Showing papers on "Black rice published in 2019"

Phenolic profile and antioxidant activity of Chinese rice wine fermented with different rice materials and starters

Abstract: The polyphenolic compounds in wines are beneficial to human health. To better understand the effect of different factors on the phenolics and antioxidant activities of wine during rice wine fermentation, 6 rice materials and 7 rice wine starters from rural areas were used to ferment Chinese rice wine. The results showed that black rice and the starter O4 were preferred for the optimum polyphenolic content and antioxidant activity, respectively. In addition, the results indicated that the polyphenolics of the rice wines were mainly derived from their plant materials and that various rice materials could result in drastically different wine quality. In contrast, the total polyphenol contents could be less significantly changed by using different starters. The antioxidant activity results of these fermented wines were consistent with the results of the total polyphenol contents. The rice wines produced using 6 different rice materials were significantly different in antioxidant activity measured by ABTS and FRAP assay. Similar to the results of the total polyphenol content and the antioxidant activity, the wine samples with different rice materials showed significantly different polyphenolic profiles compared with those of the rice wine group with different starters. These results suggested that rice materials and starters have different effects on polyphenol extraction and conversion of rice wines.

Transcriptome and Proteome Profiling of Different Colored Rice Reveals Physiological Dynamics Involved in the Flavonoid Pathway.

Abstract: Black and red rice are rich in both anthocyanin and proanthocyanin content, which belong to a large class of flavonoids derived from a group of phenolic secondary metabolites. However, the molecular pathways and mechanisms underlying the flavonoid biosynthetic pathway are far from clear. Therefore, this study was undertaken to gain insight into physiological factors that are involved in the flavonoid biosynthetic pathway in rice cultivars with red, black, and white colors. RNA sequencing of caryopsis and isobaric tags for relative and absolute quantification (iTRAQ) analyses have generated a nearly complete catalog of mRNA and expressed proteins in different colored rice cultivars. A total of 31,700 genes were identified, of which 3417, 329, and 227 genes were found specific for red, white, and black rice, respectively. A total of 13,996 unique peptides corresponding to 3916 proteins were detected in the proteomes of black, white, and red rice. Coexpression network analyses of differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) among the different rice cultivars showed significant differences in photosynthesis and flavonoid biosynthesis pathways. Based on a differential enrichment analysis, 32 genes involved in the flavonoid biosynthesis pathway were detected, out of which only CHI, F3H, ANS, and FLS were detected by iTRAQ. Taken together, the results point to differences in flavonoid biosynthesis pathways among different colored rice cultivars, which may reflect differences in physiological functions. The differences in contents and types of flavonoids among the different colored rice cultivars are related to changes in base sequences of Os06G0162500, Os09G0455500, Os09G0455500, and Os10G0536400. Current findings expand and deepen our understanding of flavonoid biosynthesis and concurrently provides potential candidate genes for improving the nutritional qualities of rice.

Virtual Prediction of the Delphinidin-3-O-glucoside and Peonidin-3-O-glucoside as Anti-inflammatory of TNF-α Signaling

Abstract: Introduction Anthocyanin is the bioactive compound in black rice, which promotes some health benefits for human body. Present study revealed that black rice anthocyanins improve the biomarker of the metabolic syndrome, such as tumor necrosis factor alpha (TNF-α). However, the mechanism of anthocyanin in preventing metabolic syndrome has not been elucidated. Aim This study was performed to identify the interaction of six types of black rice anthocyanin towards TNF-α protein and TNF-α receptor through in silico studies, to assess the molecular properties and bioactivity of black rice anthocyanin. Methods We retrieved the black rice anthocyanin compounds from the PubChem database and the proteins (TNF-α protein and TNF-α receptor) from Protein Data Bank (PDB) database. Protein and ligands were docked using Hex 8.0 software and visualized by Discovery Studio 4.1 program. Results This study found the possibility that black rice anthocyanins interacted with TNF-α have no influence into TNF-α and TNF-α receptor interaction. The binding of delphinidin-3-O-glucoside & peonidin-3-O-glucoside to TNF-α receptor inhibited the TNF-α and TNF-α receptor signaling. The black rice anthocyanins had low activity as a drug. Interestingly, black rice anthocyanins had a potency as an antioxidant due to the hydrogen donor or acceptor in their structure, as protein kinase inhibitor, nuclear receptor ligand, and enzyme kinase inhibitor. Conclusion This study suggests that delphinidin-3-O-glucoside and peonidin-3-O-glucoside might have function as anti-inflammatory factor related with TNF-α signaling.

