• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.126-131
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• 1984

Twenty one fungi were detected from 26 rice seed samples obtained from Yeongnam Crop Experiment Station, Honam Crop Experiment Station, Chungnam Provincial Office of Rural Development and farmers of Chungnam Province. Gerlachia oryzae was one of frequently detected fungi with $1.0\~45.0\%$ of detection ratio from 22 rice seed samples. The deep-freezing method was selected as the most suitable for routine seed health testing when the blotter method, deep-freezing method and agar plate method were evaluated for efficiency of detecting seed-borne G. oryzae from rice seeds. Our data obtained by seed component plating technique suggested that G. oryzae was present not only on chaff, in endosperm and in seed coat, but also in the embryo. Seed-borne G. oryzae caused seed rot, seedling blight and symptom of brownish discoloration on coleoptile primary and 2nd leaf when the infected seeds were sown in agar of test tube or in soil.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.92-100
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• 2009

To investigate the mutagenecity of sodium azide (SA) and to select mutants having various agronomic characteristics in rice (Oryza sativa L. ssp. japonica), dry seeds of rice variety 'Suweon 472' were treated with 0, 0.5, 1.0, 2.0, and 4.0 mM SA solutions prepared in 0.1 M phosphate buffer (pH 3.0). Germination rate, seedling height and sterility were investigated in $M_1$ generation and chlorophyll mutations were observed in $M_3$ generation. Germination rate and seedling height decreased as the increase of SA concentration in $M_1$ generation, the maximum seed sterility (40.8%) was found at 4.0 mM SA concentration. Chlorophyll mutants were occurred in $M_3$ generation and the frequency calculated on a line basis was 13.5% at the same treatment. Many kinds of mutations for morphological and agronomic characters were observed and mutations with short culm and glabrous leaf were frequently found in $M_3$ generation. Interestingly, five mutant lines resistant to blast or bacterial blight (BB) were selected and evaluated with several isolates in $M_3$ generation although Suweon 472 has been known to be susceptible to blast and BB. These mutants showed all resistance to seven isolates of blast and a total of 76 lines among 2,567 lines evaluated showed resistant to race K1 of bacterial blight. Two mutant lines (440172 and 41272) showed different reaction to BB isolates from the other resistant mutants. A few kinds of endosperm mutants were also identified and most of them were waxy mutants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.219-219
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• 2022

Granule-bound starch synthase I (GBSSI), encoded by the waxy gene, is responsible for the accumulation of amylose during the development of starch granules in rice endosperm. Despite many findings on waxy alleles, the genetic diversity and evolutionary studies are still not fully explored regarding their functional effects. Comprehensive evolutionary analyses were performed to investigate the genetic variations and relatedness of the GBSSI gene in 374 rice accessions composed of 54 wild accessions and 320 bred cultivars (temperate japonica, tropical japonica, indica, aus, aromatic, and admixture). GBSS1 coding regions were analyzed from a VCF file retrieved from whole-genome resequencing data, and eight haplotypes were identified in the GBSSI coding region of 320 bred cultivars. The genetic diversity indices revealed the most negative Tajima's D value in the tropical-japonica, followed by the aus and temperate-japonica, while Tajima's D values in indica were positive, indicating balancing selection. Diversity reduction was noticed in temperate japonica (0.0003) compared to the highest one (wild, 0.0044), illustrating their higher genetic differentiation by F_ST-value (0.604). The most positive Tajima's D value was observed in indica (0.5224), indicating the GBSSI gene domestication signature under balancing selection. In contrast, the lowest and negative Tajima's D value was found in tropical japonica (-0.5291), which might have experienced a positive selection and purified due to the excess of rare alleles. Overall, our study offers insights into haplotype diversity and evolutionary fingerprints of GBSSI. It ako provides genomic information to increase the starch content of cooked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.57-63
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• 2011

Changes in food preferences and dietary habits of Korean prone to decrease consumption of the traditional energy source, rice. The exceeding condition of rice production in Korea is now not only impacting on the profit structure of farmers but also threatening food security. Although there have been several efforts to increase rice consumption rate, by developing various processed foods using rice flour, grain hardness of rice has been the most significant limiting factor. In this study, we addressed the suitability of the Namil(SA)-flo1, a mutant rice line has floury endosperm, in terms of producing rice flour by using dry-milling method, which is lower cost and more eco-friendly than other available methods such as wet-milling. Rice flour of the Namil(SA)-flo1 exhibited superior physico-chemical characteristics to any other check varieties including the wild type, Namil, in terms of distribution of granule sizes and content of damaged starch.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.524-528
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• 2006

This study was performed to develop experimental model for milling degree and whiteness from analysis the CBB (colored bran balance) index using NMG dying and image processing. The endosperm layer increased and the pericarp, aleurone layer and CBB index decreased as the milling degree and whiteness increased. So, CBB index was closely linked to milling degree and whiteness. A empirical CBB index model was developed according to the milling degree and whiteness. The model were found to fit adequately to all test data with a coefficient of determination of 0.99, and therefore the CBB model proved to be quite applicable.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.39-74
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• 2001

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s∼1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great, progress and success was obtained in development of high-quality japonica cultivars and qualify evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice caltivars and special rices adaptable for food processing such as large kernel, chalky endosperm aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and torture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak. hot paste and consistency viscosities of viscogram with year difference. The high-quality rice variety “Ilpumbyeo” showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic mcroscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high Probability of determination. The ${\alpha}$ -amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, shelved the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogiadation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice bread. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large gram rices showed better suitability for fermentation and brewing. Our breeding efforts on rice quality improvement for the future should focus on enhancement of palatability of cooked rice and marketing qualify as well as the diversification in morphological and physicochemical characteristics of rice grain for various value-added rice food processings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.196-202
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• 2013

