• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.1-7
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• 2021

The processing of rice is one of the measures to expand the scope of rice use in response to the decrease in rice consumption. Since the main ingredient of rice processing is rice flour, "rice flour varieties" have been bred with the aim to improve the productivity and quality of rice flour. In order to study the variation in the ripening characteristics of rice flour varieties with respect to temperature, the average temperature after heading date was set at 28℃ (33/23℃), 22℃ (27/17℃), and 18℃ (23/13℃) inside the phytotron. We used Saenuri as non-glutinous rice variety, Seolgaeng as soft-type rice flour variety, and Baromi2 as powdered rice flour variety. At high temperatures (28℃), the grain weight of Baromi2 decreased by 21%. Its starch content also decreased by more than 10%, which was significantly lower than that of Saenuri and Seolgaeng. At low temperatures (18℃), the grain weight and starch content slightly increased or were similar in all varieties. An analysis of changes in the grain weight due to effective accumulated temperature through the sigmoid function showed that the velocity of grain-filling slowed significantly when Baromi2 was exposed to low temperature during the ripening stage compared to the other varieties. Therefore, the transplanting time of Baromi2 should be delayed to avoid high temperatures during the ripening stage. However, because the ripening period is not properly secured under low temperature conditions, grain filling may not be sufficient.

• Journal of Life Science
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• v.32 no.9
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• pp.698-705
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• 2022

Rice consumption in Korea is continuously decreasing; therefore, methods for reducing rice stocks are now being proposed. Increasing the consumption of rice and reduce these stocks will require that the rice processing industry be developed beyond simply using cooked rice as food. The Korean people's eating habits have also diversified recently, and the consumption of bread is increasing. Therefore, breeding a cultivar for rice flour is now necessary. Here, a line suitable for processing into rice flour was cultivated by deriving a mutant line by tissue culture of Ilpum. Mutant populations were investigated for major agricultural traits in the field, and grain characteristics and endosperm characteristics were investigated after harvest. Among the lines, line 29111 had similar agricultural characteristics to the background Ilpum, and excellent grain quality, and was selected for further analysis. The physicochemical properties that determine taste were similar or improved. However, unlike Ilpum, 29111 had a non-uniform starch structure and a characteristic powdery endosperm because large and male starch grains are evenly distributed. Therefore, 29111 was viewed as a breeding line suitable for processing and for excellent agricultural characteristics and taste. The added value can be increased by diversifying the uses of rice. The taste was improved and a method for breeding cultivars with grain characteristics for glutinous rice that would satisfy both producers and consumers was presented.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.261-272
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• 2008

This study was conducted to provide the fundamental data based on the agronomic characteristics of domestic aroma rice, widely cultivated domestic rice and foreign aroma rice for breeding of functional aromatic rice. Among the 104 varieties, all of domestic aroma rice and widely cultivated rice varieties were headed, 24 of 84 varieties of foreign aroma rice were not headed. The average heading date of domestic aroma rice Japonica types of domestic rice was later as 136 day, and Tongil types of domestic aroma rice were faster as 122 day. The average culm length of Indica types of foreign aroma rice was longer as 130 cm, and Tongil types of were shorter as 74 cm. The average panicle length of domestic aroma rice and traditional rice were about 21 cm, and Indica types of foreign aroma rice were longer as 29.5 cm. The average 1,000 grain weight of Tongil types of domestic aroma rice and was not a difference with the domestic aroma rice and was more 2.5 g than the Indica types of foreign aroma rice. The average ratio of grain width and length of Indica types of foreign aroma rice were highest as 3.29 (W/L), and the domestic traditional rice was lowest as 1.7 (W/L). The average fertility rate of the domestic aroma rice, the widely cultivated domestic rice, and the Japonica types of foreign aroma rice were above 89.7%, but the Indica types of foreign and the Tongil types of domestic aroma rice were below 65.4%. The average germination rate of foreign aroma rice were above 83.7%, and domestic aroma rice were above 90.4%. The non-glutinous rice were 64 varieties (84.2%) of total 104 accessions of material rice and the waxy rice were 7 varieties (1%). In the domestic aroma rice, Hyangmi2ho and Aranghyangchalbyeo has a mild aroma grade. In the foreign aroma rice, 22 of 40 varieties of Indica types and 9 of 16 varieties of Japonica types has a lightly aroma grade. And 13 varieties of widely cultivated domestic rice has a non-aroma grade.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.15-32
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• 2002

