Cooked Rice Research Articles

Cooked germ-remained milled rice presents high stability in water-holding capacity and textural properties during frozen storage—The protection effect of oil-phase reabsorption

To enhance the stability in textural attributes of frozen cooked rice, this study has found and proposed a new strategy: retaining the rice germ in milling process. Each rice germ is comparable to a native lipid-rich microcapsule attached to the endosperm part. In the gelatinization process, leached germ oil was reabsorbed in the outer layer of rice granule. Small lipidic molecules complexed with amylose and formed type I complex, while big lipidic molecules formed separate oil phase in the matrix. This mixed construction endowed cooked germ-remained milled rice with smaller magnitude of change in the water holding capacity and the ratio of stickiness/hardness, and fewer freezable water content than white rice. This work opens an attractive field to reinforce the structural stability of cooked rice against freezing stress without exogenous additives, and benefits to screen suitable raw materials for the development of frozen rice products.

Creating of novel Wx allelic variations significantly altering Wx expression and rice eating and cooking quality

Granule-bound starch synthase I (GBSSI) encoding gene Waxy (Wx), which largely regulates the amylose content of rice grains, is a master module determining rice eating and cooking quality (ECQ). Fine-tuning amylose level of grains is an ideal strategy to improve rice quality. Through fine editing of Wxa promoter and 5′UTR by CRISPR/Cas9 system, we created 14 types of novel Wx allelic variations, of which MT7 and MT13 were able to alter Wx expression and amylose content of grains. MT7 showed fragment deletion and base insertions in CAAT-boxes, hardly detectable expression levels of GBSSI mRNA and protein, and generated 5.87% amylose in grains. MT13 had fragment deletions in the A-box and the TATA-box, low expression levels of GBSSI mRNA and protein, and generated 9.61% amylose in grains. Besides of the amylose content, MT7 and MT13 significantly reduced protein content and increased lipid content of grains compared with Wxa. A comparison of MT7, MT13 and other allelic lines demonstrated the importance of base insertion around the second CAAT-box and 31bp-deletion following the second TATA-box in modulating Wx expression. Thus, our study generated two novel Wx allelic variations which significantly alter Wx expression and amylose content of rice grains, providing not only new germplasms for soft rice breeding, but also insights into candidate cis elements of Wx.

Pulsed Electric Field for Quick-Cooking Rice: Impacts on Cooking Quality, Physicochemical Properties, and In Vitro Digestion Kinetics

Pulsed electric field (PEF) is one of the emerging technologies that has been applied in many aspects of the food industry. This study examined the impacts of a PEF on the cooking quality, physicochemical properties, nutritional factors, and in vitro protein and starch digestion of two varieties of rice, including Jasmine 105 (white non-glutinous rice) and San Pa Tong 1 (white glutinous rice). Response surface methodology (RSM) and a three-level, three-factor Box–Behnken design were employed to assess the effects of the pulse number, electric field strength, and frequency on cooking time. The findings demonstrated that the number of pulses was a crucial factor influencing cooking time. Under optimal conditions (3347–4345 pulses, electric field strengths of 6–8 kV/cm, and frequencies ranging from 6 to 15 Hz), the rice cooking time was significantly reduced by 40–50% (p < 0.05) when compared to a conventional method. Moreover, PEF-treated rice showed a significant enhancement in in vitro protein and starch digestibility (p < 0.05), as well as retained a higher content of rapidly digestible starch. These results suggested that PEF treatment is a promising green technology for producing a novel quick-cooking rice with an improved eating quality.

Genetic improvement of eating and cooking quality of rice cultivars in southern China.

