• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.951-958
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• 2003

Twenty-four cultivars of colored rice seeds were collected inside and outside Korea, and the antioxidant and antimutagenic activity was determined for the solvent-fractionated layers of their bran parts lipid soluble fraction, pigment containing fraction, and pigment component per se. As the serial organic solvent extraction proceeded, the overall tendency of antioxidant activities declined with increased chemical homogeneity of each fraction. This markedly showed the low antioxidativities of the pigment components from LK 1-3-6-12-1-1 and Gillimhukmi. Even all the colored rice cultivars, with considerable antimutagenic activity in 70% ethanolic extract, exhibited mutagenicity when measured with its pigment containing fraction (wx 124-163-45-7-1-1-1 and LKlB-2-1-1 being the strongest). The pigment content in each colored rice seeds decreased in the order of IR 17491-5-4-3-3>LK 1-3-6-12-1-1>LK 1D-2-12-1>RGS No.336, Elwee. In addition, a substantial difference in both chemical composition of the constituents and its amount could be found between the colored rice and cooking rice cultivars. This revealed that, compared to cooking rice, major components of organic solvent fractions from colored rice probably have long hydrocarbon chain moieties.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.5
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• pp.830-841
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• 2015

This study compared the physicochemical characteristics, proximate composition, taste compound and antioxidant properties of Sikhye prepared with pigmented rice. Proximate composition showed a significant difference depending on the type of pigmented rice except crude fat contents and pH, color was a significant difference depending on the type of pigmented rice. The highest brix degree was $15.07^{\circ}Brix$ in red and black rice Sikhye. Each highest value of reducing sugar and free sugar content showed milled rice and brown rice Sikhye. Titratable acidity and total acidity of the pigmented rice Sikhye were highest for black rice Sikhye, free sugar content were highest for green rice Sikhye. Analysis of their relative antioxidative properties indicated that black rice Sikhye had the highest total polyphenol, flavonoid, and anthocyanin content, the highest levels of DPPH radical scavenging ability, and the highest level of reducing power and ferric reducing ability of plasma scores. Principal component analysis suggested that black rice Sikhye had a strong association with antioxidant properties, brown and red rice Sikhye had the strongest association with the sweetness and unique flavor.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.624-630
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• 2004

Functionality changes by germination of giant embryonic rice and pigmented rice were evaluated with focusing on antioxidative activities of 70% ethanolic extracts. Overall, reducing power of giant embryonic rice and pigmented rice was higher than that of normal brown rice, and the germination of rices tend to enhance their reducing powers. In vitro and ex vivo experiments employing linoleic acid peroxidation and rabbit erythrocyte membrane peroxidation systems, respectively, revealed inhibitory effect on lipid peroxidation was highest in pigmented rice, followed by giant embryonic rice, and normal brown rice from high to low order. Superoxide radical-scavenging activity decreased in order of pigmented rice > giant embryonic rice > normal brown rice, and germination also enhanced their superoxide scavenging ability compared to non-germinated controls. Hydroxyl radical-scavenging ability was highest in pigmented rice, followed by giant embryonic rice, and normal brown rice. Despite marked enhancement in hydroxyl radical-scavenging ability of normal brown rice by germination, order of scavenging ability was not altered among germinated rices. Same trend as with in vitro ROS scavenging was observed for ex vivo scavenging potency on ROSs generated by TPA stimulation in HL-60 cells. Germination-associated differential increase in ROS scavenging ability of pigmented rice and giant embryonic rice, characterized by no induction of cytotoxicity, was observed.

• Proceedings of the Korean Nutrition Society Conference
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• 2001.05a
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• pp.236.2-236
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• 2001

• Applied Biological Chemistry
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• v.48 no.3
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• pp.233-239
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• 2005

Lipid-soluble fractions extracted with methylene chloride and ethyl acetate as well as 70% ethanolic extract were made from 5 cultivars of the pigmented rice brans (DZ 78, Elwee, LK1A-2-12-1-1, LK1-3-6-12-1-1 and Killimhukmi) to determine their antioxidative activities and to measure the contents of phenolic compounds, phytic acid, together with unsaponificated compounds such as retinol, tocopherol and stigmasterol. We also attempted to characterize candidate components in charge of antioxidation and measure their relative contents in each methylene chloride and ethyl acetate fraction by using GC-MS techniques. As the results, we found a 30% higher antioxidative activity with 26-fold greater phenolic compound content of the pigmented rices as compared to those of the normal rice. Especially, in Killimhukmi, the contents of the unsaponificated compounds such as retinol, tocopherol and stigmasterol were also found to be more than 2.3-fold greater than those of normal rice. However, we could not find the overall correlations between antioxidativity of rices and their color values, or unsaponificated compounds contents. Methylene chloride fraction from Killimhukmi and LK1A-2-12-1-1, both showing strong antioxidativity, contained relatively high contents of (Z)-9-hexadecenyl ester-9-octadecanoic acid and 2-Hydroxyl-1-1(hydroxymethyl) ethyl-9-octadecanoic acid, respectively. In ethyl acetate fractions, on the contrary, 1H indene, methyl ester-tetradecanoic acid and methyl ester-hexadecanoic acid were detected as the commonly-occurring substances in the 5 cultivars of pigmented rices, implying a possible role in antioxidative action.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.17-24
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• 2012