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 quality 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 cultivars 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, Recently, new special rices such as extremely low-amylose dull or opaque non-glutinous endosperm mutants were developed. Also, a high-lysine rice variety was developed for higher nutritional utility. 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 texture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak, hot paste and consistency viscosities of viscosities with year difference. The high-quality rice variety "IIpumbyeo" 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 microscope. 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 IIpumbyeo, Chucheongyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tonsil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation 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 breed. 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 grain rices showed better suitability far fermentation and brewing. The glutinous rice were classified into nine different varietal groups based on various physicochemical and structural characteristics of endosperm. There was some close associations among these grain properties and large varietal difference in suitability to various traditional food processing. Our breeding efforts on improvement of rice quality for high palatability and processing utility or value-adding products in the future should focus on not only continuous enhancement of marketing and eating qualities but also the diversification in morphological, physicochemical and nutritional characteristics of rice grain suitable for processing various value-added rice foods.ice foods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.203-216
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• 2008

This study was conducted to provide the fundamental data based on the analysis of phsyco-chemical characteristics of domestic aroma rice and foreign aroma rice for breeding of aroma rice. The average amylose content of domestic aroma rice and widely cultured domestic traditional rice were 18.1% and 19.0% respectively. The Indica and the Japonica types were 25.6% and 25.0%. In the domestic rice of Tongil and Japonica type, the average protein content were 7.6% and 6.4% respectively. And the average protein content of foreign Indica and Japonica type were 7.6% and 7.0% respectively. And the average protein content of widely cultured domestic traditional rice was 5.6%. The Japonica type of rice shown a low protein content compared with Indica type of rice, and the foreign Indica types of rice exhibited a wide range of protein contents. The average alkali digestive value (ADV) of Tongil type of the domestic aroma rice was about 5.0 and the value of Japonica type was about 6.0. The average ADV of foreign Indica and Japonica type were 4.3 and 5.1 respectively. Also the average ADV of widely cultured domestic aroma rice was about 6.0. The foreign aroma rice were distributed a variable range of ADV value and lower than the both domestic aroma rice and widely cultivated domestic rice. In the whole aspect of the amylogram, the highest viscosity, the lowest viscosity and the last viscosity of the total resources, in domestic aroma rice were clearly lower with the next order, Japonica type of foreign aroma rice, Indica type of foreign aroma rice, Japonica type of domestic aroma rice, widely cultured domestic traditional rice, and Tongil type of domestic aroma rice. It shown the difference aspect of amylograms according to the eco-type of the domestic and foreign aroma and the general rice, and it was distinguishable in difference of the aspect of the amylogram of the endosperm of rice as non-glutinous rice, waxy rice, and middle-waxy rice.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.377-386
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• 2006

Imwonshibyukji(1827) is an important and stupendous ancient scientific book, which is much like an encyclopedia, that can discern the dietary life of the latter period of Choseon. This article is assorted, which is mentioned in this book, as Cho(Misutkaru-in parched grain that is weed out into powder) to the main material of grain Youmicho, Wandoocho, Youcho, also the medicinal plant as the main material Youkhangcho, Backyupcho, Chungumcho, Unyoungcho, and Naecho, Haengcho, Eicho, Imgumcho, Joyou, Bokbunjacho, made by fruit. The results of inquiring the property by the assortment is as you see in the following. Youmicho, Wandoocho, Youcho, Youkhyangcho, Backyupcho, and Chungumcho, which consist of glutinous rice, nonclutinous rice, barley, buckwheat, pea, and black soybean are among 13 kinds of methods to make Cho. The manufacturing process is similar to that of Misutkaru, but in the case of Unyoungcho 6 different medicinal powders are mixed with Chundang and Sookmill to form a hard portable taffy substance, which is quite unique. Naecho, Haengcho, Eicho, Imgumcho, Joyou, and Bokbunjacho are extracted from pulp and processed in a powder form like Misutkaru, which can also be considered as a fruit tea. Youcho is unique in its sense, since it is fermented by maggots that are bred in order to obtain the juice. Cho is known to calm thirst and empty stomachs, and has various medicinal materials to act as food to aid virility. It is also known to have multiple functions as an alternative staple, refreshment to aid virility, portable food, and preferable beverage. There are ten references on Cho, 37% are Korean in Ongheejobji and 63% Chinese in Jaeminyosool, Bonchogangmok, Chungmoonbobang, Nongjungchunsuh, Wangshinongsuh, Shikgyung, Sukmyung, Bonchoseupyou, and Wisaengbogam. The citations are in the general introduction and 13 types of Cho are cited 19 times overall, but citations based on Chinese references are non existe.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.935-942
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• 2009