The genetic improvement of rice eating and cooking quality (ECQ) is an important goal in rice breeding. It is important to understand the genetic regulation of ECQ at the genomic level for effective breeding to improve ECQ. However, the mechanisms underlying the improvement of ECQ of indica and japonica cultivars in southern China remain unclear. In this study, 290 rice cultivars (155 indica and 135 japonica cultivars) bred in southern China in the past 30 years were collected. Physicochemical indicators, namely, apparent amylose content (AAC), protein content (PC), lipid content and taste value, were measured and correlation analysis was performed. Adecrease in AAC and PC was a crucial factor for the ECQ improvement of the rice cultivars in southern China. Genome-wide association analysis and selective domestication analysis preliminarily clarified that the comprehensive utilization of major and minor genes was an important genetic basis for improvement of ECQ. An elite allele, RAmy1AA, with potential application in breeding to improve starch viscosity characteristics and ECQ, was mined. The Wxb/OsmtSSB1LT/OsDML4G/RPBFT/Du3T and Wxb/OsEro1T/Glup3G/OsNAC25G/OsBEIIbC/RAmy1AA/FLO12A gene modules, neither of which have been widely used, are proposed as the optimal allele combinations for ECQ improvement of indica and japonica cultivars in southern China. The results clarify the genetic regulation of rice ECQ improvement in southern China and provide novel genetic resources and breeding strategies for ECQ improvement in rice.

Past Forward: The Unlikely Inventor of the Automatic Rice Cooker: A Japanese Housewife's Experiments Cracked the Code of Perfectly Cooked Rice

Past Forward: The Unlikely Inventor of the Automatic Rice Cooker: A Japanese Housewife's Experiments Cracked the Code of Perfectly Cooked Rice

Past Forward: The Automatic Rice Cooker's Unlikely Inventor

Past Forward: The Automatic Rice Cooker's Unlikely Inventor

Impact of magnetic field-assisted freezing on the physicochemical properties and starch structure of cooked rice: Effects of magnetic types, intensities, and cryostasis time

A magnetic field-assisted freezing system was developed to mitigate the degradation of taste quality in frozen cooked rice (FCR). The physicochemical properties and starch structure were analyzed under varying magnetic field types, intensities, and cryostasis time. The analysis of freezing characteristics indicated that treatments with 10 mT static magnetic fields (SMF) and 6 mT alternating magnetic fields (AMF) yielded optimal results, significantly reducing the duration of the maximum ice crystal generation zone by approximately 18 min. Compared to no magnetic field (NMF) treatment, a 16-day frozen storage experiment showed significant improvements in the texture characteristics of cooked rice treated with magnetic fields. However, the moisture content of rice treated with AMF closely resembled those of freshly cooked rice, with a slight increase in yellowness compared to SMF treatment. Throughout the storage period, the crystallinity for the AMF treatment exceeded that of the SMF treatment by 2.99 %. Furthermore, compared to SMF treatment, water molecules in FCR treated with AMF are more tightly bound. Given the superior sensory scores in the AMF treatment, it can be concluded that while SMF reduces color degradation, AMF is more effective in preserving moisture, and structural density. Hence, magnetic fields, especially AMF, emerge as a promising auxiliary technology for FCR, offering a theoretical basis for advancing cold chain logistics technology for cooked rice.

Influence of Gradient Milling on Cooking and Sensory Attributes of Chinese Black Rice: Insights into Volatile Flavor Compounds.

This study investigated the impact of gradient milling on the cooking properties and sensory characteristics of Yangxian black rice. The results showed that as the degree of milling increased, the gelatinization time decreased (36.85-23.54 min) and the water uptake ratio of whole black rice (188.29%) was significantly lower compared to that of refined grains (194.05%). Low-field nuclear magnetic resonance (NMR) was further used to monitor the water concentration and distribution of black rice during soaking and cooking. It was found that the bran layers of black rice, as a physical barrier, impeded the water penetration into the kernels for a given soaking and cooking duration. The sensory evaluation conducted by a panel of trained volunteers demonstrated a high score for all sensory attributes in slightly milled black rice, corroborating findings from the taste analyzer. Through correlation analysis of volatile components determined by gas chromatography-mass spectrometry (GC-MS), smell scores in sensory evaluation, and electronic nose response values, 2-pentyl-furan (54.84-12.72 ng/g) and guaiacol (19.39-5.51 ng/g) were found to be the predominant volatile flavor contributors in cooked black rice. Overall, this study provides valuable insight into the intricate relationship between milling degrees and the cooking properties, sensory characteristics, and volatile flavor compounds of Yangxian black rice.

