• Analytical Science and Technology
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• v.13 no.5
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• pp.652-658
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• 2000

Chemical degradation of aqueous humic acid by ozonation was studied with respect to the direct reactions of ozone and the indirect reactions due to its preliminary decomposition to secondary oxidant, OH radical. This was characterized by analyzing TOC, $UV_{254}$ and ozone consumption measured in different experimental conditions in which ozone reacted in the presence of various concentrations of $H_2O_2$ and $HCO_3{^-}$ concentrations ranging from 20 to 100 mg/L. and different pH (5-9). The results suggest that the TOC removal is mainly dependent on indirect reactions of OH radical whereas $UV_{254}$ reduction is mainly dependent on direct reactions of ozone with humic acid molecules. It has been also found that ozone consumption was most likely to be affected by pH and alkalinity in the solution.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.164-168
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• 2012

We investigated for the production of biological bio-ethanol from Laminaria japonica using the hydrolysis reaction of enzymes and organic acids and the polysaccharide content was also analyzed. The composition of the polysaccharide was characterized as 65.99% alginate, 6.24% laminaran and 27.77% mannitol. The optimum concentration for reducing the sugar conversion by Laminaria japonica was found to be 1.874 g/L at an acetic acid concentration of 1.5%, $121^{\circ}C$ for 60 min, and for an ascorbic acid of 2.0%, 4.291 g/L was produced in the same condition. The enzyme hydrolysis such as alginate lyase and laminarinase contained the maximum 2.219 g/L reducing sugar. In the result of ethanol fermentation using hydrolysate of Laminaria japonica, the organic acid treatment showed a high of reducing sugar yield, but decreased the ethanol yield, and then the maximum ethanol production obtained was 1.26 g/L using the mixed treated of enzyme.

• Journal of agriculture & life science
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• v.44 no.1
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• pp.61-67
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• 2010

This study was to investigate the fructose, total fructan, polyphenol contents, and antioxidant activity of garlic treated acid and heat($100{\sim}140^{\circ}C$ for 2 hr). Optimum condition of acid hydrolysis of fructan was 0.3N $H_2SO_4$ and 5 min. As increasing heating temperature, fructose content was significantly increased from 17.1 to 189.9 mg/g whereas total fructan content was decreased from 248.1 to 2.0 mg/g. The fructan was mostly hydrolyzed by heating at $130^{\circ}C$ for 2 hr. The polyphenol contents was increased from 0.85 to 13.74 mg/g increasing heating temperature and also antioxidant activity was significantly increased. The polyphenol contents and antioxidant activity on acid hydrolysate after heating was slightly increased.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.2
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• pp.196-213
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• 2019

This paper attempts to analyze the contribution of different socioeconomic factors such as income, age, gender, household composition, education and employment status etc. to the difference between the Capital and Non-Capital Regions in the net wealth inequality of household in Korea. To this end, a two-stage Oaxaca-Blinder type decomposition is employed regarding the regional gap in the inequality of net wealth based upon the Recentered Influence Function of the Gini index for 'the 2018 Household Finance and Living Conditions Survey.' Despite the shortcomings of the survey data on wealth, the findings reveal that regional differences in income, marriage status (divorce), job type (agriculture, forestry and fishery related, and technical and assembly), family type (multi-cultural) variables deepen the regional gap in the net-wealth inequality, but employment status (full-time), job type (administrative and specialized, and service sales), household size variables mitigate the gap, and that regional differences in life cycles play an offsetting role.

• Polymer(Korea)
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• v.26 no.4
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• pp.492-500
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• 2002

Oxidized-polyacrylonitrile (oxy-PAN) was prepared by oxidation of PAN fiber at $240^{\circ}C$, followed by base catalyzed hydrolysis reaction. The chemical structure of PAN fiber in various pH conditions was characterized by $^{13}C-NMR$ spectroscopy. The characteristic contraction and expansion behavior of oxy -PAN fiber was observed in acidic and basic medium, respectively. In basic condition, water molecules might be absorbed into the fiber with the movement of charge balancing $Na^+$ ion, on the other hand, the water molecules seemed to be expelled in acidic condition to result in contraction. It was also observed that the facile chemical modification occurred due to free diffusion of aqueous reagent into the hydrophilic PAN fiber, and the morphology was affected by pH condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.811-814
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• 1993

Properties of a protease purified from Sarcodon asparatus(Berk.) S. Ito have been investigated. The enzyme displays as a glycosylated serine protease. The sequence for the 21 amino acids of the N-terminal side in the enzyme was determined by automated sequence analysis. The sequence was V-T-T-K-Q-T-N-A-P-W-G-L-G-N-I-S-T-T-N-K-L-.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.156-161
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• 1985

Physicochemical properties and characteristics on lintnerization of sweet potato starches from Wouki(the dry type), Shinmi(the intermediate type) ana Chunmi(the moist type) were investigated. Swelling and gelatinization curves of these starches showed a two-stage process. Swelling powers of starches were higher in order of Shinmi, Chunmi and Wonki over a range of temperatures. Amylose content of Wonki was higher than those of other two. Hydrolytic patterns of three starches with 2.2 N HCI at $35^{\circ}C$ showed two distinct stages. Hydrolysis extents of Wonki starch were lower than those of Shinmi and Chunmi starches. X-ray diffraction patterns of native and lintnerized starches were the Ca crystalline type. The relative crystallinities of these starches were higher in order of Worki, Chunmi and Shinmi.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.97-104
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• 2002

Protein hydrolysate was prepared as a natural flavor stock from the sharp toothed eel (Muraenesox cinereus) mince using com-mercially available proteolytic enzymes, Alcalase, Neutrase, Protamex, and Flavourzyme. A 6 hr hydrolysis of mince, to which water of the equal weight of the mince was added, with $2\%$ (w/w, protein weight) Elavourzyme at $50^{\circ}$ yielded a hydrolysate of the highest acceptability. Removing the access lipid in liquified hydrolysate (not dehydrated) after enzyme hydrolysis, five times repetitive extraction using n-hexane (liquified hydrolysate : n-hexane=4 : 1, v/v) was effective, resulting in less than $1\%$ lipid content of the dehydrated-hydrolysate. The amino acid composition of the hydrolysate (prepared with Flavourzyme) was similar to that of the starting material. Hydrolysis led to an increase in concentration of not only total free amino acid but also free amino acid such as serine, glutamic acid, alanine, and methionine responsible for umami taste, especially up to about 40 times for methionine. Major free amino acids in amount were leucine, phenylalanine, valine, alanine, and isoleucine and they comprised about half of the total free amino acids, Moisture adsorption, fat adsorption, emulsifying capacity, and foaming capacity of the hydrolysate were 870.1 $\pm$ $7.9\%$, 352.0$\pm$ $5.3\%$, 50.3 $\pm$ $1.2\%$, and $87.5\pm$ $2.5\%$, respectively, and solubility was 83$\~$$84\%$ at acid pH range of 2$\~$4.

• Journal of the Korean Professional Engineers Association
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• v.29 no.5
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• pp.11-23
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• 1996

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2002.11a
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• pp.6-6
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• 2002