For the economical use of the medicinal effects and functionality of Chrysanthemum indicum L (gamkug) this study analyzed the physicochemical and sensory characteristics of juak (tradition Korean rice cakes such as backed rice cakes) prepared with different levels of Chrysanthemum indicum L. powder (0, 1, 2, 3, 4, 5%). The diameter of the juak increased with increasing levels of the added gamkug powder, whereas the height decreased with increasing amount of the powder. The Hunter colorimeteric L-values of the dough and gamkug-juak decreased as the amount of gamkug powder increased. Hunter a and b-values both increased with increasing levels of the gamkug powder. Textural characteristics results for the gamkug juak dough indicated increasing hardness and, chewiness values as the amount of gamkug powder increased. After cooking, there were decrease in hardness and chewiness as the amount of gamkug powder increased. Springiness, cohesiveness, brittleness were not significantly different as the level of gamkug powder increased. According to sensory evaluation results, appearance, color, and flavor showed significantlyn (p<0.001) higher scores as the addition level of gamkug powder increased. The 2~4% addition of gamkug powder presented significantly (p<0.001) higher scores for non-oily and herb taste. There were no significant differences in the sensory texture results among all treatments of the juak. After taste was deemed best for the containing 3% gamkug powder. Overall, the optimum addition level of gamkug powder was proposed as 3% in glutinous flour for attributes of appearance, taste, flavor, texture, and the overall acceptability of the product.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.316-323
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• 1996

Flavor components in mash of Takju prepared by different raw materials such as nonglutinous rice, glutinous rice, barley and wheat flour were detected by GC and GC-MS method using non-polar column. Seven alcohols, 15 esters, 10 organic acids, 1 aldehyde, 4 benzenes, 3 phenols, 8 alkans, 2 ketones and 5 others were found in takju after 16 day of fermentation. takju by wheat flour had the most various components of volatile flavor. Treatment with addition starter had less flavor component than that without addition starter in takju by nonglutinous rice. Nine kinds of flavor components including acetic acid ethyl ester, 3- methyl-1-butanol, acetic acid, ethyl benzene, acetic acid 3-methyl butyl ester, 2-phenylethanol, 2,6-di-tert-butyl-4-methyl phenol. plumbagic acid and 1,2-benzenedicarboxylic acid dibutyl ester were commonly detected in all the treatments. Especially, 2,4,0-trimethyl-1,3-benzenediamine was isolated in takju that was made of nonglutinous rice without addition starter. Diethyl sulfide, 4-methoxy benzaldehyde, docosane and 2-methyl propyl octadecanoic acid were isolated from takju by nonglutinous rice with addition starter. Propionic acid ethyl ester, acetic acid butyl ester, 2-methyl butane and 3-methyl pentane were isolated from takju glutinous rice. 2-Hydroxy-4-methyl pentanoic acid and 2-methyl tridecane were isolated from akju by barley 3-(Methylthio)-1-propanol. hexanoic acid ethyl ester, butanoic acid monomethyl ester, tridecanoic acid, ethyl tetramethyl cyclopentadiene and 1,5-diaza-2,9-diketocyclotetradecane were isolated from takju by wheat flour. Major volatile flavor components were acetic acid ethyl ester, 3-methyl-1-butanol, acetic acid and 2-phenylethanol.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.10-10
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• 2017

Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.503-506
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• 2008

'Saenuri' is a new japonica rice variety developed and registered by the rice breeding team of Department of Rice and Winter Cereal Crop, NICS, RDA in 2007. This variety was derived from a cross between Gyehwa17 with lodging tolerance and high yield potential, and HR14026-B-68-6-1-5 with resistance to diseases and good eating quality. This variety has about 124 days growth duration from transplanting to harvesting in west-southern coast, Honam and Youngnam plain of Korea. It is about 78 cm in culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows moderately resistance to blast, and resistance to bacterial blight pathogen races from K1 to $K_3$ and stripe virus, but susceptible to other major diseases and insect pests. The milled rice of "Saenuri" exhibits translucent, relatively clear non-glutinous endosperm and midium short grain. It has similar amylose content of 19.0% and lower protein content of 6.1%, and good palatability of cooked rice compared with Nampyeongbyeo. The milled rice yield performance of this variety is about 5.71MT/ha in local adaptability test for three years. "Saenuri" would be adaptable to west-southern coast, Honam and Youngnam plain of Korea.