Showing papers on "Black rice published in 2018"
TL;DR: This study found much wider diversity in the phenolics and antioxidant capacity in the whole grain and brans of rice, and will provide new opportunities to further improvement of rice with enhanced levels of the phytochemicals.
193 citations
TL;DR: Non-pigmented rice had no detectable conjugated protocatechuic and 2,5-dihydroxybenzoic acids both of which were found in black and red rice, respectively, andTPAC was positively correlated with a∗ (P<0.01), while TPAC was negatively correlated with L∗, b ∗, C and H° values.
142 citations
TL;DR: Black rice bran contains high levels of phytochemicals, and thus has potent pharmaceutical activity, which highlights opportunities for researcher to breed new genotypes of rice with higher nutritional values, which the food industry can use to develop new products that will compete in expanding functional food markets.
Abstract: In the recent years, the health benefits of the pigmented rice varieties have reported due to the presence of bioactive compounds. In this study, the phytochemical constituents (total phenolic, flavonoid and anthocyanin content) and individual phenolics and flavonoids of the extracts of sixteen genotypes of pigmented rice bran were evaluated using spectrophotometric and ultra-high performance liquid chromatography method. Antioxidative properties of the free and bound fractions were evaluated using nitric oxide and 1,1-diphenyl-2-picrylhydrazyl scavenging assays. Extracts were evaluated for antiproliferative activity against breast cancer cell lines (MCF-7 and MDA-MB-231) using the MTT assay. Signifficant diferences were observed in the concentrations of phytochemicals and biological activities among different pigmented rice brans. The highest phytochemical content was observed in black rice bran followed by red and brown rice bran. The concentration of free individual flavonoids and phenolic compounds were significantly higher than those of bound compounds except those of ferulic acid and p-coumaric acid. Highest antioxidant activities were observed in black rice bran, followed by red and brown rice bran extracts. Extracts of black rice bran exhibited potent antiproliferative activity, with half maximal inhibitory concentrations (IC50) of 148.6 and 119.2 mg/mL against MCF-7 and MDA-MB-231 cell lines, respectively, compared to the activity of the extracts of red rice bran (175.0 and 151.0 mg/mL, respectively) and brown rice bran (382.3 and 346.1 mg/mL, respectively). Black rice bran contains high levels of phytochemicals, and thus has potent pharmaceutical activity. This highlights opportunities for researcher to breed new genotypes of rice with higher nutritional values, which the food industry can use to develop new products that will compete in expanding functional food markets.
96 citations
TL;DR: The results revealed that the Anthocyanins and anthocyanin monomers from black rice had prebiotic activity and they were metabolized into several small molecules by Bifidobacteria and Lactobacillus.
Abstract: Anthocyanins are naturally active substances. In this study, anthocyanins from black rice were obtained by membrane filtration and column chromatography separation. Five anthocyanin monomers in black rice extract were identified by HPLC-MS/MS, and the major anthocyanin monomer (cyanidin-3-glucoside, C3G) was purified by preparative HPLC (Pre-HPLC). The proliferative effects of the anthocyanins on Bifidobacteria and Lactobacillus were investigated by determining the media pH, bacterial populations and metabolic products. After anaerobic incubation at 37 °C for 48 h, not only the pH of the media containing C3G was lower than that of the extract of black rice anthocyanin (BRAE), but the numbers of both Bifidobacteria and Lactobacillus were also significantly increased. Furthermore, hydroxyphenylpropionic, hydroxyphenylacetic, and hydroxybenzoic acids and other metabolites were detected by GC-MS in vitro. Our results revealed that the anthocyanins and anthocyanin monomers from black rice had prebiotic activity and they were metabolized into several small molecules by Bifidobacteria and Lactobacillus.
76 citations
TL;DR: Cyanidin-3-O-glucoside was the most potent anthocyanin on kinase inhibition and tyrosine kinase inhibitory potential in silico and biochemically.
74 citations
TL;DR: In this paper, free and bound phenolic extracts from three varieties of black, indica, and Japonica rice bran were evaluated for their compositions, antioxidant activity and inhibitory effects on amylase and glucosidase activities.
53 citations
TL;DR: The polyphenolic extract obtained from Artemide black rice can be considered a valuable source of polyphenols to produce functional foods or microencapsulated ingredients for nutraceutical applications.
52 citations
TL;DR: In rye, recessive mutations in six genes lead to the absence of anthocyanins in all parts of the plant, which will provide a perspective for future investigations on similar data in rice, barley, and wheat.
