• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.406-412
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• 2014

The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

• Research in Plant Disease
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• v.10 no.1
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• pp.73-77
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• 2004

The gene analysis of resistance in rice cultivars, Daeanbyeo, Hwasunchalbyeo, Daejinbyeo, Naepungbyeo, Hwajinbyeo and Surabyeo to strains of Xanthomonas oryzae pv. oryzae was studied. F$_1$ plants and F$_2$ populations from the crosses between six cultivars and near isogenic lines carrying the single bacterial blight(BB) resistance gene were analyzed using Korean and Japanese BB races. Daeanbyeo, Hwasunchalbyeo, Daejinbyeo, Naepungbyeo, Hwajinbyeo and Surabyeo are alleic with IRBB101 but are non-alleic with IRBB104 and IRBB105. The allelic tests indicated that Daeanbyeo, Hwasunchalbyeo, Daejinbyeo, Naepungbyeo, Hwajinbyeo and Surabyeo have the Xal gene for resistance.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.415-423
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• 2018

Rice panicle architecture is an important factor affecting yield potential. Korean rice cultivars have a narrow genetic background for panicle architecture. To enhance the yield potential of Korean rice cultivars, we developed and characterized rice lines with new panicle architecture. Rice with improved panicle architecture has clustered spikelets and dense panicles (CD type). CD rice was derived from a cross between "Binhae Col.#1" carrying dense panicles, and "ARC10319" that has the clustered spikelets gene (Cl). CD rice lines had short and semi-erect panicles with two to five high density spikelets clustered at the tips of primary and secondary rachis branches. CD rice lines had dramatically increased numbers of spikelets; almost twice as many as those of Korean rice cultivars. The increase in spikelet number was mainly caused by the increased spikelets and branches on secondary rachises compared to those on primary rachises. The increase in spikelet number was expected to enhance the yield of CD rice by expanding sink capacity. However, the yield of selected lines; CD9, CD27, CD34, and CD39, did not reach the level of the Korean high-yielding cultivars "Boramchan" and "Hanareum2," due to the reduction in panicle number and grain weight, and poor ripening. Although no substantial yield increase was observed in CD rice, the panicle architecture of CD rice, clustered spikelets, and dense panicles could be new genetic resources as breeding material for diversifying panicle architecture and enhancing yield potential.

• Food Science and Preservation
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• v.20 no.6
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• pp.834-839
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• 2013

The extraction yield, total phenolics content, antioxidant activity, cancer cell growth inhibition (A549 and MCF 7), and lung cancer cell (A549) viability of red rice and black rice were investigated, to evaluate the functional properties of colored rice. The extraction yields and the total phenolics contents of the rice cultivars were Heugseol > Heugkwang > Hongjinju > Jeogjinju > Ilpum. Also, the DPPH radical scavenging activity of the black rice did not differ from that of the red rice, whereas its activity among its cultivars was Jeogjinju > Heugseol > Heugkwang > Hongjinju > Ilpum. The ABTS antioxidant activity of the black rice (Heugkwang, Heugseol) was greater than that of the red rice. The total phenolics was partly attributed to its high antioxidant. On the other hand, the effect of the red rice on the lung cancer cell (A549) viability was higher than that of the black rice. The breast cancer cell (MCF 7) growth inhibition activity of the black rice did not differ from that of the red rice. Our results indicate that the ABTS antioxidant activity of black rice is better than that of red rice, and the lung cancer cell (A549) viability of red rice is better than that of black rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.815-819
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• 2008

The colored rice, particularly black rice, has been well characterized to possess antioxidant properties. Rice bran, a by-product of the rice milling process, contains high levels of several phytochemicals which have antioxidant activities as well as health-beneficial properties. The purposes of this study were to evaluate the antioxidant compounds and antioxidant activities of the methanolic extracts from milling fractions and whole grain of two black rice cultivars. Whole black rice of the two cultivars were milled into rice bran and endosperm using the gradual milling system. These were evaluated for antioxidative activities by DPPH and ABTS radical scavenging activities. To determine the antioxidant compounds in the methanolic extract from the milling fractions, the content of polyphenolics, flavonoids, anthocycanins and ${\gamma}$-oryzanol were measured by spectrophotometric methods and vitamin E analysis was carried out by HPLC. The yield of whole black rice, rice bran, and endosperm were 3.1, 15.3, and 0.9% for Heugjinjubyeo and 2.7, 15.5, and 1.1% for Heugkwangbyeo, respectively. The methanolic extracts from rice bran showed generally higher antioxidant activities than the extracts from whole grain and endosperm. In addition, antioxidant compounds distributed much higher contents in rice bran extract than in the extracts from whole grain and endosperm. A significant correlation was also noted between free radical scavenging activity and polyphenolic compounds. The results of this study show that notable antioxidant activity in black rice bran are considered to have significant health benefits.

