• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.207-213
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• 1999

Thirty-eight glutinous rice varieties were classified into nine groups on the scatter diagram by the upper two principal components (56% contribution to the total information) based on eleven physicochemical characteristics including the viscograms and physical properties of cooked rice. The first principal component was the factor mainly associated with the viscogram characteristics of rice flour emulsion and the second was the factor chiefly related to the physical properties of cooked rice and water absorbability of rice grain. Indica glutinous rices were clearly distinguished from japonica ones by the first principal component score. Javanica glutinous rices were widely distributed on the intermediate zone between indica and japonica or on several japonica rice groups. Significant positive or negative correlations were found among water absorption rates of rice grain, physical properties of cooked rice, and viscogram characteristics of rice flour. Especially in japonica glutinous rices, the breakdown and setback viscosities of rice flour were closely associated with the alkali digestion value of milled rice and the stickiness of cooked rice. The frequency ratio of short glucose chains (A-chain) to intermediate glucose chains (B-chain), the ratio of B- chains to long glucose chains (C-chain) and the relative frequency of A- or B-chain fractions representing the amylopection structure of rice starch was closely associated with the breakdown and setback viscosities of rice flour.

• 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 Metals and Materials
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• v.49 no.11
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• pp.845-852
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• 2011

The Spark Plasma Sintering(SPS) method offers a means of fabricating a sintered-body having high density without grain growth through short sintering time and a one-step process. A titanium compact having high density and purity was fabricated by the SPS process. It can be used to fabricate a Ti sputtering target with controlled parameters such as sintering temperature, heating rate, and pressure to establish the optimized processing conditions. The compact/target(?) has a diameter of ${\Phi}150{\times}6.35mm$. The density, purity, phase transformation, and microstructure of the Ti compact were analyzed by Archimedes, ICP, XRD and FE-SEM. A Ti thin-film fabricated on a $Si/SiO_2$ substrate by a sputtering device (SRN-100) was analyzed by XRD, TEM, and SIMS. Density and grain size were up to 99% and below $40{\mu}m$, respectively. The specific resistivity of the optimized Ti target was $8.63{\times}10^{-6}{\Omega}{\cdot}cm$.

• Journal of Powder Materials
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• v.26 no.2
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• pp.132-137
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• 2019

Tungsten carbide (WC) hard materials are used in various industries and possess a superior hardness compared to other hard materials. They have particularly high melting points, high strength, and abrasion resistance. Accordingly, tungsten carbide hard materials are used for wear-resistant tools, cutting tools, machining tools, and other tooling materials. In this study, the WC-5wt.%Co, Fe, Ni hard materials are densified using the horizontal ball milled WC-Co, WC-Fe, and WC-Ni powders by a spark plasma sintering process. The WC-5Co, WC-5Fe, and WC-5Ni hard materials are almost completely densified with a relative density of up to 99.6% after simultaneous application of a pressure of 60 MPa and an electric current for about 15 min without any significant change in the grain size. The average grain size of WC-5Co, WC-5Fe, and WC-5Ni that was produced through SPS was about 0.421, 0.779, and $0.429{\mu}m$, respectively. The hardness and fracture toughness of the dense WC-5Co, WC-5Fe, WC-5Ni hard materials were also investigated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.77-83
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• 1974

This experiment was conducted to study the effexts of seeding time and varieties on yield components, protein and oil content of soybean. Four varieties of soybean(Chung Buk Baek, Iksan, Keum doo, Chang dan Baek mok)wrere applied in this experiment and were seeded at May 15th, June 5th, and June 25th, the results obtained are as follows. 1.When the soybean was seeded at May 15th, stem height, stem diameter and number of nodes on main stem came to an end about 70days after seeding. In case that the seeding time was delayed 20 days and 40 days from May15th, respectively, the time to be almost cimpleted the growth of the characteristics was shortened 10days and 20days during ther debelopment. Among varieties, Chung Buk Beak grew faster than any other varieries. 2.When seeded at May 15th, the plants produced many pods, and had high proportion of branch pods. When seeded late, the proportion of branch pods were low. Branches had large proportion of empty pods and one grain pods, but on main stem, the proportion of two grain pods and three grain pods were more than that of branch. Among varieties, Chung Buk Baek had high proportion of two and three grain pods, Keum doo and Chang dan Baek mok had high proportion of one and two grain pods, and Iksan had high proportion of one and three grain pods. 3.Tields were less by the late seeding.The proportion if decreased yields to the yields when seeded at May 15th, that of Chung Buk Baek was decreased 6% when seeded at June 5th and 14% when seeded at June 25th, that of Ik san was decreased 9% and 17%, that of Keum doo decreased 15% and 26% and that of Chang dan Baek mik decreased 18% and 27%. 4.Protein content was highest in the plots seeded on May 15th, but oil content was highest in the plots seeded in June 25th. Among varietiesm Xhang dan Baek mok had the highest proportion of protein content and Iksan had the highest of oil content.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.63-77
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• 1997

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.122-123
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• 1992

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.10a
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• pp.62-63
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• 1995

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.56-57
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• 1988

• Food Science of Animal Resources
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• v.42 no.1
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• pp.18-33
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• 2022

Beef contains functional fatty acids such as conjugated linoleic acid and longchain fatty acids. This review summarizes results from studies comparing the fatty acid composition of beef from cattle fed either grass or grain-based feed. Since functional lipid components are contributed through dietary consumption of beef, the fatty acid composition is reported on mg/100 g of meat basis rather than on a percentage of total fat basis. Beef from grass-fed contains lesser total fat than that from grain-fed in all breeds of cattle. Reduced total fat content also influences the fatty acid composition of beef. A 100 g beef meat from grass-fed cattle contained 2,773 mg less total saturated fatty acids (SFA) than that from the same amount of grain-fed. Grass-fed also showed a more favorable SFA lipid profile containing less cholesterol-raising fatty acids (C12:0 to C16:0) but contained a lesser amount of cholesterol-lowering C18:0 than grain-fed beef. In terms of essential fatty acids, grass-fed beef showed greater levels of trans-vaccenic acid and long-chain n-3 polyunsaturated fatty acids (PUFA; EPA, DPA, DHA) than grain-fed beef. Grass-fed beef also contains an increased level of total n-3 PUFA which reduced the n-6 to n-3 ratio thus can offer more health benefits than grain-fed. The findings signify that grass-fed beef could exert protective effects against a number of diseases ranging from cancer to cardiovascular disease (CVD) as evidenced by the increased functional omega-3 PUFA and decreased undesirable SFA. Although grain-fed beef showed lesser EPA, DPA, and DHA, consumers should be aware that greater portions of grain-fed beef could also achieve a similar dietary intake of long-chain omega-3 fatty acids. Noteworthy, grain-fed beef contained higher total monounsaturated fatty acid that have beneficial roles in the amelioration of CVD risks than grass-fed beef. In Hanwoo beef, grain-fed showed higher EPA and DHA than grass-fed beef.