• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.657-664
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• 2004

Titanium sulfate supported on $TiO_2$was prepared by impregnation of powdered $TiO_2$with an aqueous solution of titanium sulfate followed by calcining in air at high temperature. For Ti$(SO_4)_2/TiO_2$ samples calcined at 300 $^{\circ}C$, no diffraction lines of titanium sulfate are observed at $Ti(SO_4)_2$loading up to 30 wt%, indicating good dispersion of $Ti(SO_4)_2$ on the surface of $TiO_2$. The acidity of the catalysts increased in proportion to the titanium sulfate content up to 20 wt% of $Ti(SO_4)_2$. 20 wt% $Ti(SO_4)_2/TiO_2$ calcined at 300 $^{\circ}C$ exhibited maximum catalytic activities for 2-propanol dehydration and cumene dealkylation. The catalytic activities for these reactions, were correlated with the acidity of catalysts measured by ammonia chemisorption method.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.50-58
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• 1999

This study was carried out to investigate the growth characteristics and propagation methods of L. obtusiloba as a woody landscape plant. The results are obtained as follows: L. obtusiloba was dioecious shrub and shaped with bush type. Leaves were ovate, obtuse, cordate, 7.05 cm long, 7.20 cm wide, and petiole 2.0 cm long. Flowers of L. obtusiloba were diclinous. Soil acidity ranged from pH 4.06 to 5.53 with the lowest at the Mt. Soo-Ri. Mt. Soo-Ri located near factory district, which was considered to damaged by environmental deteoration. While soil organic matter was highest at Mt. Soo-Ri, inorganic nutrients were low. L. obtusiloba grows in the area with low soil acidity and low content of inorganic. Therefore it seemed to be tolerant to air pollution. L. Obtusiloba was high seed germination rate in the plug box and its shoots were longer than seeding box and softwood cutting of L. obtusiloba showed the rooting rate of 50% at 5,000ppm on June 23. To develop a mass propagation method of Korean native L. obtusiloba through an axillary bud culture as a woody landscape plant, about 2∼3 cm shoots induced from explant were subcultured to new media contained different growth regulators. Shoots multiplied most effectively on a WPM containing 1.0 mg/l BA, producing 5.5 shoots with a shoot length of 2.5 cm per shoot explant.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.34-37
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• 1970

The variation of acidity, pH and oxidation-reduction potentials of Dongchimi (a kind of large raddish pickle) during its fermentation was investigated. Estimation of oxidation-reduction potentials was carried out by the electric method. 1. Acidity was increased-3.5% by lactic acid and pH was decreased 3.4 during Dongchimi fermentation. 2. In Dongchimi, oxidation-reduction potentials was comparatively high (rH above 10) in the earlier stage and then decreased rapidly from rH 15 to 2.0 but slightly increased rH 5.0 in the later stage of the fermentation. 3. It is suggested that the earlier stage of fermentation was more aerobic condition than the later stage.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.12-17
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• 2009

The effect of kimchi, traditional Korean fermented vegetables, on inactivating food-borne pathogens and the kimchi factors affecting the antimicrobial activity were investigated. More cells of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium were inactivated in the kimchi that had low pH and high titratable acidity. Of the raw ingredients in kimchi, raw garlic showed the strongest antimicrobial activity against the pathogens. When kimchi was fermented at 0, 4, 10, or $20^{\circ}C$ to pH 4.4, higher kimchi fermentation temperature resulted in higher titratable acidity. The greatest inactivation of S. typhimurium occurred in kimchi fermented at $20^{\circ}C$, while L. monocytogenes were inactivated in kimchi fermented at $0^{\circ}C$ in situ. This study showed that appropriately fermented kimchi can inactivate various food-borne pathogens and that the fermentation temperature of the kimchi is an important factor in determining the ability of the kimchi to inactivate specific pathogens. Lactic acid bacteria (LAB) multiplication and organic acids produced according to LAB metabolism play a role in inactivating food-borne pathogens in kimchi.

• Journal of the Korean Society of Food Culture
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• v.30 no.3
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• pp.377-386
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• 2015

The purpose of this research was to appraise physicochemical properties by utilizing different Mit-sool, Juk, Seolgi-tteok, and Godubap, to produce traditional liquor. In all experimental plots, pH and amino acidity tended to increase with duration of fermentation. Titratable acidity displayed a very high number on the second day but then tended to decrease as fermentation progressed. Sugar contents were highest on the fourth day and tended to decrease with time. Alcohol content increased sharply at the initial stage of fermentation and increased gradually. On the 15th day, traditional liquor made with Godubap recorded the highest alcohol content. Common free sugar components were glucose and sorbitol. Common free organic acid components were lactic, succinic, citric, tartaric, malic, and acetic acids. Volatile flavor compounds were six alcohols, five esters, three aldehydes, and two ketones. Regarding overall acceptability in the sensory evaluation, traditional liquor using Seolgi-tteok as Mit-sool scored the highest. Overall, even though different types of Mit-sool had different physicochemical properties, there were no significant differences in volatile flavor compounds or sensory evaluation scores.