• Mycobiology
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• v.29 no.2
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• pp.85-89
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• 2001

URP primers of 20 mer derived from repetitive sequence of rice were used to assess genetic variation of oyster mushroom consisting of 10 cultivars of Pleurotus ostreatus, two cultivars of P. florida and two cultivars of P. sajor-caju which were registered in Korea. URP2F and URP38F primers produced cultivar-specific PCR polymorphic bands in the Pleurotus species. UPGMA cluster analysis using the URP-PCR data showed that 14 Pleurotus cultivars are genetically clustered into large three groups. The URP-PCR data provided important information for more efficient breeding strategies of Pleurotus cultivars.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.283-291
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• 2017

Rice that the half of population in the world eats as a staple food is mostly produced and consumed in Asia. However, its consumption is nowadays decreasing mainly due to diet diversity. Accordingly, some attempts are in demand to enhance the utilization of rice. In this study, profiling of volatile and non-volatile flavor components in rice pastes obtained by ${\alpha}$-amylase was performed and compared according to nine different rice cultivars domestically cultivated in Korea using gas chromatography-mass spectrometry combined by solid phase microextraction and gas chromatography-time of flight-mass spectrometry after a derivatization, respectively. In total, 46 volatile compounds identified included 6 alcohols, 6 aldehydes, 4 esters, 4 furan derivatives, 4 ketones, 1 acid, 1 sulfur-containing compound, 7 hydrocarbons, 5 aromatics and 8 terpenes. The non-volatile flavor components found were composed of 12 amino acids, 6 sugars and 4 sugar alcohols. In principal component analysis, rice paste samples could be discriminated according to cultivars on the score plots of volatile and non-volatile flavor compounds. In particular, some volatile compounds such as pentanal and 4,7-dimethylundecane could contribute to distinguish Senong 17 white and Senong 17 brown, whereas ethanol, 6-methylhep-5-en-2-one, and tridecane could be highly related to the discrimination of Iipum from other cultivars. Among non-volatile compounds, some amino acids such as glycine, serine and ${\gamma}$-aminobutyric acid and some sugars such as sucrose and fructose were mainly responsible for the discrimination of Danmi from the other cultivars. On the other hand, galactose, arabitol and mannose were more closely related to Senong 17 white than Senong 17 brown.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.531-540
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• 2016

Purpose: To improve the cooking quality of brown rice, newly inbred soft rice cultivars were investigated. Methods: The physicochemical properties of brown rice flour and water absorption patterns and cooking characteristics of brown rice grain were compared to Ilmi white and brown rice. Results: General composition and total dietary fiber contents of five rices were significantly different with higher ash, protein, and total dietary fiber contents in soft brown rice than white rice. The hardness of raw rice grain was higher in Ilmi brown rice than in soft brown rice. The water absorption increased rapidly in 30 min of white rice and in 4-6 h of brown rices. The apparent amylose content of soft brown rice was lower than that of Ilmi rice. The initial pasting temperature and all viscosities were significantly different, but the trend was not similar. The textural properties of hardness and roughness were higher, but adhesiveness, cohesiveness, and stickiness were lower in Ilmi brown rice than white and soft brown rices. In sensory preference test, not only textural properties, hardness, adhesiveness, cohesiveness, stickiness, and roughness, but also color, glossiness, and roasted flavor were higher in soft brown rices. Especially soft brown rice B showed the best cooking quality among all rices. Conclusion: The results of the study suggested that soft brown rice is developed for cooking with high nutritional and functional quality.

• Food Science and Preservation
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• v.24 no.4
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• pp.491-496
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• 2017

Paddy rice is typically stored during postharvest until rice grain is processed into brown rice and milled rice by hulling and milling procedure, respectively. Recently, instead of storing paddy rice, storage of brown rice has been in the spotlight because it is more convenient and economically feasible. Different brown rice cultivars with varying amylose contents including waxy rice, medium-waxy rice, and non-glutinous rice were stored in room temperature storage for four months, and the changes in grain qualities of brown rice were evaluated. Amylose content significantly affected pasting properties in which rice cultivar with higher amylose content showed longer pasting time and higher peak viscosity. Storage also affected pasting viscosities, showing an increase in peak viscosity, but a decrease in breakdown viscosity. The changes in pasting viscosity during storage could be an important starch property for aged brown rice utilization. Waxy brown rice showed the weakest aging property in terms of free fatty acids (FFA) accumulation, whereas non-glutinous rice was more substantial grain quality against aging. The FFA values of two months storage were not significantly different from the initial FFA contents, suggesting that brown rice stored in room temperature for two months could be feasible for direct consumption of brown rice.

• 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.