Evaluation of thiamine and riboflavin in different varieties of rice grown in Kurigram district, Bangladesh

ContextRice is indeed a staple food in many parts of the world, including Bangladesh. This research aimed to evaluate the two essential vitamin levels in different processed rice sunned, parboiled, cooked sunned, cooked parboiled, and washed cooked rice. ObjectiveThe study focused on analyzing the thiamine (vitamin B1) and riboflavin (vitamin B2) contents in 10 different varieties of paddy samples grown in the Kurigram district of Bangladesh. MethodsA high performance liquid chromatographic (HPLC) technique assembled with fluorescence detector was employed for these analyses. Two calibration curves were generated to analyze vitamin B1 and B2 (for thiamine the regression coefficient, r2 = 0.9992 and riboflavin r2 = 0.9989). The study demonstrated a recovery rate of 96.88 % for vitamin B1 and 104.24 % for vitamin B2. Overall, these findings provide valuable insights into the vitamin B1 and B2 contents across different rice samples. Results and conclusionThe results showed that the parboiled samples had the highest thiamine content, ranging from 342.50 ± 0.3 to 673.0 ± 7.5 μg/100 g, compared to the sunned samples, which had a range of 209.5 ± 0.3 to 337.4 ± 4.3 μg/100 g. Conversely, the sunned samples had the highest riboflavin content, ranging from 26.4 ± 0.2 to 59.6 ± 0.3 μg/100 g, while the parboiled samples had a range of 3.0 ± 0.1 to 26.6 ± 0.01 μg/100 g. Additionally, it was observed that the steaming process increased the thiamine content and reduced the riboflavin content in parboiled rice samples but decreased both the thiamine and riboflavin in sunned rice samples. Another study showed a gradual decrease in the levels of both vitamins B1 and B2 in sunned, cooked sunned and washed cooked sunned rice samples. SignificanceThese findings provide valuable insights into the impact of processing methods, such as parboiling and steaming, on the thiamine and riboflavin contents in rice. The results suggest that parboiled rice may be a preferable choice for individuals seeking higher thiamine content in their diet, while sunned rice may contain higher levels of riboflavin. The results shed light on the nutritional profiles of different rice varieties and highlight the potential impact of processing techniques on the vitamin content of rice.

Effect of nitrogen and phosphorus application on starch characteristics and quality of rice with different nitrogen efficiency.

The application of nitrogen and phosphorus fertilizers is an important factors affecting the quality of rice, and different nitrogen-efficient rice varieties show significant differences in their response to nitrogen and phosphorus application. In this experiment, a low-nitrogen-high efficiency variety (Deyou 4727) and a high-nitrogen-high efficiency variety (Jingyou 781) were selected, and the changes in rice quality and differences in starch structure under nitrogen-phosphorus interaction treatments were determined. Appearance, flavor, starch content and thermodynamic properties, endosperm cell arrangement, and starch granule morphology and size were significantly influenced by variety, nitrogen-phosphorus interactions, and their interaction effects. The effect of nitrogen fertilizer on quality was greater than that of phosphorus fertilizer. The whiteness and chalkiness rates of Deyou 4727 first decreased and then increased with increasing nitrogen fertilizer application, wheras the appearance quality of Jingyou 781 increased with increasing nitrogen fertilizer application. Starch crystallinity in Deyou 4727 first increased and then decreased with increasing nitrogen fertilizer application, whereas starch crystallinity in Jingyou 781 increased continuously with increasing nitrogen fertilizer application. The application of phosphorus fertilizer led to an increase in starch crystallinity in both nitrogen-efficient rice varieties, consistent with the response of different rice varieties to nitrogen and phosphorus in terms of appearance and chalkiness. With the increasing application of nitrogen and phosphorus fertilizers, the differences in the physicochemical properties and structure of starch became more significant. High-nitrogen-efficient rice varieties can significantly improve appearance quality under high nitrogen conditions, and the interactions of medium-high nitrogen and low-medium phosphorus can lead to a significant decrease in starch thermal parameters and retention rate, thus improving rice cooking quality. Low-nitrogen-efficient rice varieties can also improve the quality of rice under low-medium-nitrogen conditions with appropriate application of phosphorus fertilizer.

