• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.203-206
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• 1992

Conditions of fermentation for the production of demethyltetracycline were examined using the mutant, which was obtained through the cell fusion of demeclocycline producing strains, The optimum temperature and the initial pH of broth for demethyltetracycline fermentation were $25^{\circ}C$ and 6.7, respectively. Unlike any other cases, the control of pH with alkali solution during the fermentation process affected the productivity. As a general rule, the larger the inoculum size the higher the early consumption of sugar and the viscosity of broth, which means that fermentation proceeds more rapidly as the inoculum size is increased. The highest productivity was shown when the inoculum size was 5% (v/v), and the phase of seed also influenced the fermentation. Among the parameters of pre-culture thus examined, pH was the most important factor.

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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• pp.62-67
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• 1997

To enhance the hyperproductive and low energy-consuming ethanol fermentation rate, the thermotolerant yeast S. cerevisiae RA-74-2 cells were immobilized. An efficient immobilization condition was proved to be $1.5{\%}$ (w/v) alginate solution, neutral pH and 20 h activation of beads. The fermentation characteristics and stability at various temperatures were examined as compared with free S. cerevisiae RA-74-2 cells. The immobilized cells had excellent fermentation rate at the range of pH 3-7 at 30-$42^{\circ}C$ in 15-$20{\%}$ glucose media. When the seed volume was adjusted to 0.12 (v/v) (6ml bead/50 ml medium), $11{\%}$ (w/v) ethanol was produced during the first 34 hand $12.15{\%}$ (w/v) ethanol [$95{\%}$ (w/v) of theoretical yield] during the first 60 h in $25{\%}$ glucose medium. In repetitive fermentation using a 2 litre fermentor, 5.79-$7.27{\%}$ (w/v) ethanol [76-$95{\%}$ (w/v) of theoretical yield] was produced during the 40-55 h in $15{\%}$ glucose media. These data suggested the fact that alginate beads of thermotolerant S. cerevisiae RA-74-2 cells would contribute to economic and hyperproductive ethanol fermentation at high temperature.

• Journal of the Korean Society of Food Culture
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• v.11 no.5
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• pp.601-608
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• 1996

Fermentation characteristics of Baikhaju (a typical Korean traditional alcoholic beverage) were investigated during fermentation with differently treated rice samples, which were steamed rice (SR), plain steamed rice bread (RB), rice porridge (RP) and roasted rice (RR). The RB sample showed an excellent fermentation efficiency with the highest alcohol production (20.84%). The SR and RR samples showed 17.79% and 17.31% of alcohol production, respectively. The RP sample was the lowest alcohol production (11.47%). The pH values of all the beverage samples were similar and were ranged from 3.6 to 3.9. The fermentation periods of RB and RR samples were longer than the SR and RP. The inner temperature and microbial growth in all the beverages increased at each of input steps of the rice and Nuruk (a Korean-style bran koji). Fusel oil content of the SR and RP samples (613.6 ppm) was higher than that of RR (482.7 ppm). The RB sample with the best fermentation efficiency had the lowest fusel oil content (341.8 ppm). The RP sample showed the highest score in sensory evaluation and RB sample showed the lowest. The results on sensory evaluation were contrary to those on the fermentation efficiency.

• Journal of the Korean Society of Food Culture
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• v.6 no.3
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• pp.245-249
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• 1991

This study was conducted to establish traditional manufacturing process of Hongju, a traditional spirit by traditional Kokja and Koji method based on different materials. In the fermentation process, the changes of temperature, pH, total acid, alcohol, total sugar and microflora in mash were analyzed. During the whole fermentation period, the temperature in mash made by Kokja method was reached to $30^{\circ}C$, and that of Koji method was reached $33^{\circ}C$. There was no significant difference in pH by different treatments and the initial pH in Koji method was pH 6.0 and the final pH was 4.0. The content of total acid was higher in mash processed by Kokja method than that of Koji method. Alcohol content was higher in mash processed by Koji method. The content of total sugar in all samples were reduced gradually according to progress of fermentation. Yeast populations in all samples were increased up to 6 days of fermentation and then decreased gradually. Lactic acid bacteria were increased until 3 days of fermentation and then decreased until the fermentation completed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1814-1818
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• 2010

The present study was carried out to elucidate the changes in the chemical characteristics of taurine added Kimchi during fermentation for 46 days at $6^{\circ}C$. Chinese cabbage was brined in a 10% salt solution for the control Kimchi and in a 10% salt solution containing 5% taurine for taurine added Kimchi (Taurine I, II, and III). One and three percent (w/w, based on Chinese cabbage) of taurine were added to make Taurine II and Taurine III, respectively. Reducing sugar and vitamin C contents for all the samples decreased after the 46-day fermentation. Taurine was not detected in the control, and the taurine contents, from the largest to the smallest, during the fermentation period were Taurine III, Taurine II and Taurine I. Amino nitrogen contents in all the samples studied proportionally increased during the 46-day fermentation. It is suggested that taurine does not affect the chemical characteristics of Kimchi during fermentation at low temperature ($6^{\circ}C$).

