sample size of the paddy was 36 kg as per treatment. In the case of T1 (daily 4 hours sun drying) and T2 (daily 5 hours sun drying), 1-hour drying and 1/2 hour tempering were maintained, and for T3 (daily 4 hours sun drying) and T4 (daily 5 hours sun drying), 1-hour drying, and 1-hour tempering were maintained. The temperature of the paddy sample was varied from 18 °C to 42 °C in five treatments. Drying over three days at different time intervals led to reduced moisture content (from 23.42% to 9.24%), resulting in increased kernel hardness for reduced breakage during milling. The highest kernel strength after three days of drying was found to be 50.65 N/m for T4. The relative humidity, day temperature, air flow velocity, and solar radiation varied from 48% to 78%, 24 °C to 29 °C, 0.00 to 0.70 m/s, and 64450 to 108100 lux, respectively. Based on milled rice, the best milling output and head rice recovery were found to be 20.51 kg and 19.80 kg, respectively, for T4. The lowest quantity of broken rice was 0.50 kg found for T1 and T4, respectively. The lowest quantity of loss was 1.10 kg for T2, and the lowest quantity of husk and bran was 6.88 kg for T4. Results showed that among the five treatments, 5 hours of sun drying daily, maintaining the procedure of 1-hour drying and 1-hour tempering until the moisture content is reduced to 10% (T4), is more effective for increasing milling recovery.

Yield and Milling Quality Trade‐Offs in Argentinian Flint Maize

Yield and Milling Quality Trade‐Offs in Argentinian Flint Maize

The Quality of Winter Wheat Grain by Different Sowing Strategies and Nitrogen Fertilizer Rates: A Case Study in Northeastern Poland

The present study was undertaken to determine the effect of different sowing strategies and spring nitrogen (N) fertilizer rates on the technological quality of winter wheat (Triticum aestivum L.) grain in terms of its milling quality, protein complex quality, and enzyme activity (falling number). Winter wheat grain for laboratory analyses was produced in a small-area field experiment conducted between 2018 and 2021 in the AES in Bałcyny (53°35′46.4″ N, 19°51′19.5″ E, NE Poland). The experimental variables were (i) sowing date (early: 6 September 2018, 5 September 2019, and 3 September 2020; delayed by 14 days: 17–20 September; and delayed by 28 days: 1–4 October), (ii) sowing density (200, 300, and 400 live grains m−2), and (iii) split application of N fertilizer in spring (40 + 100, 70 + 70, and 100 + 40 kg ha−1) at BBCH stages 22–25 and 30–31, respectively. A sowing delay of 14 and 28 days increased the bulk density (by 1 and 1.5 percent points (%p), respectively), vitreousness (by 3 and 6%p, respectively), and total protein content of grain (by 1% an 2%, respectively). A sowing delay of 14 days increased grain hardness (by 5%), the flour extraction rate (by 1.4%p), and the falling number (by 3%) while also decreasing grain uniformity (by 1.9%p). In turn, a sowing delay of 28 days increased the wet gluten content of grain (+0.5–0.6%p) and improved the quality of the protein complex in the Zeleny sedimentation test (+1.5%). An increase in sowing density from 200 to 300 live grains m−2 led to a decrease in grain uniformity (by 2.6%p), the total protein content (by 1.5%), and the wet gluten content of grain (by 0.7%p). A further increase in sowing density decreased grain vitreousness (by 1.4%p). The grain of winter wheat fertilized with 40 and 100 kg N ha−1 in BBCH stages 22–25 and 30–31, respectively, was characterized by the highest hardness (64.7), vitreousness (93%), flour extraction rate (73.9%), total protein content (134 g kg−1 DM), wet gluten content (36%), and Zeleny sedimentation index (69 mL).

Thermo-metallo-mechanical based phase transformation modeling for high-speed milling of Ti–6Al–4V through stress-strain and temperature effects

The optimization of machining parameters, tool longevity, and surface quality in High-Speed Milling (HSM) of Ti–6Al–4V relies immensely on understanding the local phase transformation. This study endeavors to build a Finite Element (FE) model capable of forecasting phase alterations during the rapid thermal fluctuations intrinsic to Ti–6Al–4V machining. Dynamic phase transformation models were initially introduced to capture rapid heating and cooling phenomena. Using a user-defined subroutine, the phase transitions predictive models were integrated into the HSM simulation within Abaqus/Explicit. Simulation outcomes unveiled phase transitions primarily occurring within the serrated chip and at the tool-workpiece interface. Notably, during rapid heating, when the cutting speed increased to 350 m/min, the β-phase volume fraction surged from 7.5 to 96.38%. A similar trend was observed with feed rate adjustments (i.e., 0.15–0.25 mm/tooth), where β-phase increased from 7.5 to 67.84%. Rapid cooling facilitated the reversion of the transformed β-phase back into the α'-phase. Finally, some advanced characterization techniques were employed to validate the developed thermo-metallo-mechanical coupled FE model for phase transformation. The simulation results verified by the experimental data promotes a better understanding of phase alteration mechanisms and microstructural evolution in HSM of Ti–6Al–4V. The current research is also beneficial for crucial insights into optimizing the machining conditions and their impact on tool-material interactions and surface integrity.

