Rice Color Research Articles

Differential Study on Estimation Models for Indica Rice Leaf SPAD Value and Nitrogen Concentration Based on Hyperspectral Monitoring

Soil and plant analyzer development (SPAD) value and leaf nitrogen concentration (LNC) based on dry weight are important indicators affecting rice yield and quality. However, there are few reports on the use of machine learning algorithms based on hyperspectral monitoring to synchronously predict SPAD value and LNC of indica rice. Meixiangzhan No. 2, a high-quality indica rice, was grown at different nitrogen rates. A hyperspectral device with an integrated handheld leaf clip-on leaf spectrometer and an internal quartz-halogen light source was conducted to monitor the spectral reflectance of leaves at different growth stages. Linear regression (LR), random forest (RF), support vector regression (SVR), and gradient boosting regression tree (GBRT) were employed to construct models. Results indicated that the sensitive bands for SPAD value and LNC were displayed to be at 350–730 nm and 486–727 nm, respectively. Normalized difference spectral indices NDSI (R497, R654) and NDSI (R729, R730) had the strongest correlation with leaf SPAD value (R = 0.97) and LNC (R = −0.90). Models constructed via RF and GBRT were markedly superior to those built via LR and SVR. For prediction of leaf SPAD value and LNC, the model constructed with the RF algorithm based on whole growth periods of spectral reflectance performed the best, with R2 values of 0.99 and 0.98 and NRMSE values of 2.99% and 4.61%. The R2 values of 0.98 and 0.83 and the NRMSE values of 4.88% and 12.16% for the validation of leaf SPAD value and LNC were obtained, respectively. Results indicate that there are significant spectral differences associated with SPAD value and LNC. The model built with RF had the highest accuracy and stability. Findings can provide a scientific basis for non-destructive real-time monitoring of leaf color and precise fertilization management of indica rice.

Zinc Biofortification of Selective Colored Rice Cultivars: Improvement of Zinc Uptake, Agronomic Traits, and Nutritional Value

It is difficult for ordinary rice to break the zinc-rich standard. However, employing multiple unique rice cultivar resources through biofortification of agronomic measures to achieve the target is a promising attempt. In this study, a pot experiment was conducted on seven different colored rice cultivars (GFHN 166, GFHN 168, GFHN 169, GH 1, GXHZ, GHSZ, and YXN), aiming to analyze the effect on zinc content, growth, quality, and health risk index when spraying zinc (400 g/ha) on the leaves at the heading age. The result indicated that after foliar biofortification treatment, the zinc content and the zinc accumulation of colored rice grains could reach up to 41.55 mg/kg and 2.28 mg/pot, respectively, increased by 43.92% and 65.22%. In addition, the SPAD value and grain protein content was 42.85 and 8.49%, also increased significantly by 2.15% and 2.91%, respectively. Among these, GXHZ and GHSZ could realize the zinc content of polished rice up to 69.7 mg/kg and 55.4 mg/kg, breaking through the standard of zinc-enrich rice (45 mg/kg). GXHZ plant height increased by 11.22%, and the zinc harvest index (6.44%) and zinc use efficiency (26.79%) were the highest. Meanwhile, the biofortification promoted the SPAD value of GHSZ and the protein content of GFHN 166 by 4.95% and 24.81%, respectively. Foliar-applied zinc at the heading stage is a vital practice to get better agronomic indicators, quality, and grain zinc biofortification of colored rice.

Solid-state cultivation of multiple industrial strains of koji mold on different Thai unpolished rice cultivars: biotransformation of phenolic compounds and their effects on antioxidant activity.

