• Korean Journal of Plant Resources
• /
• v.30 no.3
• /
• pp.318-322
• /
• 2017

The study was carried out to determine the changes of growth characteristics, anthocyanidin, and brown rice yield grown at coast and inland areas apart from the east coastline of Gyeongsangbuk-do province. Number of spikelets per panicle was much more increased in inland area. Regional difference in number of spikelets per panicle was observed in Jeongjinju cultivar. Among these red rice cultivars, the highest brown rice yield was Jeongjinju rice cultivar having 702 kg in inland area and 692 ㎏ in coast area, respectively. Anthocyanidin content ranged 524 to $610{\mu}g/g$ dry weight basis. Cyanidin content was 11.4 to 14.0 times higher than that of delphinidin under coast and inland area. Anthocyanidin content was higher in rice cultivar grown at coast area. Highest head brown rice rate was only observed in Geonganghongmi to 95.2 at coast area and 95.4 inland area. In considering brown rice yield and pigment content, Hongjinju rice cultivar was recommended in optimal pigment rice cultivar in eastern coast of Gyeongsangbuk-do Province.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.278-278
• /
• 2017

Brown rice grains are increasingly attended by consumers due to their potential health benefits of antioxidant capacity. Therefore, this research was carried out to evaluate the antioxidant activity of brown rice in Korea-native weedy rice germplasm. Two hundred and twenty one accessions of weedy rice used in this study were received from the National Agrobiodiversity Center of RDA, and were regenerated in the experimental field of Chonbuk National University. The sampled seeds were extracted using methanol and the extracts were analyzed using the 1, 1-dipheny-2-picrylhydrasyl (DPPH) free radical scavenging assay for antioxidant capacity determination. Among the all germplasm, the samples of seed coat in red colour, white colour, red -white mixing colour and brown colour were 171 (81%), 26 (12%), 12 (6%) and 2 (1%), respectively. The antioxidant activity values of all samples were varied in the range from 22.31% to 95.53 % and mean value was 82.09%. Depend on the seed coat colour, the average antioxidant activity of the extract of weedy rice seeds indicated that the following order in seed coat colour: red colour (89.11%) > the red-white mixing colour (70.67%) > brown colour (53.16%) > white colour (45.99%). The antioxidant activity of red coloured weedy rice were significantly higher than those of the others. It is suggested that Korea-native weedy rice accessions with high antioxidant activity could be developed as a potential functional food material by further research of component analysis.

• Korean Journal of Agricultural Science
• /
• v.43 no.3
• /
• pp.330-339
• /
• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.5
• /
• pp.1929-1933
• /
• 2012

Oxidative stress has been proposed to be involved in colorectal cancer development. Many dark pigments of plants have potent oxidative stress preventive properties. In this study, unpolished Thai rice was assessed for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. Red strain unpolished Thai rice was also administered to rats exposed to azoxymethane (AOM) for induction of aberrant crypt foci (ACF). Serum malondialdehyde (MDA) and ferric reducing antioxidant power (FRAP) were investigated for cellular oxidative stress and serum antioxidants, respectively. Red pigment unpolished Thai rice demonstrated high antioxidant activity and was found to significantly and dose dependently decrease the total density and crypt multiplicity of ACF. Consumption of Thai rice further resulted in high serum antioxidant activity and low MDA cellular oxidative stress. Interestingly, the density of ACF was strongly related to MDA at r = 0.964, while it was inversely related with FRAP antioxidants (r = -0.915, p < 0.001). The results of this study suggest that the consumption of red strain of unpolished Thai rice may exert potentially beneficial effects on colorectal cancer through decrease in the level of oxidative stress.

• Journal of the Korean Applied Science and Technology
• /
• v.4 no.1
• /
• pp.19-22
• /
• 1987

To investigate the protective action of various antioxidants on the photooxidation of rice bran oil, it was irradiated with red and visible light in presence and absence antioxidants with or without sensitizer (methylene blue). 1. Rice bran oil with and without sensitizer in chloroform-ethanol (4:1, v/v) media was largely oxidized under visible light irradiation. on the other hand, rice bran oil without sensitizer was hardly oxidized under red light irradiation. 2. Rice bran oil with sensitizer was oxidized much faster than that without. And the absorbance of it irradiated with visible was increased more than that with red light. 3. The effectiveness of antioxidants on the rice bran oil photooxidation was same order as follows: Irradiation with visible light, no addition of sensitizer ${\beta}$-carotene > dl-{$\alpha}$-tocopherol > BHT > BHA Irradiation with visible light, addition of sensitizer ${\beta}$-carotene > BHT > dl-${\alpha}$tocopherol > BHA Irradiation with red light, addition of sensitizer ${\beta}$-carotene > BHA > BHT > dl-${\alpha}$-tocopherol From these results, we concluded that rice bran oil was largely oxidized under visible light irradiation, therefore it must be protected from photooxidative deterioration by the addition of antioxidants.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.56-60
• /
• 1997