Abstract: The color of grain in cereals is determined mainly by anthocyanin pigments. A large level of genetic diversity for anthocyanin content and composition in the grain of different species was observed. In rye, recessive mutations in six genes (vi1...vi6) lead to the absence of anthocyanins in all parts of the plant. Moreover, dominant genes of anthocyanin synthesis in aleurone (gene C) and pericarp (gene Vs) also affect the color of the grain. Reverse phase high-performance liquid chromatography and mass spectrometry were used to study anthocyanins in 24 rye samples. A lack of anthocyanins in the lines with yellow and brown grain was determined. Delphinidin rutinoside and cyanidin rutinoside were found in the green-seeded lines. Six samples with violet grains significantly varied in terms of anthocyanin composition and content. However, the main aglycone was cyanidin or peonidin in all of them. Monosaccharide glucose and disaccharide rutinose served as the glycoside units. Violet-seeded accession forms differ in the ratio of the main anthocyanins and the range of their acylated derivatives. The acyl groups were presented mainly by radicals of malonic and sinapic acids. For the colored forms, a profile of the revealed anthocyanins with the indication of their contents was given. The obtained results are discussed in connection to similar data in rice, barley, and wheat, which will provide a perspective for future investigations.
31 citations
TL;DR: Colored rice grains have high potential to be used as antioxidant sources in addition to starch sources in ruminants and are ranked among commonly used grains: wheat>barley ≥rice>maize.
Abstract: Objective An experiment was conducted to assess the antioxidant contents and activities of colored rice grains and to evaluate their nutritive characteristics in terms of chemical composition and in situ ruminal degradation. Methods Ten cultivars of colored rice grains (Oryza sativa L.) collected from several areas of Japan were studied, and control rice without pigment, maize, barley, and wheat grains were used as control grains. Their chemical compositions, pigment, polyphenol contents, total antioxidant capacity (TAC), and degradation characteristics were determined. Results The starch contents of the colored rice grains were in the range of 73.5% to 79.6%, similar to that of the control rice grain. The black and red rice grains contained anthocyanin (maximum: 5,045.6 μg/g) and proanthocyanidin (maximum: 3,060.6 μg/g) at high concentrations as their principal pigments, respectively. There were significantly (pl0.05) positive relationships among the pigment contents, polyphenol content, and TAC values in the colored and control rice grains, indicating that the increase in pigment contents also contributed to the increased polyphenol content and TAC values in the colored rice grains. The dry matter and starch degradation characteristics, as represented by c (fractional degradation rate of slowly degradable fraction) and by the effective degradability, of the colored rice grains and the control rice grain were ranked as follows among commonly used grains: wheatgbarley ≥ricegmaize. The colored rice grains also included the most-digestible starch, since their potential degradable fraction and actual degradability at 48 h incubation were almost 100%. Conclusion Colored rice grains have high potential to be used as antioxidant sources in addition to starch sources in ruminants.
30 citations
TL;DR: The results demonstrated that explosion puffing is a suitable technique to improve the physical properties and digestibility of grains, which provided the theoretic foundation for the use of explosionpuffing technology in coarse cereal processing.
Abstract: The objective of this study was to investigate the effects of explosion puffing on the nutritional composition, physical properties, and digestibility of grains including millet, barley, black rice...
28 citations
TL;DR: The results showed that the die pressure significantly decreased with the increasing extrusion temperature, and the expansion ratio reached a peak value at 100 °C, whereas the soluble-free and total phenolic acid contents gradually increased as mentioned in this paper.
Abstract: Different extrusion temperatures (90, 100, 110, and 120 °C) were used to investigate changes in the expansion ratios, die pressures, phytochemical contents and antioxidant activities of extrusion products of black rice. The results showed that the die pressure significantly decreased with the increasing extrusion temperature, and the expansion ratio reached a peak value at 100 °C. The soluble-free and total phenolic acid contents gradually increased, whereas portions of soluble-free and soluble-conjugated phenolic acids transformed into insoluble-bound phenolic acids. The soluble-free (52.45) and insoluble-bound (73.59 mg GAE/100 g DF) total phenolic contents (TPC) reached peak values at 110 °C. The soluble-conjugated TPC values remained similar. Antioxidant activity occurred at higher levels in the range from 100 °C to 120 °C. The anthocyanin content decreased after extrusion possibly because some anthocyanin remained in the residue after extraction and could not be completely extracted. The content of free sterols increased from 90 °C to 110 °C and decreased at 120 °C. However, the content of bound sterols showed an opposite trend and reached a minimum value at 110 °C.
