• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1619-1627
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• 1999

Microbiological characteristics of gamma irradiated low salt squid Jeot-gal were examined. Following the fermentation periods, total bacterial cell, Lactobacillus spp., Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and yeast cell number were counted on their selective media and some acid forming bacteria and Pseudomonas spp. were identified. As the gamma irradiation dose increased, the microbial density of early fermentation phase was reduced and the growth rate was delayed. The repression effects on microbiological growth by gamma irradiation were to be higher as salt concentration increased. Adequate conditions of salt concentration and gamma irradiation for low-salt squid Jeot-gal preparation were 10% and 10 kGy, respectively. Lactobacillus sp. 2, Micrococcus varians and Streptococcus sp. I were isolated from 5% salt containing squid Jeot-gal, and Micrococcus morrhuae was from 20% only while Lactobacillus plantarum and Lactobacillus brevis were widespread. Lactobacillus brevis, Pediococcus halophilus and Pseudomonas diminuta were sensitive and Lactobacillus plantarum, Micrococcus morrhuae and Pseudomonas sp. 3 were resistant to gamma irradiation. The diversity of microflora decreased as salt concentration decreased and gamma irradiation dose increased.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1596-1603
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• 1999

Dongchimi (Korean-style fermented radish with juice) products were frozen to prevent further acidification and softening of texture by restraining microbial growth and enzyme activity during storage. Dongchimi juice and radish were separated prior to freezing process. Dongchimi radish was frozen at $-20^{\circ}C,\;-70^{\circ}C$ and immersed in liquid nitrogen and dongchimi juice was frozen at $-20^{\circ}C\;and\;-70^{\circ}C$. Frozen dongchimi samples were thawed with ambient temperatures of $4^{\circ}C\;and\;27^{\circ}C$ and with 915 MHz-microwave, respectively. Dongchimi radish immersed in liquid nitrogen and thawed with 915 MHz-microwave showed the highest pectinesterase activity and hardness, and the lowest polygalacturonase activity and color change, indicating that this quick freezing-quick thawing method can be used for the long-term storage of dongchimi products. Dongchimi juice frozen at $-70^{\circ}C$ and thawed with 915 MHz-microwave retained its pH and titrable acidity, and showed a largest reduction in total aerobic count and lactic acid bacteria.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.155-160
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• 2008

Ginsenosides have been regarded as the principal components, responsible for the pharmacological and biological activities of ginseng. Absorption of major ginsenosides at the gastrointestinal tract was extremely low, when ginseng taken orally. In order to improve the absorption and bioavailability, transformation of major ginsenosides into more active and valuable minor ginsenoside is much required. In this present study, We isolated a lactic acid bacteria Leuconostoc fallax LH3 from the Korean fermented food Kimchi, which have higher ${\beta}$-glucosidase activity. Using the ethanol precipitated curd enzyme of Leuconostoc fallax LH3, we investigated the biotransformation of ginsenoside Rd at different experimental condition to increase transformation. The maximum convertion was supported at 30 $^{\circ}C$ and decreased when temperatures increased. In order to optimize the effect of pH, the curd enzyme was mixed 20 mM sodium phosphate buffer (pH 3.5 to pH 8.0). Ginsenoside Rd was almost hydrolyzed between pH 7.0 and pH 9.0, but not hydrolyzed above pH 10.0. Ginsenoside Rd was hydrolyzed after 24 hrs incubation, but whereas the ginsenoside F2 was appeared from 36 hrs, and all ginsenoside Rd was transformed to F2 after the 60 hrs incubation. Based on this study, the curd enzyme of Leuconostoc fallax LH3 transformed the ginsenoside Rd at the 30$^{\circ}C$ and the pH optimum of 7.0 to 9.0 after the 60 hrs incubation time.