In order to investigate the relationships between the responses of four crops (rice, soybeans, potatoes, and red pepper) to acid rain, the simulated acid rain(SAR) of pH 1.8, 2.3, and 2.8 and normal rain of pH 6.0 were applied from 30 days after emergence to harvest at the two-week interval for rice, soybeans and red pepper and at a week interval for potatoes. SAR of pH 1.8 and 2.3 caused brown spots in the leaves of rice, soybeans, and red pepper and the damages were severer as the pH of SAR lowered, while no visual damages were observed in potatoes. The SARs did not affect chlorophyll content of rice and potatoes, while chlorophyll content of soybeans and red pepper decreased as the pH of SAR lowered. Photosynthetic activity was not significantly different among the pHs of SAR in rice, while decreased as pHs of SAR lowered from pH 2.8 to 1.8 in soybeans, potatoes, and red pepper. Yield of rice, soybeans, and potatoes was not affected by the pHs of SAR, but in red pepper the length, diameter, and weight of a fruit, the number of fruits per plant, and total matured fruit yield decreased as the pHs of SAR lowered. In rice and potatoes visual damages caused by SAR did not correlated with other observed traits. However, visual damages were negatively correlated with chlorophyll content and photosynthetic activity of soybeans and photosynthetic activity and yield of red pepper.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.4
• /
• pp.499-502
• /
• 2007

The objective of this study was to determine antioxidant compounds in specialty rice including milled rice, brown rice, red rice, giant embryonic rice, black rice, green rice, and Goami consumed in Korea. The concentrations of total polyphenols (insoluble and soluble polyphenols), phytic acid, and anthocyanin in the samples were measured using spectrophotometric methods and vitamin I analysis was carried out by HPLC. The contents of the total polyphenolic compounds were 565mg/100g for black rice, 405mg/100g for red rice, 140mg/100g for giant embryo rice, 138mg/100g for Goami, 133mg/100g for brown rice, 127mg/100g for green rice, and 66mg/100g for white rice. The black and red rices were significantly high in polyphenolic contents compared with the other rices, apparently due to their intense red-purple color. Black rice, red rice, and Goami showed significantly higher vitamin E and phytic acid contents compared with other rices. Anthocyanins were determined in only black rice (302mg/100g) due to the detection limits of spectrophotometric assay. hlthough vitamin I and anthocyanin contents were relatively lower than polyphenolics among the samples, the specialty rice may contribute to the significant supply of antioxidant compounds to prevent oxidative stress due to the fact that rice is used as a staple food and consumed in large amounts in our diets. The results can be used to increase rice consumption by enhancing consumer awareness on health benefits of the rice.

• Korean Journal of Weed Science
• /
• v.3 no.2
• /
• pp.143-150
• /
• 1983

Red rice (local name "Sore") as a weed has been a serious threat to rice production in direct-seeded rice culture in Ganghwagun, Gyeonggi province. In the Ganghwagun 508 ha out of 1,420 ha in the Samsanmyeon area is infested with red rice. The average lowland rice yield is about 4,300 kg/ha in the Ganghwagun, but the average upland rice yield is about 2,000 kg/ha in infested area. This study was carried out in order to clarify the ecological characteristics of red rice and factors affecting the competitive ability of five red rice varieties, collected from Samsanmyeon in 1981, with rice cultivar. Five varieties-Monggeunsare, Salsare, Ginkaragsare, Galsaegsalsare, Galsaegkaragsare-showed the same morphological characteristics of cultivated Japonica type, Chuncheongbyeo, but red rice tillers more profusely, is taller and lodges more easily than Chucheongbyeo. It shatters easily about 10-15 days after heading date, and at this time the hull is discolored in yellow or dark brown. There are many types of red rice with short or long owns on the spikelet, occasionally with or without own on the spikelet in the same hill, and the grains are short or long. In red reice leaf blast occurs more severely than in cultivated Indica/Japonica type, Teabaegbyeo, particulary serious in Monggeunsare. When red rice invaded in direct-seeded rice, number of panicles of rice became reduced more than other yield components.

• Applied Biological Chemistry
• /
• v.25 no.4
• /
• pp.252-256
• /
• 1982

To investigate the influences of biological factors on stored rice and their interactions, the activities of red Hour beetle(Tribolium castaneum) and 2 species of Aspergillus was observed during 6 weeks at $28^{\circ}C{\pm}1^{\circ}C$. It was found that the red flour beetle could complete its life cycle on rice in six weeks. Its activity caused the increse of moisture content of rice(max. 1.3%) after 6 weeks, but the number of mold propagule on the surface of stored rice decreased. The growth of red flour beetle showed a stabilizing tendency on rice inoculated with Asp. repens while it was retarded with Asp. niger.

• The Plant Pathology Journal
• /
• v.17 no.5
• /
• pp.249-256
• /
• 2001

Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.