Effect of adding various supplements on physicochemical properties and starch digestibility of cooked rice

This study investigated the physicochemical modifications of cooked rice caused by adding various supplements (rapeseed oil, dried wasabi powder, and dried chili pepper powder). The physicochemical and digestive properties of treated cooked rice were analyzed using multiple techniques to determine the impact of supplements on the rice quality, including its starch digestibility. All samples with added supplements showed an increase in surface firmness (0.77–0.95 kg·m/s2 (N)) and a decrease in thickness (2.23–2.35 mm) and surface adhesiveness (1.43–7.22 J/m3). Compared to the control group, two absorption peaks at 2856 and 1748 cm−1 and new signals at 1683 and 1435 cm−1 appeared in the Fourier transform infrared (FTIR) spectroscopy. Analysis of FTIR results revealed that the interaction force was mainly through noncovalent interactions. Moreover, adding supplements increased the resistant starch (RS) levels in all samples. Scanning electron microscopy (SEM) suggested that oil-enriched phases, proteins, and polyphenols could cause large agglomeration and loose gel structure. These results suggested the formation of amylose-guest molecule complexes, which may influence starch functionality. Our work could provide insight into the starch–supplement interactions and the key factors affecting starch digestibility.

Resiliency evaluation of sheltering in a net-zero energy house during summer power outage

This study examines the growing issue of power outages caused by natural disasters and proposes the use of net-zero energy houses (ZEH) as a safe alternative to traditional shelters. A ZEH, equipped with an independent energy system, can maintain essential living standards such as thermal comfort and 24-hour air conditioning during a summer power outage, reducing the risk of heatstroke. The research tested a ZEH in Japan, confirming its ability to support critical household appliances like refrigerators, lighting, and water heaters for up to 72 h. This demonstrates the ZEH's potential for offering safe, comfortable shelter during emergencies while addressing problems like poor sanitation and lack of privacy found in typical shelters. The experimental ZEH is located in Shizuoka, Japan, is a steel structure, and has a floor area of 110.94 m2 and overall heat transmission coefficient (UA) of 0.48 W/m2·K. The ZEH was equipped with a 5.1 kW photovoltaic system and 5.6/11.2 kWh storage battery (BT), which produced an output of up to 2.0/4.0 kVA. A ZEH with a 5.6 kWh BT can provide for ventilation and living/dining room/kitchen air conditioning (AC), refrigerator, television, lighting, mobile phone charging, rice cooker, microwave, electric kettle, and heat pump water heater during a 72-h power outage. The ZEH with a 11.2 kWh BT can also provide bedroom AC and high-load home appliances for lunch and dinner, in addition to a 5.6 kWh BT. The use of AC in a self-supporting circuit maintained the thermal environment at a low heat stroke risk.

Dynamic changes in aroma compounds and precursor substances during rice cooking

Cooking is a key process in forming cooked rice flavor, and more data on aroma compounds should be needed during rice cooking. This paper tracked dynamic changes in aroma compounds, sugars, amino acids, and fatty acids during cooking. After soaking, the content of glucose, fructose, oleic acid, and linoleic acid increased. In the hydrothermal cooking stage, glucose, aspartic acid, glutamic acid, and alanine increased significantly (p < 0.05), while fructose, oleic acid, and linoleic acid first increased and then decreased. In raw rice and soaked rice, alkanes and alkenes were the main volatile compounds, and the content of hydrocarbon compounds decreased in the hydrothermal cooking stage, and many aldehydes, alcohols, ketones, and furan compounds were generated. A total of 28 aroma compounds were sniffed by GC-O-MS, and 13 aroma compounds with OAV >1 were screened out. These results showed that raw rice and soaked rice had similar aroma characteristics and aroma precursor substances that mainly accumulated in the SO10 or ST10 stage, and hydrothermal cooking was the key process of rice aroma formation.