• Korean journal of food and cookery science
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• v.32 no.2
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• pp.211-221
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• 2016

Purpose: This study was conducted to investigate the physical and sensory properties of seasoned powders utilizing tomato. Methods: Tests of salted tomato powder were performed for the physiochemical properties (moisture content, pH value, titratable acidity, color value, salinity content, and solubility content), sensory characteristics and sensory preference. Results: Moisture content of salted tomato powder containing fully ripened tomato (RT) was higher than that of salted tomato powder containing cherry tomato (CT), with the exception of CT 10%. The pH values of RT was relatively high and increased salt addition increased the pH as well. The titratable acidity was opposite the result of pH measurement. The color values of RT was higher than that of CT for the L, a, and b values. The salt content of RT was higher than that of CT. RT 10% showed the highest dissolution followed by CT 10%. In addition, the sensory preference for CT 10% was the highest, with the best scores for appearance and taste. Conclusion: It was concluded that 10% salt addition is the most suitable sensually for the manufacture of salted tomato powder.

• Carbon letters
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• v.9 no.1
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• pp.8-16
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• 2008

Oxidized activated carbons were prepared by reacting steam-activated carbon developed from pecan shells with nitric acid of varying strength (15, 30, 45 and 60%). The textural properties and the chemistry of the surface of the non-oxidized and of the oxidized carbons were determined from nitrogen adsorption and base neutralization capacities. The uptake of Pb(II) and Cd(II) from aqueous solution by these carbons was determined by kinetic and equilibrium experiments as well as by the column method. Treatment with nitric acid brought about drastic decrease in surface area and remarkable increase in the pore size of the carbon with these changes depending on the strength of nitric acid. Nitric acid increased the surface acidity by developing new surface oxygen functional groups of acidic nature. $HNO_3$-oxidized carbons exhibited high adsorption capacities for Pb(II) and Cd(II). The adsorption of these ions increased with the decrease of the surface pH of the carbon and with the increase of the solution pH from 2.5 to 6 and 7. The amount adsorbed from lead and cadmium was also related to the amount of surface acidity, the pH of the point of zero charge and on some metal ion parameters. Cadmium and lead uptake by the investigated carbons followed pseudo-second order model and the equilibrium sorption data fitted Langmuir adsorption model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.852-857
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• 1998

Three kinds of kimchi using Chinese cabbage, leafy radish and mustard leaf were prepared by conventional method and stored at 5$^{\circ}C$ or 2$0^{\circ}C$ for 13 dyas. During storage at both temperatures, changes of the amounts of salt and ascorbic acid, pH and total acidity were determined, and the relationship of the decomposition of chlorophylls with the production of their derivaties was studied. At both storage temperatures, salt concentration of Chinese cabbage kimchi(3.7%), leafy radish kimchi(3.6%), mustard leaf kimchi(3.5%) was relatively constant during the entire storage period. However, pH and total acidity wre fluctuating with the remarkable changes during 3 days of storage. Ascorbic acid content was slowly decreased during the storage period and the decompositin rate of ascorbic and was greater at 2$0^{\circ}C$ than 5$^{\circ}C$. Among the kinds of kimchi tested, mustard leaf kimchi with the slow decomposition rate of ascorbic acid contained relatively high ascorbic acid content, while leafy radish kimchi contained the lowest content. At both storage temperatures, the production of pheophytin and pheophorbide from decomposition of chlorophyll was least in mustard leaf kimchi, but similar production rates in leafy radish and Chinese cabbage kimchi were observed.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.359-368
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• 2022

In this study, the quality characteristics of kimchi, such as its salinity, pH, and acidity, were measured and compared, and the HT-29 human colon cancer cells were used to show the anticancer effects of kimchi. The kimchi samples used herein included standard kimchi (SK), turnip kimchi (TK), and turnip-powder-added kimchi (TPK). The measured pH and acidity of TK and TPK showed no significant differences with those of SK. Compared to SK and TK, TPK had higher DPPH scavenging activity and higher total flavonoid content, confirming its antioxidant activity. The cancer cell growth inhibition rates of TK and TPK were significantly higher than that of SK. In HT-29 cells treated with TPK, the mRNA expression of Bcl-xL, an anti-apoptosis-related gene, was lower, and the mRNA expressions of the apoptosis-related genes Bax, Bad, and caspase-9 were higher. TPK showed significantly higher levels of mRNA expressions for the cell-cycle-related genes p53 and p21 than the other samples, in addition to suppression effects on cancer cell proliferation. Compared to SK, TK and TPK suppressed the growth of colon cancer cells and showed higher anticancer effects. Therefore, it is shown that kimchi with added turnip powder had high anticancer effects.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.403-411
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• 2021

This study was designed to evaluate the gastroprotective activity of cirsilineol in hydrochloric acid (HCl)/ethanol-induced gastric ulcer model. Cirsilineol was administered at the doses of 20 and 40 mg/kg in HCl/ethanol-induced rats. The gastroprotective ability was verified by determining the ulcer score, total acidity, hemoglobin, inflammatory cytokines, lipid peroxides, and enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT) in gastric tissue and serum biochemical analysis. The results showed a favorable increase in the hemoglobin level, antioxidant enzymes (SOD and CAT), restored electrochemical balance (carbon dioxide & anion gap) while a noticeable decrease in ulcer index, total acidity, lipid peroxides, inflammatory cytokines (interleukin-1 beta [IL-1β], IL-6, and tumor necrosis factor alpha) in rats treated with the cirsilineol. The serum biochemical analysis on liver markers (alkaline phosphatases, alanine aminotransferase, and aspartate aminotransferase), kidney markers (urea, creatinine, albumin, globulin, total protein), and lipid profile (triglyceride, high-density lipoprotein, total cholesterol) were attenuated by cirsilineol treatment in rats. Histopathology showed enhanced gastric protection and preserved the integrity of gastric mucosa upon cirsilineol administration. These results ultimately suggest that cirsilineol has gastroprotective effects that prevent the development of gastric ulcer.