Pigmented Rice Cultivars Research Articles

Evaluation of Physical, Thermal, Pasting Characteristics and Mineral Profile of Pigmented and Nonpigmented Rice Cultivars

Evaluation of Physical, Thermal, Pasting Characteristics and Mineral Profile of Pigmented and Nonpigmented Rice Cultivars

Phytochemical and Antioxidant Profile of Pigmented and Non-Pigmented Rice Cultivars of Arunachal Pradesh, India

This study was carried out to determine the phytochemical and antioxidant properties of two pigmented rice cultivars viz., Lingkang taker ame, Umling ame, and a non-pigmented rice Pungpo taker ame. Fourier transform infrared and high-performance liquid chromatography analysis of phenolic compounds were carried out for the rice cultivars. The highest level of total phenolic, anthocyanin, and scavenging activities were observed in Umling ame cultivar. Fourier transform infrared result of rice cultivars showed wide range of frequency (1131.60–3538.75 cm–1) which confirmed the presence of various phenolic compounds. Seven phenolic acids were detected in the rice cultivars. The highest value of salicylic acid (302.06 ± 0.01 mg/L), ferulic acid (17.21 ± 0.02 mg/L), apigenin (7.03 ± 0.01 mg/L), and gallic acid (0.98 ± 0.04 mg/L) were detected in Umling ame; whereas the highest value of quercetin (611.46 ± 0.01 mg/L) and caffeic acid (1.83 ± 0.01 mg/L) were found in Pungpo taker ame and Lingkang taker ame cultivars, respectively. Results revealed that the colored rice Umling ame showed higher phenolic content than other two rice cultivars Lingkang taker ame and Pungpo taker ame.

Status in physical properties of coloured rice varieties before and after inducing retro-gradation.

Three varieties of paddy in brown, red (non-waxy) and black (waxy) forms were de-husked and milled before and after inducing retro-gradation and their physical properties were studied. Normalized grain weight, porosity of parboiled paddy (PP) and its de-husked rice (DR), were high compared to their respective native. True and bulk density were lowest for black variety, its DR, its raw and parboiled forms compared to other varieties of paddy. Angle of repose increased from raw paddy to PP whereas it decreased from raw DR to parboiled DR. Under similar conditions of milling of DR, raw and parboiled milled rice of black variety was the darkest. Raw husk showed higher EMC compared to husk of parboiled. Hardness followed the pattern: Raw: Paddy (~230-280N) > DR (~120-260N) > Milled rice (~110N); for parboiled: DR (~270-480N) > PP (~260-425N) > Parboiled milled rice (~250-340N). Cooking time was high for DR of parboiled ones and least for waxy raw milled rice. Results of this study will be helpful in understanding the quality of pigmented rice cultivars, design and fabrication of some of the equipments in rice processing industry.

Variation of Functional Materials and Antioxidant Activity as Affected by Cultivation Environment in Pigmented Rice Varieties

Production of high quality pigmented rice contained with high content of anthocyanin, and polyphenol was significantly influenced by cultivation environments like transplanting date and cultivation location. This study was carried out to establish an optimum transplanting date and cultivation region to produce maximum content of anthocyanin, polyphenol and antioxidant activity of pigmented rice varieties (black, red colored). Three transplanting times (May 20, June 5, June 20) and four different sites (Miryang, Uiseong, Sangju, Bonghwa) were evaluated with five pigmented rice cultivars. Anthocyanin and total polyphenol index to average temperature during 30 days after heading (DAH) of black, red pigmented rice varieties showed that anthocyanin and total polyphenol contents were decreased by 10% and 9%, respectively, with increasing average temperature of . The optimum ripening temperature of the 30 DAH for the production of high anthocyanin and total polyphenol was 22 to for early maturity black rice, 21 to for mid-late maturity of black and red rices, respectively. On the other hand, an estimated heading date of pigmented rices in return according to the optimum ripening temperature of the 30 DAH was ranged Aug. 11 to 17 for early maturity black rice, Aug. 25 for mid-late maturity black, red rice variety in Jecheon, Aug. 27 to Sep. 2 for early maturity type, Sep. 3 to 6 for mid-late type in Daegu. It seemed that Jecheon, Boeun, Mungyeong, and Yeongju were optimum regions for cultivation of pigmented rices. The estimated sowing date of pigmented rices for high anthocyanin and total polyphenol production based on the optimum heading date was May 18 to 26 for early maturity black rice variety, April 11 for mid-late black, red variety in Jecheon, May 23 to 28 for early type, April 9 to 26 for mid-late type in Boeun, respectively.