The effects of extruded black rice flour on rheological and structural properties of wheat‐based dough and bread quality

Abstract: Addition of raw black rice flour leads to deficient processability on bread making quality. One of the effective methods to modify the functional properties of black rice flour (BRF) composite dough is to extrude black rice flour (EBRF) before incorporation. This study investigated and compared the effect of BRF and EBRF addition level of 10%–50% on the rheology, microstructure of dough and bread quality. The rheological properties of composite dough were recorded by Mixolab, stress relaxation and tensile test. The substitution of EBRF presented higher water absorption but lower development time, protein weakening, starch gelatinization, starch gel stability and starch retrogradation than wheat flour dough. Both the BRF and EBRF dough presented solid‐like behaviour, while the EBRF dough showed more viscous, higher resistance and extensibility than BRF dough. The dough microstructure of dough was observed by SEM, and a more compact structure of EBRF dough could be seen than BRF dough. The incorporation of EBRF in bread quality presented higher specific volume, lower bake loss and firmness than BRF bread. These findings indicated the potential utilisation value of extruded black rice flour in bread making.

Study on Drying of Black Rice (Oryza sativa L.) Grains: Physical-Chemical and Bioactive Quality

Abstract: The present study aimed to assess the drying kinetics of black rice and fit different mathematical models (empirical and diffusive) to the experimental data, and evaluate the effect of drying air temperature on the physical-chemical and bioactive compounds quality of black rice. Drying air temperatures ranged from 40 to 80 oC and the drying air speed was 1.5 m/s. Physical-chemical characterization of the product was based on the following parameters: moisture, water activity, ashes, total protein content, pH, total acidity, lipids, total carbohydrates, total anthocyanins, flavonoids, total phenolic compounds and antioxidant activity. Among the empirical models, Page showed the lowest mean squared deviations (MSD) and highest coefficients of determination (R2). For the diffusion model, the values of effective mass diffusivity and convective heat transfer coefficient increased with increasing drying air temperature, and the Biot number indicated that the first-type boundary condition would also describe well the drying process. Physical-chemical parameters and bioactive compounds differed between the temperatures used, and the temperature of 60 oC led to the best relationship between drying time and preservation of product characteristics.

Evaluation of sensory, physicochemical properties and Consumer preference of black rice and their products.

Abstract: This study was aimed to evaluate the physicochemical, textural, sensory and antioxidative attributes of various rice products such as boiled rice, beaten rice, popped rice, puffed rice and raw milled rice, prepared from the Indian black rice cultivars Chakha (CH), Kalobhat (KB), Mamihunger (MA) and Manipuri Black (MN). A popular white rice variety Swarna Sub-1 (SW) was considered as control. Significant differences in most of the physicochemical and cooking parameters of raw rice were observed across different cultivars. The head rice recovery, amylose content, elongation ratio (ER) and kernel length after cooking of MA were most satisfactory among the black rice cultivars and are found to be 50.67%, 17.6%, 1.87 and 10.10 mm respectively, while popped rice of MA recorded highest length (10.83 mm) and elongation ratio (ER; 2.01). MA showed the highest adhesiveness (11.18 mJ) in boiled rice but hardness (183.53 N) was medium in raw rice. Other textural quality varied differentially according to the various products and cultivars. The highest a* value was obtained from puffed rice of MA (6.61) but L value was highest in raw rice of MN. Popped and boiled rice of MA displayed higher DPPH-antioxidant activity (88.74% and 84.74% respectively) as compared to all other products. The raw rice of KB registered higher anthocyanin (57.23 mg/100 g) content while boiled rice of SW recorded the least (0.21 mg/100 g). A survey on the consumer preference of these products indicated that boiled rice was usually preferred in lunch and dinner by most of the consumers whiles other products in breakfast. With respect to most of the traits, MA showed the good potential for rice Industry as well as for breeding material.