TL;DR: The findings emphasize the need to identify and develop rice with high RS and low GI, which can be further reduced by combining with suitable pulses and oil/fat.
TL;DR: In this paper, a total of 101 volatile compounds were found in raw and cooked black rice (cv. Sintoheugmi) samples with different degrees of milling (step 0, 0%; step 1, 4.2%; and step 2, 10.5%).
Abstract: Volatile compounds in raw and cooked black rice (cv. Sintoheugmi) samples with different degrees of milling (step 0, 0%; step 1, 4.2%; and step 2, 10.5%, w/w) were investigated by headspace solid-phase microextraction and gas chromatography–mass spectrometry. A total of 101 volatile compounds were found. Among them, 44 compounds found in raw black rice were absent in cooked black rice and 20 compounds were newly formed in cooked black rice. The 8 identified major odor-active volatile compounds in raw and cooked black rice included 3 phenols (guaiacol, 4-vinylphenol, and 2-methoxy-4-vinylphenol), 2 benzenes (benzaldehyde and p-xylene), 2 furans (2-butylfuran and 2-pentylfuran), and 1 terpene (calamenene). Additionally, fatty acid oxidation products such as hexanal, 2-nonenal, octanal, and 2-pentylfuran were found in raw and cooked black rice samples. The relative concentrations of these volatile compounds were significantly higher in step 0 than in step 2 of raw and cooked black rice (p < 0.05). Partially milled cooked black rice (i.e., step 1) contained ~ 80% guaiacol (a favorable unique black rice flavor) of unpolished rice (step 0), with similar levels of several lipid oxidation indicator volatile products (e.g., 2-nonenal and 2-pentyl furan) of fully milled rice (step 2). Thus, partially milled black rice should be consumed rather than fully milled black rice.
TL;DR: In this article, the authors evaluated the effect of different milling degrees and cultivars of black rice (Oryza sativa L.) on the total phenolic contents (TPC), total flavonoid contents, antioxidant activity, phenolic acid levels, and anthocyanin levels.
Abstract: Six black rice cultivars (Heukjinju, Sintoheugmi, Heukhyangchal 1, Bosukheukchal, Sinnongheukchal, and Josengheukchal) and varying milling degrees (step 0, 0%; step 1, 4.2%; and step 2, 10.5%, w/w) were used to evaluate the effects of cultivars and milling degrees of black rice (Oryza sativa L.) on the total phenolic contents (TPC), total flavonoid contents (TFC), antioxidant activity (2,2-diphenyl-1-picrylhydrazyl free radical assay), and phenolic composition in free and bound phenolic fractions. Unpolished (step 0) Sintoheugmi showed significantly higher TPC, TFC, antioxidant activity, phenolic acid levels, and anthocyanin levels than other unpolished cultivars (p < 0.05). As milling degree increased, TPC, TFC, antioxidant activity, phenolic acid levels, and anthocyanin levels decreased significantly (p < 0.05). TPC, TFC, and antioxidant activity were significantly higher in free phenolic fractions than bound phenolic fractions of black rice extracts, regardless of cultivars (p < 0.05). The major phenolic acid was ferulic acid, and the major anthocyanin found in free phenolic fractions in black rice samples was cyanidin-3-O-glucoside. The sum of individual phenolic acid levels (255.2 ± 0.0 μg/g) and the sum of anthocyanins levels (831.4 ± 0.3 μg/g) were significantly higher in Sintoheugmi black rice than in the other cultivars for step 0 (unpolished rice) (p < 0.05). For step 1 and step 2, Heukjinju black rice contained significantly higher sum of phenolic acid levels and sum of anthocyanin levels than the other cultivars (p < 0.05). For use as a better functional ingredient, it is, therefore, important to consider different milling degrees together with different black rice cultivars having the highest antioxidant component.
01 Mar 2018
TL;DR: In this article, the effect of optical properties of anthocyanin dyes on the efficiency of dye-sensitized solar cells was investigated, and the results showed that the red cabbage sensitizer showed lower absorbance value in the visible range (450-580 nm) than dragon fruit and black rice.