Colored rice is abundant in polyphenols, and koji molds have potential for biotransformation. This study aimed to produce Thai-colored rice koji to study its polyphenolic biotransformation. Four industrial koji mold strains: Aspergillus oryzae 6001, A. oryzae 6020, A. sojae 7009, and A. luchuensis 8035, were cultivated on unpolished Thai-colored rice (Riceberry and Sangyod), unpolished Thai white rice (RD43), and polished Japanese white rice (Koshihikari). We discovered that koji molds grew on all the rice varieties. Methanol extracts of all rice kojis exhibited an approximately 2-fold or greater increase in total phenolic content and DPPH antioxidant activity compared to those of steamed rice. Moreover, quercetin, quercetin-3-O-glucoside, isorhamnetin-3-O-glucoside, ferulic acid, caffeic acid, protocatechuic acid, vanillic acid, (+)-catechin, and (-)-epicatechin content increased in Riceberry and Sangyod koji samples. Consequently, Aspergillus solid-state cultivation on unpolished Thai-colored rice exhibited higher functionalization than the cultivation of unpolished Thai white rice and polished Japanese white rice.

The mechanism exploration of different colored rice for immunomodulation based on UPLC-Q-TOF, network pharmacology, and cell experiments

Rice has a long history as a staple food consumed by half of the world’s population. Compared with white rice (WR), colored rice (CR) has more nutritional value because it contains rich active ingredients. In this study, the potential mechanism of CR (red rice (RR), green rice (GR), black rice (BR), and purple rice (PR)) for immunomodulation was explored by UPLC-Q-TOF, network pharmacology, and cell experiment. kuromanin, kaempferol-3-O-arabinoside, keracyanin, guajavarin, and hispidulin in CR were the critical components for improving immunity. These ingredients are mainly found in BR. Cell experiments supported that kuromanin plays a role in maintaining immune homeostasis. In the normal environment, it promotes cell proliferation and improves DNA repair; In an inflammatory environment, it binds to AKT1 and reduces the release of inflammatory factors through the MAPK and NFKB signaling pathways. The study provides a guideline for humans to utilize the precise nutrition of CR.

Comparative Metabolic Profiling of Different Colored Rice Grains Reveals the Distribution of Major Active Compounds and Key Secondary Metabolites in Green Rice.

Pigmented rice grains are important resources for health and nutritional perspectives. Thus, a thorough dissection of the variation of nutrients and bioactive metabolites in different colored rice is of global interest. This study applied LC-MS-based widely targeted metabolite profiling and unraveled the variability of metabolites and nutraceuticals in long grain/non-glutinous black (BR), red (RR), green (GR), and white rice (WR) grains. We identified and classified 1292 metabolites, including five flavonoid compounds specific to BR. The metabolite profiles of the four rice grains showed significant variation, with 275-543 differentially accumulated metabolites identified. Flavonoid (flavone, flavonol, and anthocyanin) and cofactor biosynthesis were the most differentially regulated pathways among the four rice types. Most bioactive flavonoids, anthocyanidins (glycosylated cyanidins and peonidins), phenolic acids, and lignans had the highest relative content in BR, followed by RR. Most alkaloids, amino acids and derivatives, lipids, and vitamins (B6, B3, B1, nicotinamide, and isonicotinic acid) had higher relative contents in GR than others. Procyanidins (B1, B2, and B3) had the highest relative content in RR. In addition, we identified 25 potential discriminatory biomarkers, including fagomine, which could be used to authenticate GR. Our results show that BR and RR are important materials for medicinal use, while GR is an excellent source of nutrients (amino acids and vitamins) and bioactive alkaloids. Moreover, they provide data resources for the science-based use of different colored rice varieties in diverse industries.