Empowering energy conservation: A prototype of household energy consumption monitoring based on Internet of Things

Abstract One of the obstacles to control household energy consumption is unavailability electricity instruments/tools to monitor electricity energy consumed by appliances causing a lack of awareness of household energy saving. Energy meter installed on buildings only show electricity consumption in total. This study aims to design and create a prototype system that can monitor and control the electrical appliances usage utilizing the Internet of Things (IoT)-based electronic devices where electricity usage data is stored in Firebase real-time database. The methods carried out are arranged in several stages, starting from data collection, design, configuration, and implementation. The tools used in this research will utilize the ESP8266 as the microcontroller, the PZEM-004T as current sensor and the Blynk as the web server. The tool will send current voltage (Volt (V)) and capacity (Watt (W)) data and then converted to energy and also the costs incurred from electricity usage based on the basic electricity tariff of National Electricity Company (PLN) and the results can be seen directly through IoT (i.e. smartphone, PC, laptop). The accuracy of power measurement by the system is 97.4% compared to measurement used by watt-checker. The results of this study show that an electrical power monitoring system makes people easier to monitor electrical power consumption by appliances used. The pilot measurement shows that a unit system can monitor electricity usage for four units of electronic equipment i.e. water pump, Television, fridge, electrical iron, rice cooker, etc. precisely and succeeded to control and increase energy saving awareness to reduce electricity consumption at the end.

Karakteristik Fisik Beras Analog dari Jagung Berkadar Amilosa Sedang dengan Menggunakan Ulir Ekstruder Kecepatan Menengah

Indonesia has the highest rice consumption rate in the world, averaging 130 kg per capita per year. Despite government efforts to reduce this through food diversification programs, there has been little success. One approach to reducing rice consumption is to process non-rice ingredients into rice analogues that have similar characteristics to traditional rice. The amylose content of the ingredients plays a significant role in determining the physical properties of these rice analogues. Additionally, the screw speed of the extruder used in the production process also influences these physical characteristics. This study aimed to explore the impact of extruder screw speed and material amylose content on the physical properties of rice analogues. Local corn flour was mixed with high-amylose corn starch to create mixtures with amylose contents of 16.99, 19.35, 21.72% and 24.08%. The tested screw speeds were 100, 125, and 150 rpm. The evaluated physical characteristics included the hardness of the rice analogues, bulk density, cooked rice hardness, gumminess, and sensory properties of the cooked rice. The results showed that as amylose levels increased, the hardness of the rice analogues, cooked rice hardness, and gumminess also increased. Similarly, increasing the screw speed of the extruder led to higher cooked rice hardness, gumminess, and rice analogue hardness, but it decreased bulk density. The optimal extruder operating conditions were found to be an amylose content of 21.72% and a screw speed of 100 rpm, producing rice analogues with a hardness of 3610 gf, a bulk density of 0.63 g/mL, a cooked rice hardness of 3200 gf, and gumminess of 1200 gf.

Health Hazards Associated with Dietary Exposure of Female Rat to Cadmium-Contaminated Cooked Rice: Biochemical, Hormonal, and Histopathological Analysis.

The actual exposure, bioavailability, and body burden of dietary cadmium (Cd) vary with the food matrix. Here, we evaluated the health hazards of 45-day long-term exposure of growing Sprague-Dawley (SD) female rats to a natural and endogenous Cd-contaminated brown and white cooked rice dietary model. Cd was found mainly in the duodenum, kidney, and liver; the cecum and colon also contained substantial amounts of Cd in rats fed Cd-contaminated cooked white rice (cWR-test) but not Cd-contaminated cooked brown rice (cBR-test). Damage due to Cd exposure was reflected in liver dysfunction, altered estradiol levels, and distinctive pathologies in organ systems, although urinary Cd (U-Cd) excretion and blood Cd (B-Cd) were not detectable, suggesting that these are not the most accurate or appropriate biomarkers for evaluating dietary Cd exposure. Brown rice, despite being higher in Cd, can reduce Cd absorption and distribution in organs and increase the volume of Cd-containing feces, even achieving slightly higher excretion and lower apparent absorption rates of Cd than white rice, thereby reducing Cd damage to the body. The beneficial components of brown rice such as more dietary fiber, rice bran oil and polyphenol were speculated therefore to confer a degree of protection or repair. Nevertheless, the high apparent absorption levels observed here (> 5%) and signs of significant physical damage indicate that more stringent Cd intake guidelines and measures are needed to minimize Cd levels in rice.

