• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.39-44
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• 2002

To obtain the repression of off-odor and the improvement of food quality in b1ack bean chungkugjang (BBC), some baste components of BBC added with kiwi (BBCK) or radish (BBCR) and fermented at 42$^{\circ}C$ for 3 days were investigated. Although contents of free amino acids in BBC were lower than those of soybean chung-kugjang (SC), they increased by adding kiwi and radish homogenate to black bean, indication that two materials were effective to the enzymatic digestibility of soy protein during fermentation. Among organic acids, citric acid was the most abundant, followed by acetic acid and lactic acid. Fatty acid composition was high in the order of linoleic acid (44.28~54.24%), oleic acid (18.18~22.10%) and palmitic acid(9.93~15.51%). There was no significant difference in compositions of organic acids and fatty acids of chungkugjangs. Majar volatile compounds of BBC were 2.5-dimethyl parazine and trimethyl pyrazine. Contents of alkyl pyrazines that of contribute the characteristic aroma and flayer of BBCK and BBCR decreased as compared with those of SC, respectively. Uracil and UMP were major nucleic acid-related compounds in all four types chungkugjangs. Contents of the other nucleic acid-related compounds showed a similar trend in all chungkugjangs. In sensory evaluation, kiwi and radish were effective to repression of off-odor from chungkugjang. Sweet taste of stew of black bean chungkugjang was strong as compared with that of soybean chungkugjang, indicating that palatability of BBCK or BBCR was good.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.727-733
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• 1995

This stduy was attempted to establish the basic data for evaluating chemical components in the sap from birches(Betula platyphylla Sukatschev, Betula costata Trautv, Betula davurica Pallas), bamboos(Phyllostachys pubescens, Phyllostachys bambusoides, Phyllostachys nigra), Darae(Actinidia arguta). Calcium and potassium in five kinds of mineral detected in the sap were dominant mineral, magnesium, sodium and iron in order and calcium, potassium and magnesium are abundant in the sap from bamboo more than the other sample and the contents were 242.0~422.1mg/L, 793.8~ 2504.1mg/L and 72.6~165.9mg/L, respectively. Free sugars of the sap determined were glucose, fructose and sucrose, but maltose was not detected. The contents of glucose and fructose of the sap from Betula platyphylla Sukatschev(#2) were the highest and 42.1g/L and 36.9g/L, respectively. The detectabel nucleotides and their related compounds were CMP, UMP, GMP, IMP, AMP and hypoxanthine. The total contents of composition amino acids detected from eighteen kinds of the sap were in the range of 2.4~30.4mg%. The major amino acids were taurine, glycine, lysine, alanine and threonine in the sap from birch(#1, #2), glutamic acid and lysine in the sap from Betula costata Trauty(#3) and Betula davurica Pallas(#4), lysine, valine, alanine, serine, tyrosine and glutamic acid in the sap from bamboos, and glutamic acid, leucine, alanine in the sap from Darae.

• Applied Biological Chemistry
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• v.18 no.3
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• pp.167-176
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• 1975

As a study on the ATP-inhibited ribonuclease of Bacillus subtilis the screening work for obtaining the ATP-inhibited ribonuclease negative mutant were carried out. And mutant strain was selected by the treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG). For the selected strain the enzyme purification and some physiological properties were examined and the results obtained were as follows. 1. Among tested 1817 strains with the treatment of NTG, 101 strain was selected as a mutant strain. 2. ATP-inhibited ribonuclease was tentatively purified by several independent column chromatography. The results with Sephadex G-75 column were 30 times purification, 99% recovery, and 20 times purification, 98% recovery, respectively. 3. ATP-inhibited ribonuclease was purified by 60 times through acid treatment, ammonium fractionation, and two successive chromatography. 4. The purified ribonuclease were shown to be effectively concentrated in robonnclease content and to have reduced numbers of protein band on Disc electrophoresis. 5. This enzyme degraded single-stranded RNA to 2',3'-cyclic AMP, 2',3'-cyclic CMP, 2',3,-cyclic GMP, 2',3'-cyclic UMP and some unknown intermediates. The enzyme could not split double-stranded RNA.