Analysis of arsenic in rice and domestic water supply in Baguio City, Philippines

Numerous studies have found that rice and water, as components of the human diet, are potential pathways of arsenic exposure in humans. Due to the negative health effects linked with arsenic exposure, the quality of drinking water and rice samples must be continually monitored. This research was carried out in Baguio City, a small urban center in the Philippines. Following microwave digestion, arsenic in rice and water samples were determined using Atomic Absorption Spectrometry. The results showed that the National Food Authority (NFA) rice samples had arsenic content below the detection limit, indicating that this commercially available rice does not pose any health risk to Filipino consumers in terms of arsenic exposure. The arsenic value in other rice samples ranged from 8 μg/L to 27 μg/L, with the lowest and highest values found in organic brown rice and white rice varieties, respectively. Despite detectable arsenic in all 20 rice samples, all values were less than the maximum contaminant level (MCL) of 150 μg/L. Despite higher arsenic content in mixed rice than in white and organic colored rice, the mean differences are not significant, as proven by the Kruskal Wallis Test. All drinking water samples bought from water refilling stations had no detectable arsenic, while eight of the 18 (44%) of the spring water samples showed detectable amounts but are far below MCL of arsenic in drinking water. The findings suggest that the amount of arsenic in rice and spring water samples are too low to pose health risks over a short period of time.

Inventory Of Beras rendang Recipes As Traditional Food In Fifty City District, West Sumatera

Differences in selecting ingredients, measuring ingredients and techniques for making rendang rice mean that the quality produced is also different. The basic technique for making rendang rice is that the sticky rice is mashed, then the coconut milk, granulated sugar and vanilla are cooked until it thickens until it becomes candied. This research aims to describe the standardization of recipes, methods of making and the quality of rendang rice in Nagari Padang Japang, LimaPuluh City Regency. This type of research is qualitative and quantitative research using mixed methods. The data in this research uses primary data. Qualitative data collection techniques are observation, interviews, documentation and quantitative data collection techniques are organoleptic test questionnaire format. Qualitative data analysis techniques use three activity streams, namely: data reduction, data presentation, drawing conclusions and quantitative data analysis techniques using the formula (Mx=∑ x / N), data validity, testing the validity of qualitative data, namely: extended participation, diligent observation, and triangulation. Based on the research results, 3 rendang rice recipes were obtained. The results of the organoleptic test obtained the highest score by Mrs. Misna from Jorong Ampang Gadang with an average score of 19.6. Standardization of rendang rice recipes is carried out by organoleptic tests to obtain good quality rendang rice including: shape of rendang rice (neat and uniform), color of rendang rice (white), aroma of rendang rice (fragrant), texture of rendang rice (soft) and taste of rendang rice ( sweet).

Character Association Studies for Yield, Nutritional and Cooking Quality Characters in Coloured Rice (Oryza sativa L.)

In the present study 35 coloured rice genotypes along with three checks were evaluated in Randomized Complete Block Design for yield, nutritional and cooking quality traits to study association between the yield, nutritional and cooking quality traits. Correlation studies showed positive and significant correlation of grain yield per plant with yield contributing characters like ear bearing tillers per plant, panicle length, test weight, number of filled grains per panicle and some nutritional characters like protein content and anthocyanin content. The path analysis revealed that traits like ear bearing tillers per panicle, test weight, number of filled grains per panicle, alkali spreading value and anthocyanin content showed not only positive direct effect but also positive correlation with grain yield suggesting the importance of direct selection for above characters. The residual effect in the present study was 0.3696 and 0.2348 at phenotypic and genotypic levels respectively, indicating that the characters included in the present study clearly explained the direct and indirect effects on the dependent variable to some extent.

Antioxidant and Anthocyanin-Rich Vinegar Fermented from Thai Colored Rice Varieties