Abstract: Dye-sensitized solar cell (DSSC) is one of the alternative energy that can convert light energy into electrical energy. The component of DSSC consists of FTO substrates, TiO2, electrolyte, dye sensitizer, and counter electrode. This study aim was to determine the effect of optical properties of anthocyanin dyes on efficiency of DSSC. The dye sensitizer used can be extracted from anthocyanin pigments such as dragon fruit, black rice, and red cabbage. The red cabbage sensitizer shows lower absorbance value in the visible range (450-580 nm), than dragon fruit and black rice. The chemical structure of each dye molecules has an R group (carbonyl and hydroxyl) that forms a bond with the oxide layer. Red cabbage dye cell has the highest efficiency, 0.06% then dragon fruit and black rice, 0.02% and 0.03%.
07 Feb 2018
TL;DR: It is suggested that these nine identified genes appear to be related to the regulation of anthocyanin biosynthesis and/or metabolism as well as four phylogenetic groups from these nine candidate genes and 51 pathway-network genes.
Abstract: Anthocyanins are involved in many diverse functions in rice, but their benefits have yet to be clearly demonstrated. Our objective in this study was to identify anthocyanin-related genes in black rice plants. We identified anthocyanin-related genes in black rice plants using a combination of whole-genome resequencing, RNA-sequencing (RNA-seq), microarray experiments, and reverse-transcriptase polymerase chain reaction (RT-PCR). Using multi-layer screening from 30 rice accessions, we identified 172,922 single-nucleotide polymorphisms (SNPs) and 1276 differentially expressed genes that appear to be related to anthocyanin biosynthesis. We identified 18 putative genes from 172,922 SNPs using intensive selective sweeps. The 18 candidate genes identified from SNPs were not significantly correlated with the RNA-seq expression pattern or other well-known anthocyanin biosynthesis/metabolism genes. We also identified nine putative genes from 1276 differentially expressed genes using RNA-seq transcriptome analysis. In addition, we identified four phylogenetic groups from these nine candidate genes and 51 pathway-network genes. Finally, we verified nine anthocyanin-related genes using a newly designed microarray and semi-quantitative RT-PCR. We suggest that these nine identified genes appear to be related to the regulation of anthocyanin biosynthesis and/or metabolism.
TL;DR: The effects of different doses of gamma radiation on the thermoanalytical, structural and pasting properties of black rice (Oryza sativa L.) flour were studied using thermogravimetry and derivative thermograimetry (TG-DTG), differential scanning calorimetry, X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM) and RVA analysis.
Abstract: The effects of different doses of gamma radiation on the thermoanalytical, structural and pasting properties of black rice (Oryza sativa L.) flour were studied using thermogravimetry and derivative thermogravimetry (TG–DTG), differential scanning calorimetry, X-ray diffraction (XRD), field emission gun–scanning electron microscopy (FEG–SEM) and pasting properties (RVA) analysis. The thermogravimetric curves showed four mass losses. A small displacement was observed for the second loss, which occurred for the irradiated flours, compared to the control sample. The irradiated samples showed a slight decrease in the thermal parameters: initial temperature (T
o), peak temperature (T
p) and gelatinisation enthalpy (△H). All the black rice flours exhibited A-type crystallinity pattern, and the gamma radiation did not change the XRD patterns or the degree of crystallinity. The micro-images obtained using FEG–SEM showed a composite of organic and heterogeneous material; after gamma radiation, some changes occurred, such as cracks, pores and smaller fragments. The pasting properties decreased significantly with irradiation. The decrease in setback and breakdown viscosity after irradiation suggested an indication that it may be possible to improve the quality of food based on black rice flours. Gamma radiation can be a useful tool to modify rice flours in order to suit various functionalities and to help meet the growing demands of the food industry.
TL;DR: The inorganic arsenic contents in microwavable ready-to-eat rice products and different types of Korean rice were determined by a gas chromatography-tandem mass spectrometry (GC-MS/MS), which showed low limit of detection, high intra- and inter-day repeatability, and recovery rates.
TL;DR: RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice.
Abstract: Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO2 extraction (SC-CO2) Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice) RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3 Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO2 and SE methods, respectively In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best
TL;DR: Results suggest a neuroprotective effect of red and black rice brans extracts due to their high antioxidant capacity, along with the absence of cytotoxicity, and they may potentially be used as sources of bioactive compounds.
TL;DR: In this article, the extraction process of phenolic contents from black and purple rice bran in acetone, ethanol, and water, was optimized using rotatable central composite design (RCCD).
