• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.195-204
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• 1996

This study was conducted to enhance the shelf-life of Kimchi and to make the unique taste of Kimchi by fermentation control. Kimchis, Prepared by win baechu soaked in 10% salt solutions containing 0.2-0.3% organic acids (OS-Kimchi), acetic acid, citric acid (CA-Kimchi), lactic acid, its mixtures and formic acid+acetic acid+fumalic acid+malic acid+citric acid(FAFMC), were examined for pH, titratable acidify, sensory evaluation, the number of total microbe and lactic acid bacteria, content of organic acids and texture during fermentation at 1$0^{\circ}C$. The decrease of pH and the increase in acidity, CA-Kimchi showed lower than those of control and various OS-Kimchi. Total microbe, lactic acid bacteria, content of lactic acid of CA-Kimchi were lower than those of control. The hardness of CA-Kimchi measured instrumentally was higher than that of control. Sensory scores of CA-Kimchi were also lower than those of control, so the Kimchi maintained good crispness and overall taste.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.499-504
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• 2009

Erythrosine is used a food coloring, ink and dye, etc. but erithrosine is rarely used in United States due to its known hazards. The adsorption characteristics of erythrosine by granular activated carbon were investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for erythrosine were largely improved by pH control. When the pH was 11 in the sample, the erythrosine could be removed 98% of initial concentration. It was estabilished that the adsorption equilibrium of erythrosine on granular activated carbon was successfully fitted by Freundlich isotherm equation in the concentration range from 10mg/L to 1,000mg/L. The characteristics of breakthrough curve of activated carbon packed column depend on the design variables such as initial concentration, bed height, and flow rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.121-126
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• 1994

The present study was designed to investigate effects of the addition of potato homogenates on fermentation control of salted anchovy. With the addition of $8\%$ (w/w) potato homogenates(P), amino-N content and pH were maintained at lower values in the muscle and juice of salted anchovy during all fermentation periods, And high values in external appearance of the salted and fermented anchovy-body during fermentation period were recorded. Consequently, the suppressing effect on the fermentation of salted anchovy of the addition of $8\%$ (w/w) potato homogenates was proved. As for the factors related to the suppressive effects on fermentation, there was no change in amino-N content, and viable cell counts and pH values were maintained.

• Journal of Life Science
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• v.21 no.4
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• pp.509-514
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• 2011

Maloactic fermentation (MLF) occurs after completion of alcoholic fermentation and is mediated by lactic acid bacteria (LAB), mainly Oenococcus oeni. Kiwi wine more than commercial grape wine has the problem of high acidity. Therefore, we investigated the optimal MLF conditions for regulating strong acidity and improving the quality properties of wine fermented with Kiwi fruit cultivated in Korea. For alcohol fermentation, industrial wine yeast Saccharomyces cerevisiae KCCM 12650 strains and LAB, known as MLF strains, were used to alleviate wine acidity. First, the various experimental conditions of Kiwi fruit, initial pH (2.5, 3.5, 4.5), fermenting temperature (20, 25, $30^{\circ}C$), and sugar contents (24 $^{\circ}Brix$), were adjusted, and after the fermentation period, we measured the acidity, pH, and the change in organic acid content by the AOAC method and HPLC analysis. The alcohol content of fermented Kiwi wine was 12.75%. Further, total acidity and pH of Kiwi wine were 0.78% and 3.5, respectively. Total sugar and total polyphenol contents of Kiwi wine were 38.72 mg/ml and 60.18 mg/ml, respectively. With regard to organic acid content, the control contained 0.63 mg/ml of oxalic acid, 2.99 mg/ml of malic acid, and 0.71 mg/ml of lactic acid, whereas MLF wine contained 0.69 mg/ml of oxalic acid, 0.06 mg/ml of malic acid, and 3.12 mg/ml of lactic acid. Kiwi wine had lower malic acid values and total acidity than control after MLF processing. In MLF, the optimum initial pH value and fermentation temperature were 3.5 and $25^{\circ}C$, respectively. Therefore, these studies suggest that establishment of optimal MLF conditions could improve the properties of Kiwi wine manufactured in Korea.

• Clean Technology
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• v.16 no.4
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• pp.277-283
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• 2010

Eosin Y is used a colorant and dye but eosin Y is harmful toxic substance. In this study, the adsorption characteristics of granular activated carbon have been investigated for the adsorption of eosin dye dissolved in water. The effects of initial dye concentration, contact time, pH and temperature on adsorption of eosin by a fixed amount of activated carbon have been studied in batch adsorber and fixed bed. The adsorptivity of activated carbon for eosin Y were largely improved by pH control. When the pH was 3 in the sample, the eosin Y could be removed 99% of initial concentration (10 mg/L). The adsorption equilibrium data are successfully fitted to the Freundlich isotherm equation in the temperature range from 293 to 333 K. The estimated values of k and ${\beta}$ are 19.56-134.62, 0.442-0.678, respectively. The effects of the operation conditions of the fixed bed on the breakthrough curve were investigated. When the inlet eosin Y concentration is increased from 10 to 30 mg/L, the corresponding adsorption breaktime appears to decrease from 470 to 268 min at bed height of 3 cm and a constant flow rate of 2 g/min. When the initial eosin Y flow rate is increased from 1 to 3 g/min, the corresponding adsorption breaktime appears to decrease from 272 to 140 min at bed height of 3 cm and inlet concentration of 10 mg/L. Also, breaktime increased with increasing bed height at flow rate of 2 g/min and inlet concentration of 10 mg/L. And length of adsorption zone showed similar patterns.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.614-618
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• 1992