This study aims to produce antioxidant and anthocyanin-rich vinegar using three types of Thai rice through surface culture fermentation (SCF). Three varieties of Thai rice with different colors, including Khao Dawk Mali 105 (white color), Sangyod (brown color) and Hom Nil (black color), were used as a substrate for vinegar fermentation. The different Thai rice varieties were hydrolyzed by boiling and enzymatic hydrolysis. The sweetness of the hydrolyzates was adjusted by adding granulated sugar at 20 °Brix and using it as a substrate. A mixed culture of Saccharomyces cerevisiae var. burgundy and S. cerevisiae var. kyokai was used as a yeast starter for alcohol fermentation. After 4 weeks of fermentation, Acetobacter aceti TISTR 354 required only 10 days to convert alcohol into acetic acid by the surface-culture fermentation method. Vinegar produced from the Thai rice varieties contained acetic acid at a concentration of more than 4.0 % (v/v), with residual alcohol concentrations less than 0.5 % (v/v). Hom Nil vinegar presented an anthocyanin content of 2.39 ± 0.44 mg/L and had the highest antioxidant activity, with 428.47 ± 4.04 g/mL (Total phenolic content; TPC), 71.80 ± 0.00 g/mL (Ferric reducing antioxidant power assay; FRAP), and 49.27 ± 0.27 % inactivation (2,2-Diphenyl-1-picrylhydrazyl; DPPH). A sensory panel rated the vinegar fermented from the three varieties as ‘like slightly’ on a 9-point hedonic scale. HIGHLIGHTS Three distinct Thai rice varieties, each with unique colors (white, brown, and black), were utilized as substrates for vinegar fermentation Hydrolysis of the rice substrates involved boiling and enzymatic processes, with sweetness adjusted using granulated sugar at 20 °Brix A mixed culture of cerevisiae var. burgundy and S. cerevisiae var. kyokai served as a yeast starter for alcohol fermentation The innovative surface-culture fermentation method employed Acetobacter aceti TISTR 354, converting alcohol into acetic acid in just 10 days Hom Nil rice vinegar exhibited remarkable attributes, with an anthocyanin content of 2.39 ± 0.44 mg/L and exceptional antioxidant activity (428.47 ± 4.04 g/mL TPC, 71.80 ± 0.00 g/mL FRAP and 49.27 ± 0.27 % DPPH inactivation) Sensory evaluation by a panel yielded a ‘like slightly’ rating on a 9-point hedonic scale for vinegars derived from all 3 rice varieties GRAPHICAL ABSTRACT

Morphology Characteristics of Local Rice (Oryza Sativa L.) Rice Lands of Long Tebulo Village, North Kalimantan

Local rice (Oriza sativa L). is an annual plant cultivated by local people once a year. Local rice in the Malinau Regency area has different names for rice cultivars based on the local community's ethnicity or the person who brought the seeds. The aim of this research is to find out the local rice cultivars in the rice fields in Long Tebulo village and to find out the characteristics of the local rice fields in Long Tebulo village. This research was carried out from November 2020 to February 2021. The methods used in the research were qualitative analysis, exploration and characterization. The research results are available. There are 10 types of local rice cultivars, there are 6 sticky rice cultivars including Adan Saleng, Adan Bala, Adan Pute, Uro, Pulut Embeng, Pulut Bu'ung, and 4 ordinary rice cultivars, namely Bere, Bawang, and Gula/bread, based on plant characteristics. Rice has different ages. plant height, panicle length, grain shape, age, and rice color.

MINI REVIEW: BLACK RICE (Oryza sativa L. Indica) AS POTENTIAL FOOD FOR ANTIHYPERGLYCAEMIC

In Indonesia, rice (Oryza sativa L.) has different colors and shapes, visible from the plants and rice. There are several types of rice, one of which is black rice (Oryza sativa L. indica). Researchers are motivated to explore the benefits of black rice in Indonesia. This interest stems from the potential health benefits of black rice, such as its benefits in treating diabetes mellitus. The effectiveness of reducing blood sugar levels is crucial in the context of the increasing prevalence of diabetes in Indonesia, as projected by the International Diabetes Federation for 2045. The author made observations on the phytochemical and pharmacological activities of black rice, aiming to lay the foundation for further study and development. By searching online journals in the Scopus and PubMed databases using the keywords (“Black Rice”) AND (antidiabetic) OR (diabetes) OR (“glucose lowering”) for the last 10 years, the filtering process produced 3 articles on Scopus and 5 articles on PubMed, providing accurate data for review. Results show that black rice contains bioactive compounds such as flavonoids, phytic acid, polyphenolic compounds, and oryzanol, which provide significant health benefits. Anthocyanins, the main compounds responsible for the color of rice, contribute to antihyperglycemic properties and have various pharmacological activities, one of which is anti-diabetic benefits. In addition, the high content of anthocyanins, fiber, and other nutrients in black rice makes it effective in managing the glycemic index, and blood glucose levels, and improving overall health ...