Abstract: The extraction process of phenolic contents from black and purple rice bran in acetone, ethanol, and water, was optimized using rotatable central composite design (RCCD). Results of the study suggested that ethanol was the most efficient solvent to extract total phenolic content (TPC) from rice bran. The optimal condition for extraction of TPC from purple rice bran was, 43.74% (v/v) ethanol concentration, 37.5 °C temperature, 22.5 min extraction time and 8.75 (mL/g) solvent to solid ratio. Whereas, for black rice bran, except solvent to solid ratio (8.80 mL/g), the optimal condition was same as purple rice bran. TPC was found to be higher in purple rice bran extract than black rice bran extracts at optimum condition. RCCD data was successfully used to predict the extraction yield using the artificial neural network. The purple rice bran extract shows a promisingly higher amount of phytochemical content in term of TPC, flavonoid, anthocyanins and phenolic acid than black rice bran extract. The purple rice bran extract also showed the higher antioxidant activity than black rice bran extract.
TL;DR: The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.
Abstract: Effects of partial (50%) and total replacement of wheat flour with black rice flour on the phytochemical, physico-chemical, sensorial, and textural properties of muffins were studied. Partial or total replacement of wheat flour with black rice flour in muffins improved their nutritional and antioxidative properties with a positive effect on microbiological and color stability during the storage period in accelerated conditions. The low gluten muffins had an anthocyanin content of 27.54 ± 2.22 mg cyanidin-3-glucoside (C3G)/100 g dry weight (DW), whereas the gluten free muffins had 46.11 ± 3.91 mg C3G/100 g DW, with significant antioxidant values. Retention of 60% and 64% for anthocyanins and 72% and 80% for antioxidant activity after baking was found. The fracturability and hardness scores increased with the addition of black rice flour, whereas firmness and chewiness increased for gluten free muffins. The confocal analysis revealed a tendency of glucidic components to aggregate, with gathers of small bunches of black rice starch granules comprising anthocyanin. The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.
TL;DR: This research focuses on screening local Indonesian black rice cultivars for resistance against BLB and analyzing the expression of these resistance genes in black rice after inoculation with Xoo, and indicated Cempo Ireng as the most resistant cultivar againstBLB disease.
Abstract: Black rice production in Indonesia constrained by the bacterial blight disease (BLB) caused by Xanthomonas oryzae pv. oryzae pathotype IV (Xoo). Breeding of BLB resistant cultivars is considered the most sustainable method for BLB disease control, both from an environmental and agricultural perspective. Indonesia has many local black rice varieties that can be used as genes resource to support breeding program producing resistant cultivars. The present research focuses on screening local Indonesian black rice cultivars for resistance against BLB and analyzing the expression of these resistance genes in black rice after inoculation with Xoo. The black rice cultivars Cempo Ireng, Pari Ireng, Melik, Pendek, and Indmira, were inoculated with Xoo while white rice cv. Conde, IRBB21, IR64, and Java14 were used as controls. We assayed the phenotypic performance of the cultivars samples after Xoo inoculation and analyzed their resistance gene expression at 24 and 96 h after Xoo inoculation semiquantitatively. The cultivar showed the best performance was selected for further analysis of the resistance genes using Real-time quantitative PCR. Cempo Ireng was indicated the most resistant cultivar against BLB disease based on the lowest disease intensity and Area Under Disease Progress Curve (AUDPC) value. Cempo Ireng expressed resistant genes xa5, Xa10, Xa21 and RPP13-like after inoculation of Xoo. The expression of xa5, Xa10, and Xa21 was up-regulated while that of RPP13-like was down-regulated in Cempo Ireng.
01 Oct 2018
TL;DR: In this article, the authors described indigenous agro-ecological knowledge and socio-cultural practices of Meitei farmers associated with black rice cultivation and identified a total of 72 knowledge holders through chain referral method in three representative villages in Imphal East district of Manipur.
Abstract: Chakhao (Black rice; Oryza sativa L.) is one of the lesser known traditional rice varieties of Manipur which provides not only nutraceutical benefits, but also plays a significant role in socio-cultural practices of the local Meitei community. This paper describes indigenous agro-ecological knowledge and socio-cultural practices of Meitei farmers associated with black rice cultivation. A total of 72 knowledge holders were identified through chain referrals method in three representative villages in Imphal East district of Manipur. Semi-directive interview and group discussion methods were employed for documentation of their knowledge and socio-cultural practices. In all four black rice landraces (viz., Chakhao poireiton, Chakhao angouba, Chakhao amubi and Chakhao pungdol amubi) were recorded in the study area. About 57 % of the farmers in the study area cultivated black rice in < 10 % of their land holdings. According to the farmers all these landraces of black rice are relatively stress tolerant and disease resistant and require less care and energy inputs. Black rice is used in different religio-cultural feasts and rituals of Meiteis. Beside it is also used as a medicine for diabetic patients and traditionally given to pregnant women. Cultural practices of Meiteis help conserving the agro-biodiversity in the study area.