Fluidized Bed Heat Treatment for Controlling the Lesser Grain Borer (Rhyzopertha dominica) and Sawtoothed Grain Beetle (Oryzaephilus surinamensis) on Paddy cv. Khao Dawk Mali 105

The efficacy of fluidized bed (FDB) heating was studied for controlling stored product insects on rough rice using laboratorial heat-fluidized bed equipment, and the milling quality of rice was later examined. Rough rice cv. Khao Dawk Mali 105 (13% wb) infested with insects was treated with FDB. The lesser grain borer (Rhyzopertha dominica, Fabricius) (internal feeders) had a higher tolerance for heat than the sawtoothed grain beetle (Oryzaephilus surinamensis Linnaeus, external feeders). At a hot air velocity of 3.7 m/s at 55°C for 90 s, the mortality of the lesser grain borer treated by FDB significantly differed (P &lt;0.05) between all stages and from the untreated control. The pulpal stage, as an FDB-tolerant stage of the lesser grain borer, was treated with 55–65 °C for 60–150 s. FDB heat treatment at 55°C for 150 s, 60°C for 90 s, and 65°C for 60 s caused 100% mortality. At a hot air velocity of 3.7 m/s at 40°C for 120 s, the mortality of the sawtoothed grain beetle significantly differed (P &lt;0.05) between all stages and the untreated control. The egg stage, as the FDB-tolerant stage, was treated at 40–50 °C for 60–150 s. FDB heat treatment at 45°C for 150 s and 50°C for 60 s caused 100% mortality. Some of the adults that survived FDB exposure were able to reproduce, but there were significantly less progeny than in the untreated control. Heat FDB slightly affected rice quality in terms of physical and chemical properties. Keywords: Heat, Fluidized bed heat, Paddy, Stored insect pests

Shading at the Booting Stage Improved the Grain Quality of Hybrid Rice Due to Reduced Spikelet Production

As a growing abiotic stress, light deficient conditions seriously affect the yield and quality of rice. However, few studies focus on the effects of shading on grain quality at the booting stage and the responses of different hybrid rice cultivars to shading. Field experiments involving four representative rice (Oryza sativa L.) cultivars across no shading (CK) and 40% shading at the booting (S) and grain filling stages (SS) were conducted in 2021 and 2022. Compared with CK, S reduced grain yield by 53.0% but increased the head rice rate by 11.4% averaged across varieties and years. The chalkiness degree (CD) and chalky grain percentage (CR) were reduced by 73.0% and 61.6% in S due to its 45.3% lower total spikelets m–2, 44.0% lower grain–leaf ratio and 23.5% lower dry weight spikelet production efficiency, compared with CK. The CD and CR in SS were 49.5% and 41.0% higher and HR was 7.1% lower than that in CK. Shading significantly reduced amylose content, peak viscosity and breakdown value, but increased protein content and setback value, and the effects of SS were greater than S. Y-liangyou900 and Liangyoupeijiu showed better milling quality, while Y-liangyou900 and Chuanyou6203 obtained a better appearance and eating quality than the other varieties under both S and SS. In conclusion, shading at the booting stage significantly improved the milling, appearance and nutritional quality, and did not reduce the cooking and eating quality, but led to a significant decline in the grain yield of hybrid rice. Moreover, Y-liangyou900 exhibited better rice quality but lower yield under shading treatments. Therefore, more attention needs to be focused on screening shade-tolerant varieties using both yield and quality to cope with climate change in the future.

Effects of Salt Stress on Grain Quality and Starch Properties of High-Quality Rice Cultivars

In recent days, there has been a noticeable surge in demand for high-quality rice. However, the influences of salinity on the quality and starch properties of high-quality rice remain unclear. Three high-quality rice cultivars (Nanjing 9108, Nanjing 5055, and Nanjing 46) were studied to investigate the responses of grain quality to salt stress. There were three treatments, including a control zero salt level (0 g·kg−1, CK), and two salt levels of 0.1 g·kg−1 (0.1% salt stress, T1) and 0.2 g·kg−1 (0.2% salt stress, T2). The study involved the assessment of the appearance, milling, cooking, and eating qualities of rice. We also conducted an analysis of pasting properties, an evaluation of starch thermal properties, and an examination of the fine structure of amylopectin. The findings suggest that as the level of salt stress increases, the yield of rice gradually declines, which is primarily due to a significant reduction in the total spikelet number and the ratio of filled grains. Compared with CK treatment, the appearance and milling quality of rice were significantly improved within the T1 treatment. In addition, the protein concentration and amylose concentration were significantly decreased, the gel consistency was significantly increased, and the cooking and eating qualities were improved. In terms of starch properties, the peak viscosity, breakdown value, infrared ratio (1022/995), and short-chain-length amylopectin ratio increased significantly, while the setback value, pasting temperature, gelatinization enthalpy, relative crystallinity, and infrared ratio (1045/1022) decreased significantly. When comparing T2 with CK, the appearance quality and cooking and eating quality had deteriorated, and the milling quality was improved. The changes in the structural and physicochemical properties of starch were opposite to those in the comparison between the T1 treatment and the CK group. Accordingly, we propose that moderate salt stress has the potential to enhance rice quality, even though there may be a slight decrease in yield. This indicates that it is feasible to cultivate high-quality rice in saline–alkali beach areas.