This study was conducted to evaluate the performances of rice transgenic lines along with their wild types in terms of agronomic traits. A total of 32 rice transgenic lines, through previously conducted collaborative researches between molecular biologists and conventional rice breeders, were selected as promising lines. As the introduced functional genes, 17 genes, which were putatively related with high yield, disease and herbicide resistance, abiotic stress tolerance, and diversifying endosperm starch components, were transformed into three Japonica cultivars, Nipponbare, Nagdongbyeo, and Dongjinbyeo. The transgenic lines exhibited significantly deviated performances from their wild types on agronomic traits such as days to heading, culm length and yield potential. Multivariate analyses on transgenic lines to the evaluated agronomic traits also indicated random manner of phenotypic deviations from their wild type in terms of deviation directions and degrees. Our results suggested that, therefore, breeding strategies to control unexpected deleterious phenotypic performances among transgenic lines would be critical as much as the functions and proper expressions of the transformed genes.

• Journal of the Korean Society of Food Culture
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• v.15 no.4
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• pp.253-258
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• 2000

The chemical components of Korean rice germ were analyzed. Proximate compositions of rice germ were as follows; crude lipid 21.18%, crude protein 16.50%, crude fiber 2.95%, crude ash 6.23% and carbohydrate 44.45%. Free sugar compositions were as follows; fructose 50.20mg/100g, glucose 68.80mg/100g, maltose 569.00mg/100g. Major amino acids of rice germ are glutamic acid (1920.9mg/100g), arginine (1503.7mg/100g), aspartic acid(1208.7mg/100g) and leucine (1039.7mg/100g). Fatty acid compositions of rice germ lipid extracted by chloroform-methanol (2:1) were palmitic (22.2%), linoleic acid (38.9%), oleic acid (24.7%) and palmitic acid (22.2%). Mineral elements were phosphorus (1766.22mg/100g) and potassium (1217.80mg/100g). Vitamins were composed of Vit E (11.96mg/100g) Vit B1 (5.69mg/100g) and niacin (2.96mg/100g). 16 flavonoids and 9 phenolic acids in rice germ were not detected. Above the chemical components of rice germ were compared with that of rice endosperm and wheat germ.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.644-651
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• 2009

This study was conducted to investigate the effects of steeping periods and temperatures of waxy rice on the microflora and enzyme activities of steeping water and waxy rice, as well as on the microscopic structures of waxy rice during the preparation of gangjung. When the steeping water was 15 and $35^{\circ}C$, yeast and lactic acid bacteria were the major microflora after 1 day. After 11 days, Lactobacillus spp. were the major bacteria, while Bacillus spp. were the primary microflora after 21 days. At $25^{\circ}C$ the primary species were Bacillus spp., Leuconostoc spp., and Bacillus spp. after 1, 11 and 21 days, respectively. The $\alpha$-amylase activity of steeping water increased proportionally with the increase of temperature and period, while the protease activity tended to increase for 11 days, but decreased at 21 days. The enzyme activities of the steeped waxy rice, especially the $\alpha$-amylase activity, decreased with higher steeping temperature, while the $\beta$-amylase and glucoamylase activity remained constant for up to 21 days. Observation using scanning electron microscopy indicated that intracellular cleavage of steeped waxy rice endosperm resulted in a rough surface morphology due to the exposure of polygonal starch granules. Tiny pinholes on the surface of waxy rice starch granules were also observed after steeping for 11 days.

• Journal of Nutrition and Health
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• v.53 no.2
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• pp.99-110
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• 2020

Purpose: The rice germ fraction is a better source of protein, lipid, and fiber than the rice endosperm. Furthermore, the rice germ is rich in bioactive phytochemicals such as γ-aminobutyric acid, tocopherols, tocotrienols, phytic acid, and so on. In this study, the phytosterol content and antioxidant activity of Keunnunjami germ (KG) or normal rice germ supplement were investigated in healthy adult rats. Methods: In vitro, quantitative assessment of phytosterols, including β-sitosterol, campesterol, cycloartenol, and stigmasterol, was performed. Comparative antioxidant activities of 2 rice germs were measured based on DPPH radical scavenging activity, reducing power, and ABTS radical scavenging capacity. In vivo, male Spraque-Dawley rats (30-weeks-old) were randomly assigned a diet of normal control (NC, AIN-93M diet), AIN-93M diet supplemented with normal rice germ 3% (NG3), or AIN-93M diet supplemented with KG 3% (KG3) and fed for 8 weeks. Results: KG contained significantly higher campesterol and stigmasterol contents and antioxidant activity than normal rice germ. The KG3 group exhibited significantly lower body weight gain as well as inguinal and total white adipose tissue weights. There were no significant differences in plasma glucose, insulin, C-peptide, or homeostasis model assessment of insulin resistance level among the 3 groups. The plasma tumor necrosis factor-α concentration was significantly lower while leptin, advanced oxidation protein products, and interleukin-6 showed downward trends in the KG3 group. In addition, the superoxide dismutase level of the KG3 group was significantly higher compared to the NC and NG3 groups. Conclusion: This study indicates that KG can be considered as a valuable source of phytosterol components. Lastly, KG has strong antioxidant properties and may have potential to ameliorate elevation of proinflammatory cytokine production with age.