Effects of gamma radiation on the stability and degradation kinetics of phenolic compounds and antioxidant activity during storage of (Oryza sativa L.) black rice flour

Abstract: The effects of gamma radiation (0, 1, 2 and 3 kGy) were used to evaluate the stability and thermal degradation kinetics of anthocyanins, as well as the stability of total phenolic compounds (TPC) and antioxidant activity at different temperatures (4, 25, 35 and 45 °C) during the storage (0, 30, 60, 90 and 120 days) of black rice flour. This flour can be used as ingredient for gluten-free cereal products with higher nutritional value. For this it is necessary to preserve the anthocyanin content during thermal processing and shelf-life periods. At time 0, the dose of 3 kGy provided all of the most available bioactive compounds, raising their antioxidant potential, except for TPC. During the storage at different temperatures up to 120 days, gradual losses occurred in all the analysed parameters. Regarding the total anthocyanin content and TPC, the sample irradiated with a 1 kGy dose remained most stable. The analysis of kinetic data indicated a first-order reaction for the degradation of anthocyanins. The combination of irradiation with different temperatures may improve the shelf-life of black rice flour.

Milling and thermal treatment induced changes on phenolic components and antioxidant activities of pigmented rice flours.

Abstract: Processing methods involved in value addition to pigmented broken rice, a milling by-product may affect the nutraceutical qualities. Hence the effect of pulverisation and toasting on nutraceutical content in brown rice flours of red and black rice varieties were studied. Plate milling reduced soluble, bound and total polyphenols in red, but increased in black; increased insoluble polyphenols and oryzanol, and reduced anthocyanin in both varieties; antioxidant activity is reduced in red, but increased in black. Toasting caused reduction of soluble, insoluble and total polyphenol, anthocyanin and antioxidant activity in both varieties with an increase in bound polyphenols, and retention of flavonoids and oryzanol. HPLC characterization of phenolics showed changes on processing in content of catechin, caffeic, vanillic, protocatechuic and ferulic acid. It can be concluded that processing impacts the phenolic components of pigmented broken brown rice flour and this information is useful for functional food industry.

New Functional Ingredients Based on Microencapsulation of Aqueous Anthocyanin-Rich Extracts Derived from Black Rice (Oryza sativa L.).

Abstract: The aqueous anthocyanin-rich extract derived from black rice (Oryza sativa L.) was encapsulated by freeze drying using milk proteins and peptides as coating materials. The molecular modelling approach indicated that all major casein fractions and whey proteins were able to bind at least one anthocyanin molecule. The hydrophobic interactions and hydrogen bonding across the interfaces appeared to be mainly responsible for the stabilizations of the complexes formed between the coating material and bioactive compounds. Two dark purple colored powders, differentiated by the ratio of the encapsulation materials used, rich in phytochemicals were obtained, with an encapsulation efficiency of up to 99%. The powders were tested for antioxidant activity, cytocompatibility, and thermal stability. The morphological structure of the powders highlighted the presence of encapsulated anthocyanins. Both powders showed a remarkable antioxidant activity of about 46 mM Trolox/g D.W., and cytocompatibility on the L929 fibroblast culture. At certain concentrations, both powders stimulated cell proliferation. The powders showed a good thermal stability between 75 and 100 °C for 15 min. The powders were tested in a food model system and checked for stability of phytochemicals during storage. The added value of the powders was demonstrated throughout the antioxidant activity, which remained unchanged during storage.

The anti-inflammatory and antioxidant effects of pigmented rice consumption in an obese cohort

Abstract: The development of lifestyle diseases in the obese has been attributed to higher levels of inflammation and free radical mediated oxidative stress. The antioxidant and anti-inflammatory properties of polyphenols in pigmented rice varieties could have potential to neutralize oxidative stress and modulate inflammatory responses in the obese. A cross-over dietary intervention human clinical trial was conducted with three pigmented rice varieties chosen from previous chemical and in vitro antioxidant and anti-inflammatory screening. Obese (n = 22, BMI > 30) sedentary participants consumed one cup of pigmented rice (Reiziq (brown), Purple (purple) and Yunlu29 (red)). Blood samples were collected prior consumption (baseline) and at set time points of 30 minutes, 1 hour, 2 hours and 4 hours post rice consumption. The collected blood samples were analysed for antioxidant and inflammatory biomarkers. Total antioxidant activity increased (p < 0.001) at the 1 hour time point by 40.3% post purple rice consumption. The red rice variety, Yunlu29 increased antioxidant activity at the 30 minute (p < 0.001) and 1 hour (p < 0.01) time point by 29.5% and 21.2% respectively. Lipid peroxidation biomarker, malondialdehyde (MDA), decreased (p < 0.05) at the 30 minute time point by 6.8% post purple rice consumption. At the 4 hour time point MDA levels was significantly reduced (p < 0.001) by the red rice variety Yunlu29, by 9.6%. Pro-inflammatory cytokine, interleukin-10 (IL-10), was significantly (p < 0.0001) reduced by 3.1% 30 minutes post purple rice consumption. In contrast, Yunlu29 (red) reduced interleukin-6 levels by 13.6% and 11.0% at the 30 minute and 1 hour time points respectively. Both the purple (p < 0.01) and red (p < 0.001) varieties significantly reduced interleukin-12p70 concentrations at 30 minutes by 8.7% and 10.3% respectively. Reiziq (brown) did not affect any of the biomarkers analysed in this study. The outcomes of this study highlight that polyphenols found in pigmented rice may play a key role in targeting specific therapeutic pathways in obesity-related oxidative stress and inflammation.