Effect of Degree of Milling on Proximate and Mineral Composition, Physicochemical, Colour Characteristics and Pasting Properties of Broken Brown Rice Fraction from a Selected Variety (FARO 64)

The effect of degree of milling (DOMs) between 0 and 12% on proximate and mineral composition, physicochemical, colour, and pasting properties of broken brown rice from the FARO 64 rice variety were evaluated. Each milling level reduced the ash, protein, fat, and fibre content. Ash and fibre were removed most at 9% DOM. Maximum fat loss was observed at 3% DOM. The levels of Ca, Na, Mg, and K were not significantly different (p< 0.05) at 9 and 12 DOM. The starch and the amylose contents increased from 0 to 12% DOM. The least values were at 0 DOM for L* and h, while the highest were at 12 DOM for a*, b*, and c. WAC and WBC increased as the DOM increased from 0 to 12%. Pasting properties differed significantly (P<0.05) for BDV at 0-12% DOM, while PV, TV, FV, and SBV differed significantly (P<0.05) at 0-6% DOM.

Metabolomics Reveals Antioxidant Metabolites in Colored Rice Grains.

Colored rice is richer in nutrients and contains more nutrients and bioactive substances than ordinary white rice. Moderate consumption of black (purple) rice has a variety of physiological effects, such as antioxidant effects, blood lipid regulation, and blood sugar control. Therefore, we utilized nontargeted metabolomics, quantitative assays for flavonoid and phenolic compounds, and physiological and biochemical data to explore the correlations between metabolites and the development of antioxidant characteristics in pigmented rice seeds. The findings indicated that, among Yangjinnuo 818 (YJN818), Hongnuo (HN), Yangchannuo 1 hao (YCN1H), and Yangzi 6 hao (YZ6H), YZ6H exhibited the highest PAL activity, which was 2.13, 3.08, and 3.25 times greater than those of YJN818, HN, and YCN1H, respectively. YZ6H likewise exhibited the highest flavonoid content, which was 3.8, 7.06, and 35.54 times greater than those of YJN818, HN, and YCN1H, respectively. YZ6H also had the highest total antioxidant capacity, which was 2.42, 3.76, and 3.77 times greater than those of YJN818, HN, and YCN1H, respectively. Thus, purple rice grains have stronger antioxidant properties than other colored rice grains. Receiver operating characteristic (ROC) curve analysis revealed that trans-3,3',4',5,5',7-hexahydroxyflavanone, phorizin, and trilobatin in the YZ6H, HN, and YCN1H comparison groups all had area under the curve (AUC) values of 1. Phlorizin, trans-3,3',4',5,5',7-hexahydroxyflavanone, and trilobatin were recognized as indices of antioxidant capability in colored rice in this research. This research adds to the understanding of antioxidant compounds in pigmented rice, which can increase the nutritional value of rice and promote the overall well-being of individuals. This type of information is of immense importance in maintaining a balanced and healthy diet.

Seed Nutrient and Seed Hormonal Contents Underlying Anaerobic Germination Tolerance in Black Coloured Rice Landraces of Tamil Nadu

Seed Nutrient and Seed Hormonal Contents Underlying Anaerobic Germination Tolerance in Black Coloured Rice Landraces of Tamil Nadu

Development of Anthocyanin-Rich Gel Beads from Colored Rice for Encapsulation and In Vitro Gastrointestinal Digestion.