Improving the medium composition for the production of the natural blue-violet pigment violacein by a new Janthinobacterium sp. isolate.

The interest in natural compounds has increased primarily due to their beneficial health and environmental aspects. However, natural sources of some compounds, such as bluish pigments, are limited, requiring the development of efficient processes to meet commercial demands. This study isolated a blue-violet bacterium from spoiled cooked rice and identified it as a potential new species of Janthinobacterium through 16S rDNA analysis. Ultra-high performance liquid chromatography-tandem mass spectrometry analyses confirmed that the blue-violet pigment violacein was responsible for the bluish color. In laboratory conditions, different carbon and nitrogen sources were evaluated in submerged culture media to enhance pigment production. Glycerol did not result in significant pigment production by this strain, as expected from previous reports. Instead, a culture medium composed of yeast extract and fructose yielded higher pigment production, reaching about 113.68±16.68 mg l-1 after 120 h. This result provides crucial insights for future studies aiming for sustainable and commercially viable violacein production. Based on a bioeconomy concept, this approach has the potential to supply natural and economic bluish pigments for various industrial sectors, including pharmaceutical, cosmetic, and food.

Microbiome profile and nutritional benefits of traditional overnight soaked cooked rice

This study explores the microbial composition, nutrient content, and health benefits of "Panta Bhat," a traditional dish made from cooked rice soaked overnight, commonly consumed in Southeast Asia, particularly in Bangladesh and India. The research aims to evaluate its potential as an affordable food to enhance nutrition and combat malnutrition in population where rice is a staple. The findings reveal that soaking cooked rice overnight initiates mild fermentation, leading to the consistent growth of beneficial bacteria from the Bacillota phylum. 16S rRNA sequencing identified two Gram-positive bacteria, Leuconostoc lactis and Weissella confusa, known for their probiotic and lactic acid-producing capabilities. Furthermore, mineral analysis via ICP-MS showed significant increases in free iron, zinc, manganese, boron, calcium, magnesium, and potassium in soaked rice compared to unsoaked rice. Notably, there was a significant reduction in glycaemic response after consuming soaked rice (P < 0.01). This study suggests that overnight-soaked cooked rice is a promising source of probiotics and enhanced micronutrients, making it a valuable and cost-effective, low-glycaemic food option.

Antimicrobial Activities and Probiotic Properties of Bacillus sp. Strains Isolated from Fermented Cooked Rice

Antimicrobial Activities and Probiotic Properties of <i>Bacillus</i> sp. Strains Isolated from Fermented Cooked Rice

Lysine 98 in NAC20/NAC26 transcription factors: a key regulator of starch and protein synthesis in rice endosperm

Starch and proteins are main storage product to determine the appearance, cooking, texture, and nutritional quality of rice (Oryza sativa L.). OsNAC20 and OsNAC26, as pivotal transcription factors, redundantly regulate the expression of genes responsible for starch and protein synthesis in the rice endosperm. Any knockout of OsNAC20 or OsNAC26 did not result in visible endosperm defects. In this study, we had isolated and characterized a mutant named as floury endosperm25 (flo25). The caryopsis of the flo25 mutant exhibits a floury endosperm, accompanied by reductions in both the 1000-grain weight and grain length, as well as diminished levels of total starch and protein. Through map-based cloning, it was determined that FLO25 encodes a NAM, ATAF, and CUC (NAC) transcription factors, namely OsNAC26, with a lysine to asparagine substitution at position 98 in the flo25 mutant. Remarkably, lysine 98 is conserved across plants species, and this mutation does not alter the subcellular localization of OsNAC26 but significantly attenuates its transcriptional activity and its ability to activate downstream target genes. Furthermore, the mutant protein encoded by OsNAC26-flo25 could interact with OsNAC20, disrupting the native interaction between OsNAC20 proteins. Additionally, when lysine 98 is substituted with asparagine in OsNAC20, the resulting mutant protein, OsNAC20(K98N), similarly disrupts the interaction between OsNAC26 proteins. Collectively, these findings underscore the pivotal role of Lysine 98 (K) in modulating the transcriptional activity of NAC20/NAC26 within the rice endosperm.