• Geomechanics and Engineering
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• v.14 no.3
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• pp.247-255
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• 2018

Soil stabilization can make the soils becoming more stable by using an admixture to the soil. Lime stabilization enhances the engineering properties of soil, which includes reducing soil plasticity, increasing optimum moisture content, decreasing maximum dry density and improving soil compaction. Silica fume is utilized as a pozzolanic material in the application of soil stabilization. Silica fume was once considered non-environmental friendly. In this paper, the materials required are kaolin grade S300, lime and silica fume. The focus of the study is on the determination of the physical properties of the soils tested and the consolidation of kaolin mixed with 6% silica fume and different percentages (3%, 5%, 7% and 9%) of lime. Consolidation test is carried out on the kaolin and the mixtures of soil-lime-silica fume to investigate the effect of lime stabilization with silica fume additives on the consolidation of the mixtures. Based on the results obtained, all soil samples are indicated as soils with medium plasticity. For mixtures with 0% to 9% of lime with 6% SF, the decrease in the maximum dry density is about 15.9% and the increase in the optimum moisture content is about 23.5%. Decreases in the coefficient of permeability of the mixtures occur if compared to the coefficient of permeability of kaolin soft clay itself reduce the compression index (Cc) more than L-SF soil mix due to pozzolanic reaction between lime and silica fume and the optimum percent of lime-silica fume was found to be (5%+6%) mix. The average coefficient of volume compressibility decreases with increasing the stabilizer content due to pozzolanic reaction happening within the soil which results in changes in the soil matrix. Lime content +6% silica fume mix can reduce the coefficient of consolidation from at 3%L+6%SF, thereafter there is an increase from 9%L+6%SF mix. The optimal percentage of lime silica fume combination is attained at 5.0% lime and 6.0% silica fume in order to improve the shear strength of kaolin soft clay. Microstructural development took place in the stabilized soil due to increase in lime content of tertiary clay stabilized with 7% lime and 4% silica fume together.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.911-916
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• 1995

Even though the saps have been consumed as beverage in Korea for a very long period of time, a little research has been conducted on the chemical composition. We determined mineral, free sugar, composition amino acids and nucleotides in the sap of Gorosoe(Acer mono Max.) and Sugar Maple(Pseudo-sieboldianum Kom.) collected from Sancheong, Kurye and Hamyang. The contents of solid, crude protein and ash were 1.1~3.3%, 0.03~0.12% and 0.02~0.05% in the sap of Gorosoe and Sugar Maple, respectively. The detectable nucleotides were CMP, UMP, IMP, GMP, AMP and hypoxanthine. Free sugar that we determined in the sap of Gorosoe and Sugar Maple were sucrose, fructose and glucose, but maltose was not detected. The chief component of saccharides in the sap was sugar and ranged from 7.1 to 36.6g/L. Especially, the sucrose contents in the sap of Gorosoe and Sugar Maple from Hamyang were higher 3.7 and 2.2 times than those from the other samples. The prominent minerals in the sap were calcium and potassium. The calcium concentration was ranged from 99.0~153.3mg/L in the sap of Gorosoe and was ranged from 21.2~32.4mg/L in that of sugar maple. The sap of Gorosoe and Sugar Maple were composed of 18 and 15 kinds of amino acid respectively, and the total contents of amino acid were in the range of 0.7~29.3mg%. The major amino acids in the sap of Gorosoe were taurine, serine, glutamic acid and aspartic acid in decreasing order. Taurine contents in the sap of Gorosoe and Sugar Maple was found to be the dominant amino acid.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.245-251
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• 1983

Nucleic acid degrading enzymes (RNase, PDase, PMase) isolated from rice Makgeoly brewing were purified by DEAE-cellulose column technique and their enzymological properties were examined. Changes of nucleotides and their related substances during the brewing were also investigated. The results obtained were as follows: 1. RNase activity was increased in the earlier phase of brewing and then decreased after 3 days brewing, while PDase and PMase activities were decreased with the lapse of time. 2. The optimum pH of RNase was 5.0 and those of PDase and PMase were 6.0. Activities of these three enzymes were almost stable in the range of pH 6.0-7.0. 3. The optimum temperature of RNase and PDase were in the range of $55{\sim}60^{\circ}C$ and that of PMase was about $50^{\circ}C$. When RNase was treated at $100^{\circ}C$ for 10 min., 80% to of activity was lost PDase lost 90% of activity when heated at $70^{\circ}C$ for 10 min, while PMase was completely inactivated at the same condition. 4. $CU^{++},\;Zn{++}$ inhibited the activity of NRase, Activity of PMase was reduced about 30% by adding $10^{-3}M\;Na_{2}HPO_{4}$5. Until 4 day brewing, IMP was increased, while UMP, GMP, AMP were decreased gradually.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.163-168
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• 1984