Colored rice anthocyanins are water-soluble natural pigments that can be used as an active ingredient in healthy food and pharmaceutical products. However, anthocyanin utilization is limited because of its instability. This work produced anthocyanin-rich gel beads from colored rice using a modified ionotropic gelation technique for encapsulation, and their efficacy was studied in vitro in the gastrointestinal tract. In total, 15 colored rice samples of three types (whole grain rice, ground rice, and ground germinated rice) were screened to identify the highest anthocyanin content. The anthocyanin content of the whole grain rice was significantly (p < 0.05) higher than it was in the ground and ground germinated rice. The sample with the highest anthocyanin content (1062.7 µg/g) was the black glutinous rice grain from Phrae, chosen based on its anthocyanin-rich crude extract. A new formula using a modified ionotropic gelation technique was prepared for the inclusion of the extract in gel beads. The results indicated that the incorporation of oil and wax significantly increased the encapsulation efficiency of the gel beads (% EE value of 85.43%) and improved the bioavailability of the active ingredient. Moreover, after simulated digestion, the release of anthocyanin and total phenolic content occurred more than five times. Scanning electron microscopy revealed that the surface of the gel beads was smooth. Furthermore, the presence of polyphenols and polysaccharides in the gel beads was confirmed using FTIR. The oil-wax-incorporated, anthocyanin-rich gel beads could be implemented for antioxidant delivery into the gastrointestinal tract to further improve healthy food and nutraceutical products.

CLASSIFICATION OF RICE QUALITY LEVELS BASED ON COLOR AND SHAPE FEATURES USING ARTIFICIAL NEURAL NETWORK BASED ON DIGITAL IMAGE PROCESSING

Rice is the staple food of most Indonesians. In identifying the quality of rice, it can be seen from physical characteristics such as the color and shape of rice, because these characteristics can make an object can be identified properly and clearly. In general, what is done in determining the quality of rice by looking at its color and shape. But usually the human eye in identifying objects is sometimes less accurate which is influenced by several factors, such as age. So, several studies were conducted that tried to solve the problem by using digital image processing. However, the accuracy results obtained are still not accurate, because the datasets used in the previous study were relatively small, namely around 80 images, although the average level of accuracy obtained was quite high, but the number of datasets used was very small so that the level of accuracy was still inaccurate. Therefore, in this study, it is proposed that the title of classification of rice quality levels using JST based on digital image processing which divides rice into 3 classifications, namely, good, good enough, and not good where in this study using 330 digital images to produce a more accurate level of accuracy. In this study, there are several stages, namely, image retrieval, preprocessing, segmentation, morphological, feature extraction, and classification using artificial neural networks. Based on the research conducted, training accuracy was produced with an average accuracy of 98,75% while the test accuracy was produced with an average accuracy of 98,89%.

The main nutritional components in colored rice grains

Colored rice grains contain rich nutrients. To investigate the differences in nutrient composition among different colored rice varieties, LC-MS non-targeted lipidomics and targeted amino acid profiling were used to study the lipid and amino acid composition in four colored rice grains. The study analyzed the relationship between amino acids, mineral elements, crude protein (CP), crude fat (CF), carotenoids (CAROT), vitamin C (ASA), ATP, total sugar (TS), soluble protein (SP), and metabolites. A total of 505 lipid metabolites were identified. The results depicted that YZ6H had the highest levels of Arg, Asn, Met, Orn, and Try. HN had the highest levels of GABA, His, Lys, Thr, Tyr, Val, and Tau, which were significantly higher than those in YZ6H, YJN818, and YCN1H. PC (16:0/16:1,16:1/18:2,18:1/14:1,18:1/14:0,18:1/18:1,18:0/18:1), TG (16:0/18:3/22:2,22:4/18:2/18:2,16:0/20:2/20:4), and PE(20:4e/15:0) were significantly negatively correlated with GABA, Leu, Lys, Thr, Tyr, Val, Gln, His, and Ile. TG(18:2/17:1/18:2,15:0/18:2/18:2,15:0/18:2/18:3,15:0/16:0/18:2,15:0/18:1/18:2,18:1/17:1/18:2,18:1/17:1/18:1,18:1/10:1/18:1) was significantly positively correlated with Pro and Tau. YZ6H had the highest levels of ASA, SP, TS, CAROT, and ATP content. PG(28:0/18:1), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), and LPC(16:0) TG(20:4e/18:3/20:1) were significantly negatively correlated with SP, CAROT. Hex1Cer(t18:1/24:0+O), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), LPC(16:0), TG(16:0/20:2/20:4,20:4e/18:3/20:1), and DG(18:1/14:0), which are key lipid metabolites involved in the synthesis of nutritional components in colored rice grains.

