• Korean Journal of Weed Science
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• v.31 no.3
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• pp.279-288
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• 2011

To suggest the weed management technique for environment friendly rice cultivation, we investigated occurrence patterns of weeds, the actual condition of weed management, and rice yield at the environment friendly agricultural complex located in Honam and Chungnam regions. The practical performance of weed management was relatively satisfactory in decreasing order of agricultural technique with golden-apple-snail (GAS) > agricultural technique with duck (Duck) > agricultural technique with rice bran (RB) > agricultural technique with soft-shelled turtle (ST). In the rice fields employed by agricultural technique with GAS, the dominant weeds were Echinochloa crus-galli, Ludwigia prostrata, Monochoria vaginalis, Sagittaria trifolia, and Aneilema keisak. However, E. crus-galli, M. vaginalis, L. prostrata, Aeschynomene indica and Bidens frondosa were found as dominant weeds at the fields using the Duck and E. crus-galli, M. vaginalis, L. prostrata, Polyganum hydropiper and Eleocharis kuroguwai at the fields using RB. In comparison of rice yield ($5.2\;MT\;ha^{-1}$) obtained from the conventional cultivation using herbicides, about 93% was reached by Duck, about 91% by GAS, about 92% by RB, and about 78% by ST. When rice qualities obtained from environment friendly rice cultivation were compared with those from the conventional cultivation, the producing rates of perfect kernel, immature kernel, immature opaque kernel, cracked rice, and damaged kernel were lower in the former cultivation, whereas contents of protein, amylose, and fatty acid were similar in the two cultivation methods. The problems found in the environment friendly agriculture were poor plowing and harrowing, carless irrigation management, and geological poor condition as cultivation area with cold water. These have caused severe infestation of weeds, frequent incident of disease and insect pest, and rice lodging. This resulted in reduction of rice yield as high as about 32 to 79% as compared with the conventional cultivation using herbicides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.234-242
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• 1987

Rough rice samples of four rice varieties were collected from twenty five locations through the country just after 1986 rice growing season. Various characteristics related to rice grain quality were observed to clarify the degree of locational variation of physico-chemical properties, and cooking and eating quality of rice grains. Grain weight, grain shape, degree of translucency and chalkiness of rice grain, amylogram properties of rice flour, water uptake during cooking, and cooked rice appearance were different between varieties tested. High degree of locational variation were found in following characteristics, degree of translucency and chalkiness of rice grain, water uptake during cooking, cooked rice appearance and amylogram properties. Eating quality of cooked rice indicated by sensory score showed different tendency of locational variation between rice varie-ties tested, and locations produced rice grains showing better eating quality were not coinside with among varieties tested. Grain weight, degree of translucency and chalkiness of rice grain, and cooked rice appearance of rice samples showing better eating quality were quite different to rice grains showing poor eating quality. Rice having better eating quality of a japonica variety, Chucheong, showed higher value of peak and final viscosity, viscosity after cooling, consistency and set back on amylograph compared with those of poor eating quality rices, and break down value of better rice was lower than that of poor rice. However, a Tongil type variety, Taebaek, did not show any consistent difference between better and poor rices. Rice samples from six locations in Chucheong and four locations in Taebaek showed special properties on amylogram compared with other rices collected in this study.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.750-756
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• 2014

This study was performed to understand the effect of cultivation periods on the physicochemical characteristics of the starch of five sweetpotato cultivars, cultivated in Muan, Korea. Starch, protein, and ash contents increased with increased cultivation period, whereas amylose content decreased. Rapid viscosity analysis showed that the pasting temperature, peak viscosity, breakdown, setback and final viscosity increased with increased cultivation period. However, trough and final viscosity decreased. Although the onset temperature and peak temperature values increased, the conclusion temperature did not show any consistent patterns by differential scanning calorimetry. X-ray diffraction showed that the starch samples had C-type crystallinity irrespective of the cultivation period and cultivar. The starch granules were dominantly round and oval, or polygonal irrespective the cultivation period. The bigger the particle size was, the longer the cultivation period was.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.172-183
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• 2017

Germinated brown rice (GBR) has received considerable attention over the last decade as a means of enhancing the nutritional value and health-promoting functions of rice. The effect of germination on the physicochemical and textural properties of brown rice (BR) was investigated in different rice varieties (Samkwang, Misomi, Chindeul, and Hyeonpum). Cooking properties, such as water absorption, expanded volume, and soluble solids were significantly increased by germination in all rice varieties. Textural properties (hardness, toughness, adhesiveness, and stickiness) of cooked samples were determined using a texture analyzer. Hardness and toughness were decreased by germination, whereas stickiness and adhesiveness increased significantly. These results revealed that germination leads to improvements in the cooking and eating properties of BR. In Rapid Visco Analyzer (RVA), significant reductions were observed for peak viscosity, break down, set back, and final viscosity after germination. Although the amylose content of Misomi was slightly decreased by germination, that of other varieties increased significantly. Germination induced no noticeable change in the average chain length of amylopectin in Misomi, Chindeul and Hyeonpum, but led to a significant increase in Samkwang.