• Membrane Journal
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• v.13 no.2
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• pp.65-72
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• 2003

This study was focused on the investigation of filtration characteristics of membrane-coupled fermentor system for dissolved organics recovery from liquid organic sludge. On the filterability of MF over the range of $0.1{\sim}5 {\mu}m,$ the magnitude of total membrane resistance ($R_t$) is ranged as follows in the order; $0.1 {\mu}m>0.2{\mu}m>0.5 >1{\mu}m>2{\mu}m>5{\mu}m$. The cake layer resistance ($R_c$) occupied about 68~88% of total resistance with fermented sludge. Permeation flux decline was mainly attributed to the $R_c$, which was formed by a strong deposition from physico-chemical interactions of solids on membrane surface. Higher suspended solids (SS) concentration of suspension caused lower permeation flux. However, there was not a proportion relation beyond a certain SS concentration. The cross-flow velocity on the membrane surface was faster, which resulted in the higher permeation flux and also more efficient with low trans membrane pressure (TMP) in viewpoint of energy efficiency. The appropriate pH of suspension was over the range of 5.0~6.0 for dissolved organics recovery as well as the permeation flux. It is possible f3r bacteria to be separated perfectly with $0.1{\mu}m\; and \;0.2{\mu}m$ membrane pore size. Based on experimental results, most appropriate membrane pore size for the recovery is believed to around $1{\mu}m$.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.364-368
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• 1997

The vitamin C contents in Mulkimchi (watery kimchi prepared with Yulmoo, leaf radish) were analyzed during its fermentation and storage at 30$^{\circ}C$, 15$^{\circ}C$ and 4$^{\circ}C$, respectively. The total amount of vit. C in Mulkimchi fermented for 1 day at 30$^{\circ}C$ was rapidly increased to the highest level of 20 mg％. At this time, Mulkimchi showed pH 4.5 and 0.2% of total acidity expressed in lactic acid. The total microbes of the kimchi amounted to 10$\^$8/ cfu/$m\ell$ which are mostly found to be lactic acid bacteria. However, the amount of vitamin C in Mulkimchi was decreased gradually during the storage at 30$^{\circ}C$, 15$^{\circ}C$ and 4$^{\circ}C$ for 9 days. In the Mulkimchi fermentated at 15$^{\circ}C$, the maximum amount of vitamin C was 15 mg％ at 4 to 5 day-fermentation. The pH of this kimchi was 4.0 and its acidity was 0.15% as lactic acid. When the storage temperature was dropped to 4$^{\circ}C$ after 1 day-fermentation at 15$^{\circ}C$, its vitamin C didn't reach the above level after 9 day storage. As the fermentation temperature was kept at 4$^{\circ}C$, the content of vitamin C in Mulkimchi remained at 10 mg％ of its initial storage and didn't change through the 9 days storage.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.286-292
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• 1997

The purpose of this study was to investigate the effect of citron (Citrus junos) on Dongchimi (watery radish kimchi) fermentation. Dongchimi with various levels (0, 1, 2, 4, 6％) of citron was fermented at 10$^{\circ}C$ for 36 days. The pH of Dongchimi decreased slowly in all samples during fermentation, however, it was slightly lower in citron-added Dongchimi. Total acidity and turbidity of Dongchimi increased gradually during formentation, in which the level of increase was greater as the ％ of added citron increased. However, the total acidity and turbidity of Dongchimt without citron increased dramatically on 36$\^{th}$/ day of fermentation, and reached the values similar to those of Dongchimi with 6% citron. Reducing sugar content increased gradually up to 15∼23 days of fermentation and decreased rapidly for the rest of the period. The content of vitamin C was much higher in citron-added Dongchimi, and especially it was 4 times higher than that of without citron at the beginning of fermentation. The number of lactic acid bacteria reached the maximum on 15$\^{th}$/ day in citron-added Dongchimi and on 30$\^{th}$/ day in Dongchimi without citron, and decreased thereafter.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.29-35
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• 2013