TL;DR: In this article, several lipids and water-soluble metabolites from white, red, and black rice were analyzed using HPLC-DAD, GC-FID, and GC-MS/MS.
Abstract: In the present study, several lipids- and water-soluble metabolites from white, red, and black rice were analyzed using HPLC–DAD, GC–FID, and GC–MS/MS. The quantitative data showed that black rice contains the highest amount of cyanidin (4.34 mg/g), γ-oryzanol (380.2 µg/g), total folate (39.1 µg/100 g), tocols (tocopherols and tocotrienols; 21.7 µg/g), all-E-lutein (7.14 µg/g), polyunsaturated fatty acids (37.7%), and total phenolic contents (4.88 mg gallic acid eq./g). Additionally, the ascorbic acid equivalent (AAE) antioxidant assays showed that the metabolites from black rice were potent scavengers of ABTS cations (18.99 mg AAE/g) and DPPH radicals (16.20 mg AAE/g), probably because of the presence of high contents of phenolic (e.g., anthocyanin) and non-phenolic compounds (e.g., carotenoids, tocols, and γ-oryzanols). Among the studied metabolites, the least variation was recorded for fatty acid composition. In the three types of rice grains, oleic acid (C18:1n9c) was found in the highest quantity (38.60–40.35%), followed by linoleic (LA; C18:2n6c) and palmitic acid (C16:0) (18.90–21.15%). Overall, black rice was found to be the most abundant source of nutritionally important compounds, followed by red rice and white rice. Thus, this study provides a basis for the incorporation of pigmented rice into our daily diet for potential health benefits.
TL;DR: In this article, the anthocyanin, antioxidant activity, and macro-and micronutrients contents of black rice bran from Sleman, Yogyakarta were investigated.
Abstract: The chemical contents and health benefits of black rice bran of some rice cultivars have been investigated. However, there has been little research on the ‘Cempo Ireng’ cultivar from Sleman, Yogyakarta. The aim of this present study was to determine the anthocyanin, antioxidant activity, and macro- and micronutrients contents of black rice bran from this local cultivar. The anthocyanin in the black rice bran was extracted using the maceration method with methanol as a solvent. The extract obtained was separated through a preparative thin layer chromatography (TLC) of silica GF254 and a mobile phase composed of n-butanol, acetic acid, and water. Two fractions were collected and analyzed for the anthocyanin content. The preparative TLC spots were separated for further detection and measurement of cyanidin 3-O-glucoside using HPLC followed by LC-MS. The antioxidant activity of the fractions were measured using the DPPH free radical scavenging method. The results showed that the anthocyanin in fraction 1 was identified as cyanidin 3-O-glucoside (66.1 ± 10.6 µg/g). The IC 50 of fractions 1 and 2 were 200.96 and 218.36 µg/mL, respectively. Analysis of the macro- and micronutrients revealed that the black rice bran of ‘Cempo Ireng’ had nutrient contents comparable with other rice cultivars. Therefore, this local black rice bran can be used as a source of antioxidants and macro-- and micronutrients.
TL;DR: In this paper, the authors compared the metabolite profiles of black and red rice using the orthogonal partial least squares-discriminant analysis (OPLS-DA) model.
Abstract: Pigmented rice may have a black or red color due to higher anthocyanin content in its grain A natural antioxidant, many studies on anthocyanin have reported its positive effects on human health This fact has spurred the development of pigmented rice as a functional food This study aimed to compare the metabolite profiles of black and red rice Three black rice cultivars, namely Melik, Pari Ireng, and Cempo Ireng Sleman, and two red rice cultivars, Inpari 24 and RC 204, were used After husk removal, grain samples were ground in liquid nitrogen and dried with a freeze dryer The dried samples were extracted using 50% MeOD4 (in a D 2 O phosphate buffer pH 6 containing 001% TSP as an internal standard) Metabolomic analysis was performed using 500 MHz NMR followed by multivariate data analysis An orthogonal partial least squares-discriminant analysis (OPLS-DA) model ađer PCA was constructed to discriminate between the five different cultivars The resulting OPLS-DA score plot revealed a clear separation between black rice and red rice The metabolites that could influence the separation of red rice and black rice were valine, threonine, alanine, glutamate, galactinol, β-glucose, α-glucose, raffinose, and fumaric acid