• Food Science and Preservation
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• v.24 no.7
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• pp.908-914
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• 2017

Cold plasma (CP) was applied to examine microbial safety and physicochemical properties of rough rice. CP was generated in a square-shaped plastic container (250 W, 15 kHz, ambient air) and dielectric barrier discharge plasma treatment was applied for periods of 0, 10, and 20 min during 2 weeks at 4 and $25^{\circ}C$. As a result of observing changes in growth of microorganisms, 3.46-3.86 log CFU/g of total aerobic bacteria and 2.27-2.86 log CFU/g of mold were detected in the early stage of storage. The growth of total aerobic bacteria and mold was increased depending on the storage temperature and period, but there was no big difference between cultivars. Microbial analysis after storage showed that microorganisms of plasma-treated group were less grown approximately 1.50 log CFU/g. Moisture content of rough rice was decreased by storage temperature and periods. As for the amylose content, changes in the content by plasma were not observed in Samkwang, Cheongpum and Misomi, whereas Palbangmi showed a tendency to increase. The results of this study indicated that CP treatment improved the microbial quality of rough rice, but further studies should be conducted to reduce the deterioration of sensory quality induced by CP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.519-525
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• 2012

Effects of cultivated conditions on antioxidant compounds and antioxidant activities of sweet potatoes (Ipomoea batatas (L.) Lam) were determined. The cultivated variety was Shinyulmi, and they were cultivated in a conventional culture, successful cropped hairy vetch culture, successful cropped barley cultivation, successful cropped rye cultivation, successful cropped mix-seeding of hairy vetch and barley, successful cropped mix-seeding of hairy vetch and rye, and not fertilizer. The brix degree, moisture, protein, and ash content of the sweet potatoes did not significantly change with the cultivated conditions. However amylose, total dietary fiber, and mineral content had significant changes. The total polyphenol, flavonoid, and tannin content of the methanolic extracts of the sweet potato's pericarp showed significant differences from cultivated conditions, however, the sweet potato's sarcocarp did not significantly change. The highest DPPH and ABTS radical scavenging activities of the methanolic extracts of the sweet potatoes were 958.81 and 663.53 mg TE/100 g in the sweet potato's pericarp on the successful cropped hairy vetch culture. Generally, there was a difference in antioxidant compound content and radical scavenging activity on the methanolic extract of sweet potato with cultivated conditions.

• Journal of Life Science
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• v.22 no.12
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• pp.1628-1636
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• 2012

This study examined the antioxidant activity of the dark purple rice seeds from the rice line, MGI079, derived from insertional mutagenesis. The contents of polyphenolic compounds were 1.3 and 1.9-fold higher in the MGI079-2-1 and MGI079-2-6 rice lines than in the donor cultivar MGI079. Flavonoid contents were 6.4-fold higher in the MGI079-2-1 line. The MGI079-2-1 line showed a 24.4-fold higher activity in DPPH free radical scavenging compared to the MGI079 line. The anthocyanin content of the MGI079-2-6 line was more than 106.4-fold higher than the MGI079 line and 1.4-fold higher than the Heugnam line. Anthocyanin content in colored rice grains was negatively correlated with Hunter's L, a, and b values, with the correlation coefficients of $-5.64^{**}$, $5.21^{**}$ and -1.15, respectively. The grain length/width of a mutant of MGI079 segregated to a medium and bold type compared to the medium type of MGI079. However, the 1,000 grain weight was decreased to 13.6~19.6 g compared to 19.8 g for MGI079. Amylose content of the endosperm was 5.6~23.8% higher than in the MGI079 line. The grain of mutants of MGI079 was distinguished by its starch characteristics. The higher antioxidant activity of the MGI079-2-1 and MGI079-2-6 lines indicated functional characteristics associated with high-value resources, so future breeding should focus on the development of pigments in colored rice in new varieties.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.721-726
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• 2010

The objective of this study was to evaluate several varieties of aseptic-packaged cooked rice including Juanbyeo. Quality evaluations, such as by amylose, setback, toyo values and amylograms, were significantly higher in the Juanbyeo as compared to other samples. In addition, the Juanbyeo aseptic-packeged cooked rice showed significantly higher palatability characteristics and had a greater water absorption ratio than the other samples. For cold cooked rice, the relationship between palatability and texture was significantly high (p<0.01). Ilpumbyeo showed high scores for taste as a hot cooked rice, but as a cold cooked rice taste scores were lower than other samples. In the case of Juanbyeo cold cooked rice flavor was improved. When the Juanbyeo aseptic-packaged cooked rice was reheated in a microwave oven, it had better palatability than other varieties. Thus, the results of this study suggested that Juanbyeo can be effectively utilized as aseptic-packaged cooked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.275-284
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• 2017

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely 'top quality rice') cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. 'Hiami' showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: 'Younghojinmi' and 'Mipum' in Daegu, 'Daebo', 'Samgwang', Chilbo' and 'Younghojinmi' in Gumi, 'Samgwang', 'Jinsumi' and 'Sukwang' in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.547-551
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• 2009

A new commercial rice variety "Chilbo" is a japonica rice (Oryza sativa L.) with resistance to rice stripe virus and high grain quality. It was developed by the rice breeding team of Yeongdeog Substation, NICS, RDA in 2007. This variety was derived from a cross between "Yeongdeog 26" with wind tolerance and lodging resistance and "Koshihikari" with good grain quality. A promising line, YR21324-119-3-2 was selected by a pedigree breeding method and designated as "Yeongdeog 44" in 2004. Regional adaptation yield trials were carried out at eleven locations from 2005 to 2007. As a result, "Yeongdeog 44" was released as a high yielding rice variety with high grain qualilty and virus resistance with the name of "Chilbo". It is short 76cm in culm length and has medium-late growth duration. This variety is resistant to stripe virus and middle resistant to leaf blast disease. It is also tolerant to cold, dried wind. Milled rice kernel of "Chilbo" is translucent, clear in chalkiness. Panel test proved that and it has good eating quality. Head rice ratio of Chilbo is high compared to the check variety, Hwaseongbyeo. Yield potential of "Chilbo" in milled rice is about 5.57MT/ha at ordinary fertilizer level of local adaptability test. This variety would be adaptable to Yeongnam plain, south & east-south coastal, south mid-mountainous, middle plain area of Korean peninsula.