The batch and fed-batch cultivations of Brevibacteriurn CHI were carried out for the production of nitrile hydratase. In batch culture, with pH control the cell mass and the specific activity increased more 20% and 30%. respectively. The maximum growth rate was obtained at a glucose concentration of $20g/{\ell}$ because of substrate inhibition. The fed-batch culture of Brevibacteriurn CHI with constant substrate feeding gave a cell density of up to $68g/{\ell}$ and nitrile hydratase activity was maintained at above 6.1units/mg. The cell growth yield on carbon .source was ca. 0,68 g/g glucose consumed. The total nitrile hydratase activity in this fed-batch mode increased up to 414.8 units/m${\ell}$, which amounted to 4.4 times that of the batch culture.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.70-76
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• 2003

Continuous anaerobic hydrogen production with a mixed culture was investigated. With a sucrose concentration of 5g COD/L in the feed, hydrogen production exceeded $0.5mole\;H_2/mole\;hexose$ was found at the early stage, however it did not maintain longer than 9days. It was assumed that the failure was caused by insufficient active hydrogen producing bacteria in the reactor. Therefore, effects of pH control, repeated heat treatment and substrate concentration on sustainable continuous anaerobic hydrogen production was examined to find out operating conditions to sustainable hydrogen production. Decrease of hydrogen production was not overcome by only pH control at 5.3. Repeated heat treatment could recover hydrogen producing activity without any external inoculum supply. However, frequent heat treatment was needed because the treated sludge also showed the tendency in decrease of hydrogen production. With a sucrose concentration of 30g COD/L in the feed, hydrogen production maintained $1.0-1.4mole\;H_2/mole\;hexose$ in continuously stirred tank reactor and $0.2-0.3mole\;H_2/mole\;hexose$ in anaerobic sequencing batch reactor) for 24days. More than 90% of soluble organics in effluent was organic acids, in which n-butyrate was the most one.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.105-113
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• 2003

Successful operation of a reactor can be accomplished when it is operated at proper D depending on the state of degradation. Operation at high D leads to the washout of biomass in the reactor while operation at low D leads to product inhibition due to the accumulation of excess VFA. These appear to limit the production of hydrogen to reach a higher level. Operation by D control was performed to improve the efficiency of hydrogen fermentation of food waste. Although simple organic matters were rapidly degraded in the early stage (day 1-2), proper VFA concentration and pH values were kept in the reactor at D of $4.5d^{-1}$, which was previously reported to be optimum initial D. High butyrate/acetate (B/A) ratios over 3.2 were obtained. Without D control, the reduction of simple organic matters after day 2 caused the decrease of VFA production and the increase of pH. Hydrogen production also decreased, as microbial proliferation was less than microbial loss by washout. However, the reactor performance was dramatically improved at D control from 4.5 to $2.3d^{-1}$. It showed the highest B/A ratios over 2.0 among the reactors on day 4-7. The second hydrogen peak appeared on day 4, resulting in the highest fermentation efficiency (70.8%) among the reactors. It was caused by the enhanced degradation of slowly degradable matters. The COD removed was converted to hydrogen (19.3%), VFA (36.5%), and ethanol (15.0%). Therefore, the strategy using D control, depending on the state of degradation, was effective in improving the efficiency of hydrogen fermentation.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.89-94
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• 1998

Various Mn-oxides can oxidize Cr(III) to Cr(VI). Behaviors of chromium species in the oxidation system, especially on the oxide surface, are expected to control the reaction. During Cr(III) oxidation by birnessite and pyrolusite, Cr species in the reaction system were determined to elucidate their effects on the oxidation. Capacities of Cr oxidation of the two Mn-oxides were quite different. Solution pH and initial Cr(III) concentration also had significant effects on the Cr(III) oxidation by Mn-oxides. Chromium oxidation by pyrolusite was less than 5% of the oxidation by birnessite. The high crystallinity of pyrolusite could be one of the reasons and the difficulty of Cr (III) diffusion to the positive pyrolusite surface and Cr(VI) and Cr(III) adsorption seems to be other controlling factors. At pH 3, adsorption or precipitation of Cr species on the surface of birnessite were not found. Small amount of Cr(VI) adsorption was found on the surface of pyrolusite, but arty Cr precipitation on the oxide surface was not found. Therefore Cr(III) oxidation at pH 3 seems to be controlled mainly by the characteristics of Mn-oxides. Chromiun oxidation by Mn-oxides is thermodynamically more favorable at higher solution pH. However as solution pH increased Cr oxidation by birnessite was significantly inhibited. For Cr oxidation by pyrolusite, as pH increased the oxidation increased, but as Cr(III) addition increased the reaction was inhibited. Under these conditions some unidentified fraction of Cr species was found and this fraction is considered to be Cr(III) precipitation an the oxide surface. Chromium(III) precipitation on the oxide surface seems to play an important role in limiting Cr(III) oxidation by armoring the reaction surface on Mn-oxides as well as lowering Cr(III) concentration available for the oxidation reaction.

• KSBB Journal
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• v.10 no.4
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• pp.441-448
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• 1995

Optimized fermentation medium and cultural conditions for the production or exopolysaccharide KS-1 with Bacillus polymyxa KS-1 was following as; 30g g1ucose, 2.59g yeast extract, $2.5g KH_2PO_4, 0.5g NaCl, 0.3g MgSO_4.7H_20, 0.1g CaC0_3 0.05g, FeSO_4.7H_2O, and 0.05g MnS0_4 . 4H_20in 1 liter distilled water. The exopolysaccharide production was influenced by the by the temperature and pH, the optimal conditions for the production of exopolysaccharide KS-1 seemed to be $30^{\circ}C$ and pH 7.0, respectively. About $10.3g/\ell$ of maximum exopolysaccharide was obtained al the initial pH 7.0, $30^{\circ}C$, 2vvm of aeration rate and 400 rpm of impeller speed in a jar fermentor.