Hypolipidemic, hypoglycemic, and antioxidative effects of a new pigmented rice cultivar “Superjami” in high fat-fed mice

Effects of newly-developed pigmented rice Superjami, in comparison with those of its parental cultivars (Heugjinjubyeo and Suweon 425) and ordinary brown rice, on the lipid and glucose metabolisms and antioxidative defense status in high fatfed mice were investigated. The animals were randomly divided and given experimental diets for eight weeks: normal control, high fat, and high fat supplemented with ordinary brown, Heugjinjubyeo, Suweon 425 or Superjami rice powder. Their body weight, plasma lipid profile, blood glucose level, and lipid peroxidation were measured. The enzymes and hormones involved in the lipid and glucose metabolisms were also analyzed. High fat feeding significantly increased the body weight, total cholesterol, triglyceride, blood glucose, and lipid peroxidation in mice. On the other hand, diet supplementation of the rice samples, particularly Superjami, markedly reduced the body weight gain, improved the lipid and glucose profiles, and suppressed oxidative stress through regulation of hepatic lipogenesis and adipokine production, inhibition of glucose-regulating enzymes, and enhancement of antioxidant enzyme activities. Superjami has greater hypolipidemic, hypoglycemic, and antioxidant status-improving effects than its parental cultivars. This study provides the first evidence of the physiological effect of Superjami, which may be useful in the prevention and management of high fat diet-induced hyperlipidemia, hyperglycemia, and oxidative stress.

Physicochemical and nutritional properties of pigmented rice subjected to different degrees of milling

Recent studies have reported the health benefits of pigmented rice cultivars due to the presence of bioactive compounds in the bran layer of caryopsis. This study evaluated the proximate composition, colour, total flavonoids, anthocyanins and proanthocyanidins contents, as well as the total phenolics and antioxidant activity of IAC-600 black rice cultivar and MPB-10 red rice lineage, as a function of degree of milling (DOM), at 0%, 4%, 7%, 10%, 12% and 15% of DOM. Black rice showed a thicker bran layer than red rice. Around 80% and 65% of the ash content of red and black rice, respectively, was distributed in the bran layer. 4% DOM reduced 47% of the fat content in red rice, while in order to reduce similar fat content in black rice, a 7% DOM was necessary. The total free phenolics were around 6- and 7-fold higher than bound phenolics for black and red rice, respectively. Although the non-milled black rice presented higher free and bound phenolics contents than non-milled red rice, the red rice showed higher DPPH and ABTS+ antioxidant activities.

Antioxidant Capacity of Newly Developed Pigmented Rice Cultivars in Korea

ABSTRACTThe antioxidant capacity of newly developed and highly popular pigmented rice cultivars (black rice, Galsaekchalmi, Jeoktomi, Hongchalmi, and Nogwonmi) in South Korea was analyzed. The rice grains were ground into powder, extracted with 70% ethanol, filtered, and concentrated with a rotary evaporator. The samples were analyzed for phenolic, flavonoid, and phytic acid contents, free radical scavenging activity, reducing power, ferrous ion chelating ability, lipid peroxidation inhibition, and superoxide dismutase‐like activity. The ethanolic extracts from pigmented rice cultivars showed greater antioxidant activity than that of the normal white rice. The black rice exhibited the highest free radical scavenging activity, ferrous chelating ability, and total phenolic and flavonoid contents. The reducing power and phytic acid content were found to be highest in Hongchalmi cultivar. The inhibition of lipid peroxidation was markedly higher in Jeoktomi compared with the other rice samples. The Nogwonmi rice showed the lowest antioxidant activity among the pigmented varieties analyzed. These findings provide valuable information on the antioxidant potential of newly developed pigmented rice varieties and may assist plant breeders in the selection of cultivars for the development of new lines of rice with enhanced functional quality.

Comparative metabolic profiling of pigmented rice (Oryza sativa L.) cultivars reveals primary metabolites are correlated with secondary metabolites

Gas-chromatography coupled with time-of-flight mass spectrometry (GC-TOFMS) was used to analyze the relationships between primary metabolites and phenolic acids in rice (Oryza sativa L.), including six black cultivars and one white cultivar. A total of 52 metabolites were identified, including 45 primary metabolites and seven phenolic acids from rice seeds. The metabolite profiles were subjected to data mining processes, including principal component analysis (PCA), Pearson's correlation analysis, and hierarchical clustering analysis (HCA). PCA could fully distinguish between these cultivars. HCA of these metabolites resulted in clusters derived from common or closely related biochemical pathways. There was a positive relationship between all phenolic and shikimic acids. Projection to latent structure using partial least squares (PLS) was applied to predict the total phenolic content based on primary metabolite profiles from rice grain. The predictive model showed good fit and predictability. The GC-TOFMS-based metabolic profiling approach could be used as an alternative method to predict food quality and identify metabolic links in complex biological systems.

Varietal difference in physicochemical properties of pigmented rice varieties

The physicochemical properties of pigmented (Midorimochi, Jeokjinjubyeo, and Heukmichalbyeo) and non-pigmented (Hwayoungbyeo) rice varieties were investigated. Starch from non-pigmented rice consisted mainly of large polyhedral granules that were more loosely packed than those of the non-pigmented sample. Pigmented rice showed higher linoleic acid content (36–40%) and hydrolysis rate (63–79%) but lower oleic acid content (35–39%), blue value (0.05–0.17), and viscosity values than the non-pigmented one. Significantly higher mineral content, blue value, and pasting and viscosity values were observed in the Jeokjinjubyeo sample compared to those of the other pigmented rice samples. The Midorimochi variety, on the other hand, exhibited the highest total amino acid (816.82 ng mg−1) and sugar (0.15–3.35 μg g−1) contents and the lowest pasting and viscosity values. No substantial difference in the X-ray diffraction pattern was observed among the samples. Results of this study could serve as baseline information for the quality evaluation of three pigmented rice cultivars and provide a better understanding of their potential uses and food industry applications.