‘Dahongmi’, a Mid-Maturing, High-Yielding, Red-brown Colored Rice Cultivar with Improved Cultivation Stability

‘Dahongmi’, a Mid-Maturing, High-Yielding, Red-brown Colored Rice Cultivar with Improved Cultivation Stability

Anthocyanins-natural pigment of colored rice bran: Composition and biological activities

Rice by-products are a potential source of various bioactive substances with great processing potential, which are receiving increasing attention. Among them, rice bran is a by-product of rice milling, with high nutritional value and health benefits. Colored rice bran contains a large amount of anthocyanins responsible for color and bioactivities. And anthocyanins are often added to foods as a natural pigment, serving to enhance both the visual appeal and nutritional value. Recent advances in the composition and bioactivities of four common colored rice bran anthocyanins (black, purple, red, and purple red rice) are reviewed in this paper. Rice bran anthocyanins have been confirmed to exhibit biological potential for human health, with their main biological activities being antioxidant, anti-atherosclerosis, anti-cancer, neuroprotective, retinoprotective, immunomodulatory, anti-aging and anti-obesity effects. The structure of anthocyanins determines their biological activities. The anthocyanins composition of rice bran with different colors varied greatly, while that of rice bran with the same color is also slightly different, which is attributed to the rice varieties, growing environment and cropping conditions. However, it remains necessary to conduct further clinical studies to support the health activities of anthocyanins. The present review provides information value for the further development and comprehensive utilization of rice bran anthocyanins.

Untargeted Lipidomics Reveal Quality Changes in High-Moisture Japonica Brown Rice at Different Storage Temperatures.

Low temperatures are an effective way of delaying grain rancidity and deterioration. However, little is known about the difference in quality changes in high-moisture japonica brown rice at different storage temperatures. In this study, the storage quality changes in japonica brown rice with a 15.50% moisture content stored at 15 °C, 20 °C, and 25 °C were investigated. In addition, an untargeted lipidomics analysis coupled with gas chromatography and mass spectrometry (GC-MS) was applied to analyze the volatile compounds and metabolite changes in the high-moisture japonica brown rice. The results showed that storage at 15 °C could well maintain the color and aroma stability of the brown rice and delay the increase in fatty acid value (FAV). The lipidomics results showed that storage at 15 °C delayed glycerolipid and sphingolipid metabolism and reduced glycerophospholipid catabolism in the brown rice. The low-temperature environment regulated these three metabolic pathways to maintain higher contents of triglycerides (TG), phosphatidylserine (PS), abd phosphatidylethanolamine (PE), and lower contents of diglycerides (DG), OAcyl-(gamma-hydroxy) FA (OAHFA), ceramides (Cer), and glycosylceramides (Hex1Cer) in the high-moisture japonica brown rice, which maintained the storage stability of the brown rice. Our results proposed the cryoprotection mechanism of postharvest brown rice from the perspective of volatile compounds and metabolite changes, providing a foothold for the further exploration of low-temperature storage as a safe and efficient cryoprotectant in the grain storage field.