The present study was performed to expand the application of mechanically impacting technology reported in our previous studies. Several parameters were analyzed to research Korean indigenous pigmented rice. The proximate composition of Korean indigenous rice was the following; 12.0-13.4% moisture, 74.1-77.3% carbohydrate, 6.8-8.7% crude protein, 1.68-3.25% crude lipid, 0.78-1.38% crude ash, with a 6.6-7.07 pH value. The phenolic compound content of red rice was twice that of black rice. Moreover, antioxidative activity was estimated by DPPH radical-scavenging activity (IC50 = 0.15-1.04 mg/mL). Anthocyanin and chlorophyll in each pigmented rice type were detected by spectrophotometer. Garaedduk samples were prepared with non-waxy rice, salt, 24% water, and/or 15% indigenous pigmented rice(red, green and black, w/w of total swelling non-waxy rice) and adapted with or without mechanically impacting technology. Hardness, as a main texture profile parameter of Garaedduk was maintained up to 3 days under storage at $20^{\circ}C$. The results suggest that Korean indigenous pigmented rice can be applied for functional Garaedduk adapted with mechanically impacting technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.153-162
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• 2016

We investigated the physicochemical properties and starch structure of various rice varieties including 15 colored cultivars. NKHC showed the highest level of protein, lipid, and total dietary fiber levels. Reddish brown rice showed higher lipid content than that in black rice cultivars. Apparent amylose content of waxy and non-waxy colored rice varieties was within the range of 3~5% and 15~18%, respectively. IP exhibited the highest total starch (TS) content, whereas, NKHC and HJJ showed lower TS content than that in other cultivars. Pasting temperature of all colored rice cultivars, except IP, was about $68^{\circ}C$. Peak viscosity of IP, JJJ, Hong, and GGHM showed high values of 138, 130, 128, and 124, respectively. All the colored rice cultivars presented A-type X-ray diffraction pattern and polygonal shapes of starch granules were observed using scanning electron micrographs (SEM). Major groups of amylopectin chain lengths were B (12 < DP ${\leq}$ 24) and A (DP ${\leq}$ 12). SMHC showed the highest B chain content and the lowest A chain content (P < 0.05). These experimental results provided useful information for scientists and the food industry regarding colored rice starches.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1405-1409
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• 2010

The compositions of fatty acid and amino acid of specialty rice which includes colored rice (Heugjinju, Jeugjinju, Josangheugchalbyeo), flavored rice (Heughyangmi, Hyangmi1), and giant embryo rice (Keunnun) were determined and compared to those of regular rice (Ilpumbyeo, Whaseonchalbyeo). Major fatty acids were linoleic acid (C18:2) and oleic acid (C18:1), which were composed of 75~80% of total fatty acids. Major amino acids were glutamic acid and aspartic acid in most cultivars but Jeugjinju in which cysteine (169.61 nmol) and GABA (129.32 nmol) were the most abundant amino acids. Thermal properties measured by differential scanning calorimeter (DSC) revealed that the enthalpy (${\Delta}H$) for starch gelatinization was the highest in Josangheugchalbyeo and Whaseonchalbyeo. It suggests that the starch structure of waxy rice could be more crystallized compared to non-waxy rice, and also that amylopectin could have more impact on starch gelatinization than amylose. The on-set and complete temperature for starch gelatinization were higher in colored rice of Heugjinju and Jeugjinju, and regular rice of Whateonchalbyeo.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.581-583
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• 1995

Anthocyanins in Korean pigmented rice(Oryza sativa var. Suwon 415) were analyzed to develop value-added natural pigment from rice. The pigment extracted with 1% HCl in methanol was determined as anthocyanins by characteristic absorption spectra in UV-visible ranges showing maximum absorbance at 280 nm and 530 nm. Two aglycones from acid-hydrolyzed anthocyanins were identified as cyanidin and malvidin by their $R_f$ values in several developing solvents, spectral properties, and $^1H-NMR$ analysis. Sugar moiety was determined as monoglucose by paper chromatography. The main anthocyanins in Korean pigmented rice were tentatively identified as cyanidin-3-glucoside and malvidin-3-glucoside.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.222-227
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• 2005

To evaluate the antimutagenic activity of the specialty rices, a giant embryonic rice and a pigmented rice, we measured the inhibitory effect on the chemically induced mutagenesis in E. coli and V79 cultured cell system, as well as on DNA strand scission induced by oxidative damages in vitro. When the inhibitory activity to mitomycin C-induced mutagenesis using SOS chromotest in E. coli cell was measured, the activities decreased in the following order: germinated pigmented rice (40.4%) > germinated giant embryonic rice (37.1%) > pigmented rice (35.5%) > germinated brown rice (15.7%) > giant embryonic rice (14.0%) > brown rice (0.8%). The activities for inhibiting mitomycin C-induced DNA strand scission decreased in the order of pigmented rice > giant embryonic rice > germinated pigmented rice > germinated brown rice > brown rice > germinated giant embryonic rice. We also determined antimutagenic activities of the specialty rices using the suppressing effect on 6-TG resistant colony formation by 4-NQO in V79 cells as a mutagenicity index. The order of antimutagenicity was germinated giant embryonic rice (53.2%) > pigmented rice (40.0%) > brown rice (21.2%) > germinated brown rice (14.4%) > giant embryonic rice (0.23%); in contrast, germinated pigmented rice showed promoting effect on 4-NQO-induced mutagenesis.