Variation and Correlation Analysis of Flavonoids and Carotenoids in Korean Pigmented Rice (Oryza sativa L.) Cultivars

Flavonoids and carotenoids of pigmented rice ( Oryza sativa L.), including five black cultivars and two red cultivars, from Korea were characterized to determine the diversity among the phytochemicals and to analyze the relationships among their contents. Black cultivars were higher in flavonoids and carotenoids than the red and white cultivars. The profiles of eight phytochemicals identified from the rice grains were subjected to principal component analysis (PCA) to evaluate the differences among cultivars. PCA could fully distinguish between these cultivars. The Heugjinjubyeo (BR-1) and Heugseolbyeo (BR-2) cultivars were separated from the others based on flavonoid and carotenoid concentrations. Flavonoid contents had a positive correlation with carotenoid contents among all rice grains. The BR-1 and BR-2 cultivars appear to be good candidates for future breeding programs because they have simultaneously high flavonoid and carotenoid contents.

Bran extracts from pigmented rice seeds inhibit tumor promotion in lymphoblastoid B cells by phorbol ester

Using flow cytometry, we quantitatively evaluated anti-tumor-promoting activity of rice bran extracts by measuring inhibition of Epstein-Barr virus early-antigen activation (EBV-EA) induced by the tumor promoter 12- O-tetradecanoylphorbol-13-acetate (TPA). This assay measures anti-tumor-promoting activity and cytotoxicity of target substances using the same batch of cells. Using this short-term procedure, we have determined the anti-tumor-promoting activity of 70% ethanol–water extracts of bran (outer layer) from seeds of five pigmented rice cultivars: Jumlalocal-1, DZ 78, Elwee, LK1-3-6-12-1-1, and LK1A-2-12-1-1. The results show that, compared to an extract from the non-pigmented white cooking rice variety Chuchung, the extracts from the pigmented varieties strongly inhibited phorbol ester-induced tumor promotion in marmoset lymphoblastoid cells B95-8 in vitro. These findings may facilitate development and use of new health-promoting rice varieties.

Antioxidative activities of bran extracts from twenty one pigmented rice cultivars

Ethanol–water (70:30, v/v) extracts from the bran of rice seeds from twenty one pigmented and one nonpigmented rice cultivars were evaluated for antioxidative activities using the following tests: inhibition of peroxidation of linoleic acid; inhibition of peroxidation of rabbit lipid erythrocyte membranes; reduction of potassium ferricyanide, and scavenging of superoxide anions and hydroxyl radicals. With some exceptions, extracts from the pigmented rice seeds had higher antioxidative activity than did the nonpigmented variety. The following pigmented cultivars had the highest antioxidative activities in all tests: Jumlalocal-1, Parnkhari 203, DZ78, LK1-3-6-12-1-1, and Elwee. A significant correlation was also noted between reducing power, inhibition of erythrocyte ghost membrane peroxidation, and superoxide anion and hydroxyl radical scavenging. The results suggest that: (a) ferricyanide reducing power might be a useful and simple index for large-scale evaluation of antioxidative potencies of natural products present in rice; (b) pigmented rice varieties with high antioxidative activities provide a source of antioxidants and a genetic resource to develop new health-promoting rice cultivars.

Differential sensitivity of rice pathogens to growth inhibition by flavonoids

Differential sensitivity of the major pathogens of rice, Xanthomonas oryzae pv. oryzae, Pyricularia oryzae and Rhizoctonia solani to inhibition by certain flavonoids was tested using paper disc/liquid culture and spore germination assays. Naringenin, the first intermediate of the flavonoid pathway, displayed growth inhibition of Xanthomonas strains and spore germination of P. oryzae. On the other hand, no such inhibition was found with Rhizoctonia solani. Crude extracts of leaf and pericarp tissues of a fully purple pigmented rice cultivar, Purpleputtu, also showed growth inhibition of Xanthomonas.

A descriptive study of farming practices for dry seeded rainfed lowland rice in India, Indonesia, and Myanmar

Farmers' traditional dry seeded rice systems were examined: practices were matched to field environments and included ways to address not only weeds, but also poor soil physical properties, water deficit and excess, and poor plant stand. Among others, farmers used pigmented rice cultivars to be able to rogue wild rice and rotated or switched from dry seeded to transplanted rice because of weeds or a too rapid onset of rains. Redistribution of seedlings and manual weeding were used to improve plant stand and soil physical properties in addition to reducing weeds. Farmers' dry-seeding systems did not necessarily reduce labor, but could increase cropping intensity, result in stable yields using low material inputs, or distribute labor demands where some fields are dry seeded and others transplanted. Because of difficult and uncertain environmental conditions, research on direct seeding must build upon farmer practices and knowledge.