The composition of amino acids and the related compounds of nucleotides in the dorsal muscle of sweet fish Hemibarbus labeo, Mandarin fish Siniperca scherzeri and read fish Gobius similis was analyzed by amino acid autoanalyzer and high performance liquid chromatography. The result showed that IMP was dominant in the nucleotides of all the dorsal muscle of the fishes and a less amount of UMP, hypoxanthine and AMP was detected. In the free amino acid composition, the important amino acids were taurine and histidine in sweet fish, taurine, glycine and histidine in cornet fish, taurine, histidine and alanine in mandarin fish, taurine, proline and threonine in read fish, respectively, and in all the dorsal muscle of fishes, taurine was the dominant amino acid. In the amino acid compositions of the muscle protein, glutamic acid, glycine, aspartic acid and lysine were reached to 44.0% of total amino acids in sweet fish, glutamic acid, aspartic acid, lysine and glycine were 43.5% in cornet fish, glutamic acid, aspartic acid, lysine and leucine were 43.3%, 43.5% of total amino acids in mandarin fish and read fish, respectively. Glutamic acid was the dominant amino acid in all the fresh fishes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.1-10
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• 1987

For surveying of constituents concerning the flavor of the dried tomato fruits, nonvolatile components such as minerals, sugars, free amino acids, nucleotides and lipids were analyzed and determined. Potassium, calcium and phosphorus were the major conatituents of ashes, but trace amounts of cadmium and lead were determined. Glucose and fructose were the major constituents in sugars, and the latter slightly showed higher value than the former. The content of total free amino acids was 8322.5mg%, and that of the major components such as asparagine, aspartic acid, urea. glutamic acid, ${\beta}-alanine$ and ${\gamma}-aminobuthyric$acid showed 58.01% to the total amount. The nucleotides were composed of CMP, UMP, GMP and IMP, and CMP among them showed the highest value as about 58.07% to the total amount. On the other hand, IMP showed the lowest one. The major components of the total fatty acids from the saponifiable fraction in the lipids were $C_{18:2}$, $C_{18:1}$ and $C_{16:0}$ and those of the total sterols from unsaponifiable one were stigmasterol and ${\beta}-sitosterol$.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.152-156
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• 1996

Taste components of traditional kochujang from 55 households were investigated. The major free sugars in traditional kochujang (fermented hot pepper-soybean paste) were glucose $(8.21{\pm}5.62%)$ and maltose $(6.95{\pm}7.27%)$ and the minors were fructose $(1.88{\pm}1.27%)$ and sucrose $(1.05{\pm}1.21%)$. Succinic $(901.83{\pm}826.23\;mg%)$, citric $(484.16{\pm}242.89\;mg%)$ and lactic $(381.63{\pm}367.88\;mg%)$ acids in traditional kochujang were found in large amounts and acetic, oxalic, and formic acids in smaller amounts. The traditional kochujang contained large amounts of proline $(10.66{\pm}6.27\;mg%)$, glutamic acid $(9.27{\pm}10.97\;mg%)$, aspartic acid $(9.14{\pm}5.84\;mg%)$, lysine $(6.19{\pm}6.66\;mg%)$, and serine $(5.72{\pm}3.79\;mg%)$, and the total free amino acid content was 64.35mg%. Among the nucleotides and their related compounds in traditional kochujang, CMP $(42.90{\pm}28.16\;mg%)$ were the most abundant major compounds and hypoxanthine $(6.86{\pm}3.45\;mg%)$, IMP $(5.59{\pm}5.84\;mg%)$, inosine $(4.58{\pm}6.91\;mg%)$ and GMP$(3.36{\pm}3.93\;mg%)$ were found in smaller amounts, and AMP and UMP were also found in minor.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.481-499
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• 2022

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/ F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose-galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.