Microbiological populations and the sterility of commercial powdered products treated with gamma irradiation at 0~10 kGy were investigated before using them as ingredients for a non-cooked Saengsik product. We evaluated a total of 14 powdered products: 8 powdered cereals, 3 powdered tubers, and 3 powdered leafy vegetables. The total numbers of bacterial populations in non-irradiated powdered cereals, tubers, and leafy vegetables were 2.7~6.9, 5.6~6.0, and $5.3{\sim}6.8\;log\; CFU{\cdot}g^{-1}$, respectively. Moreover, coliform bacteria were not indicated in adlay, millet, germinated brown rice, soybean, and mulberry leaves powder within detection limit ($2.0\;log\; CFU{\cdot}g^{-1}$). The number of Bacillus cereus exceeded $3.0\;log\; CFU{\cdot}g^{-1}$ (the maximum limit for Saengsik products) in all samples, excluding perilla seeds, buckwheat, barley, oat, potato, and Jerusalem artichoke powder. However, a dose of 6 kGy of gamma irradiation reduced the microbiological populations in all samples, and all the powdered products met the microbial requirements for Saengsik products. Futhermore, it was confirmed that all microorganisms in the 9 powdered products, except fermented brown rice, sweet potatoes, and 3 leafy vegetables, were sterilized by 10 kGy of gamma irradiation.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.473-479
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• 2019

The purpose of this study was to investigate the storage stability of liquid stick packs containing concentrated and steam-dried ginseng berry. Storage stability of liquid stick packs was determined during storage at 10, 25 and $35^{\circ}C$ for 4 months. The pH was decreased from 4.81 to 3.81 after 4 months at $35^{\circ}C$ while the acidity and solubility were not changed during storage of 4 months. The DPPH radical scavenging activity was decreased during storage at $35^{\circ}C$ after 4 months. The Hunter L and yellowness (b) values decreased while the redness (a) was not changed during storage after 2 or 3 months. The total amount of six ginsenosides including Rg1, Rb1, F2, Rg3(S), Rg3(R), and Rg5 was not changed after storage of 4 months at 10 and $25^{\circ}C$. Neither bacteria nor coliforms were not detected during storage of 4 months. Considering quality parameters, significant changes were observed in color parameters L and b, while all others remained unchanged during 4 months stored at 10 and $25^{\circ}C$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.3
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• pp.213-218
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• 2021

In this study, Kombucha, a fermented drink by adding beneficial bacteria to green tea or black tea with sugar, was classified using column chromatography, and the presence or absence of quercetin glycoside, a type of flavonoids, was confirmed through TLC. In addition, the anti-pollution effect of protecting and improving the skin from pollution was confirmed using the fraction. Keratinocytes were treated with K-QG to confirm the cell viability, showing a survival rate of 90% or more up to a concentration of 100 ㎍/mL, and the cell viability by benzo[e]pyrene and fine dust stimulation to see the anti-pollution effect was measured. At 100 ㎍/mL, the improvement rates were about 68.79% and 50.68%, respectively. In addition, as a result of confirming the expression of AhR activated by benzo[a]pyrene through Western blot, it showed an inhibition rate of about 31.08% at 100 ㎍/mL compared to the control group. Through the results of this study, K-QG is thought to be valuable as an anti-pollution functional material, protecting and improving skin irritated from benzopyrene and fine dust.

• Food Engineering Progress
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• v.13 no.1
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• pp.16-23
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• 2009

Onion juices supplemented with different concentrations of puffed red ginseng extract were fermented using Pediococcus pentosaceus KC-007 and their biologically functional properties were investigated. When onion juices were supplemented with puffed red ginseng extract at the concentration of 0.5, 1, 2, and 4% (v/v) each, viable cell number of lactic acid bacteria was the highest at 24 hr of fermentation in all samples. The titratable acidity increased as the fermentation proceeds irrespective of the added amount of red ginseng extract, and the pH of fermentation broth decreased until 36 hr of fermentation. The reducing sugar of fermentation broth decreased until 24 hr of fermentation and did not change thereafter. The electron donating ability and nitrite scavenging ability were highest when red ginseng extract was added at the concentration of more than 1% (w/v). The overall acceptance in sensory evaluation was the best when red ginseng extract was added at the concentration of 1% (w/v). From these results, it is confirmed that the optimum concentration of puffed red ginseng extract for the lactic acid fermentation of onion juice was 1% (w/v).