Production of innovative gluten-free breakfast cereals based on red and black rice by extrusion processing technology.

Abstract: The transformation of black and red, broken or not, whole rice grains, into breakfast cereals is an interesting way to add value to these snacks for some reasons. Firstly, broken kernels hardly achieve a high market value; whole rice is healthy not only for their nutrient contents but also for their phytochemical profile, rich in phenolic compounds; breakfast cereals from pigmented rice are colored by themselves, and any additional colorant is unneeded; finally, rice is naturally gluten-free and suitable for those with conditions like celiac disease or gluten sensitivity. The objective of this study was to optimize some extrusion parameters that account for the physicochemical properties of extrudates by using response surface methodology. Feed moisture between 15 and 21% and the 4th barrel zone temperature between 110 and 160 °C were the independent variables. Specific features such as color, texture, water solubility and absorption, cold viscosity, expansion, specific volume, and compression force were evaluated. The trials have shown that moisture had a higher impact on the extrusion process than temperature. Less expanded, denser, harder, and darker products were obtained at higher moisture levels. The optimum points were defined at 15.5% and 16.0% of feed moisture and 159 °C and 150 °C of temperature for black and red rice extrudates, respectively. These conditions resulted in cereal breakfast balls with optimal water solubility, volume, texture, and good color. Additionally, cold viscosities and a low compression led to products with a potential high approval by consumers.

Induced Mutation for Genetic Improvement in Black Rice Using Gamma-Ray

Abstract: Black Rice is rice producing anthocyanin in high intensity and popularly consumed as functional food. Long harvesting age and low productivity are the inhibiting factors in black rice breeding. High plant crown potentially results in plant fall-down. Mutation induction is expected to be able to improve the character of black rice. Therefore, the objectives of this research were to get more early-ripening black rice mutant, with shorter plant crown and increase productivity by inducing mutation in three varieties of local black rice using gamma-ray radiation. This experiment employed three local varieties as the first factor comprised Cempo Ireng, Cempo Melik and Melik. The second factor was the gamma-ray radiation dose, consisting of 4 levels: without radiation, radiations at 100 Gy, 200 Gy and 300 Gy doses. The results indicated that Melik variety is very potential. Melik variety has shorter plant crown with a responsive character in number of tiller for higher productivity. Moreover, radiation significantly reduces the duration of flowering and harvesting. However, to achieve a more stable character and lower flowering and harvesting period, the radiation needs to be continued in the next generation. The doses of radiation produces a response that varies in both morphological and biochemical properties.

Glycemic Index of Flakes Made from Mocaf-Black Rice and Bean Flour as Alternative Snacks for People with Type 2 Diabetes Mellitus

Abstract: This study aimed to analyze the glycemic index and glycemic load of mocaf-black rice flakes. The study used a single-factor completely randomized design in which the type of bean flour added were black soybean flour and jack bean flour. The glycemic index was analyzed using the incremental area under the blood glucose response curve (IAUC) method. The glycemic index and glycemic load data were analyzed using paired T-test. The results showed that mocaf-black rice flakes with the addition of black soybean flour and jack bean flour had glycemic indexes of 50,19±21,57; 52,59±22,93 and glycemic loads of 13,75±5,91; 14,60±6,37, respectively. Both flakes can be recommended as snacks for people with type 2 diabetes.

Stabilization of Black Rice (Oryza Sativa, L. Indica) Anthocyanins Using Plant Extracts for Copigmentation and Maltodextrin for Encapsulation

Abstract: Black rice (Oryza sativa L. indica) is one of the cereal commodities considered to be a source of anthocyanin. One of the obstacles of using anthocyanins as natural food colorants is their low stability. The objective of this study was to determine the effect of natural plants extracts on anthocyanin copigmentation and to study the stability of the encapsulated copigmented anthocyanin during storage under different temperatures and light exposure. Dried bilimbi leaves (BL) and sow thistle leaves (STL) were extracted using ethanol to obtain the crude flavonoid extract that was subsequently purified using solid phase extraction. Both crude (CBL, CSTL) and purified (PBL, PSTL) extract were used as copigment agents with the molar ratio of 1:0.1 to 1:10 at pH 1 and pH 3. The copigmentation effect was evaluated by measuring the wavelength and absorbance shifts at wavelengths of 500 to 600 nm. The stability of the dried anthocyanin powder was evaluated under different temperatures and light exposure for up to 4 weeks. Anthocyanin was successfully copigmented with BL and STL extracts showing a wavelength shift and absorbance increase at pH 1 and pH 3. Purification of BL enhanced the hyperchromic effect more than that of the crude form, in contrast to the STL. Meanwhile, the retention of absorbance (%) for encapsulated copigmented anthocyanin samples was within 74% to 83% at the end of the storage period. PRACTICAL APPLICATION: Natural food pigment such as anthocyanin obtained from plant extract usually shows very limited stability under various processing conditions. This study shows that color stability of anthocyanin extracted from black rice can be improved by copigmentation with flavonoids extracted from particular plants. Encapsulation of the copigmented anthocyanin could further enhance its color stability. The availability of encapsulated and copigmented anthocyanins with improved color stability is expected to provide more alternatives for especially the beverage industry to choose suitable natural colorant for their products.

Farmers Drive Genetic Diversity of Thai Purple Rice ( Oryza sativa L.) Landraces

Abstract: Purple or black rice (Oryza sativa L.) is a culturally important germplasm in Asia with a long history of cultivation in northern Thailand. Purple rice is identified by the color of the rice pericarp, which varies from purple to black with the accumulation of phenolic acids, flavonoids, and anthocyanins. In the present study, we assessed molecular variation within and between wetland purple rice landraces germplasm from northern and northeastern Thailand using 12 microsatellite loci. All purple rice varieties surveyed showed high levels of homozygosity within varieties and strong genetic differentiation among varieties, indicating the fixation of genetic differences among them. This pattern is consistent with purple rice farming practices in northern Thailand, where a small portion of harvested seed is selected and replanted based on farmers’ preferences. The reduced genetic diversity and high homozygosity observed for purple rice is also consistent with patterns expected for this inbreeding crop. Genetic differentiation among the varieties showed some degree of structuring based on their geographical origin. Taken together, these data highlight that the genetic diversity and structure of wetland purple rice landraces is shaped by farmer utilization and cultivation through local cultural practices, and that conservation should focus on ex situ conservation across its cultivation range, along with on-farm, in situ conservation based on farmers’ seed-saving practices. In situ conservation may prove especially valuable for preserving the genetic identity of local varieties and promote adaptation to local environments.

The Effect of Stable Manure and Seedling Number on Growth and Yield of Black Rice (Oryza sativa L. Indica)

Abstract: Black rice is one of fungtional food sources. The obstacle of its cultivation is availability of qualified seeds and organic fertilizers input. This research aimed to determine the effect of stable manure on growth and yield of black rice, to observe the effect of seddling number per planting hole and to obtain the best combination of stable manure and seedling number on the growth and yield of black rice. The research was conduct in rice field on Karanglewas Kidul village, Karanglewas district, Banyumas, Central Java during April until September 2016. This research used a split plot design, with 3 repetition. The main plot was three type of stable manure (chiken, goat and cow), while the subplot was seddling number (1, 2 and 3). Data was analyzed using ANOVA and DMRT at p 0.05 level. The results showed that chicken manure gave the highest productivity rice of 5.15 tons ha -1 . The 1 seedling each hole gave the highest result on panicle length and grain number per panicle. The better combination treatment was chicken manure and three seedling per planting hole wich gave the highest grain yield of 5.38 tons ha -1 .