• Food Science and Biotechnology
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• v.16 no.6
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• pp.1011-1017
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• 2007

Saeujeot (salted and fermented shrimp) and kimchi are traditional Korean fermented foods. Even though shrimp have often induced severe allergic reactions in sensitized individuals, few studies have investigated the allergenicity of shrimp. The aim of this study was to observe the changes of pH and allergenicity of raw shrimp (Acetes japonicus) and saeujeot in cabbage kimchi during fermentation using competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). Fermentation was carried out at different temperatures (25, 15, and $5^{\circ}C$). The pH of cabbage kimchi added with raw shrimp or saeujeot slowly decreased at lower temperature ($5^{\circ}C$) at the end stage of the fermentation process. The binding ability of serum obtained from patients allergic to raw shrimp against shrimp tropomyosin and saeujeot in kimchi rapidly decreased during longer fermentation periods and higher temperature ($25^{\circ}C$). In conclusion, the allergenicity of both raw shrimp and saeujeot in kimchi decreased during fermentation but the decrease in allergenicity of saeujeot was greater than observed for raw shrimp.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1552-1558
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• 2021

The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic Escherichia coli (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25℃, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera Lactobacillus, Leuconostoc, and Weissella were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic E. coli (ETEC).

• 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 Industry Convergence
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• v.22 no.1
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• pp.61-69
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• 2019

All the parts of lotus, including the seed, rhizome, leaf, stalk, petal, anther, pericarp, and fruit receptacle, have been used in traditional medicine system as a health beneficial supplement. However the most usually used from lotus plant is only the root. Therefore in this study, it will be discussed more the utilization of other parts of the lotus, namely the flower of lotus. The petals and stamens of lotus actually are also rich in bioactive components such as flavonoids and alkaloids, are used in the treatment of tissue inflammation, cancer, skin disease, and also for us as antidotes. One of the biotechnological process that can be used to improve the nutritional content, sensory, and also antioxidant activities is fermentation process. The final product desired from the fermentation process in this study is vinegar. The microbial strain powder used is Uinkin fermented powder with three variations of fermentation. The variations given in this study were initial sugar 32%, 24%, and 14% with the same fermentation temperature, $35^{\circ}C$ for 3 months. The results obtained showed that the pH value and sugar content of products during the fermentation process were decreasing during the fermentation process, with total polyphenol content of $283.7{\pm}97.6mg/100g\;QAE$, and total flavonoid content of $3.3{\pm}0.0mg/100g\;QAE$. For the DPPH radical scavenging ability of the fermentation product also increased in a concentration dependent manner, with ORAC activity of the product showed a high activity of $20.7{\pm}0.41{\mu}M$ TE. Therefore, fermentation process can be the one of method for improving the product. The efficiency of lotus flower vinegar fermentation can be reached with an initial sugar condition of 25% (sample B).

• Culinary science and hospitality research
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• v.7 no.1
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• pp.91-105
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• 2001

Chou-cream bread and Red bean paste bread were made by sponge & dough method with the sweet dough formula. The bread quality was studied by the measurements of the temperature variation, the fermentation level of frozen dough in the special condition(dough conditioner of 5$^{\circ}C$, 10$^{\circ}C$, 15$^{\circ}C$, 20$^{\circ}C$ and 30$^{\circ}C$), the product volume and thesensory evaluation with frozen dough thawed, fermented and baked. When thawing temperature was low, the core temperature of frozen dough increased slowly and the time for thawing and fermentationwas long. In thawing and fermentation, the core temperature of Red bean paste dough increased faster than that of Chou-cream dough. When the thawing conditions of dough conditioner(retarder) were 20$^{\circ}C$ and 30$^{\circ}C$, the level of total time decrease for thawing and fermentation was 55 and 86 min in Chou-cream dough and 62 and 90 min in Red bean paste dough respectively in comparison to dough conditioner of 5$^{\circ}C$. In volume of baked products, they showed no significant difference for three weeks of storage, but slight difference for four weeks of storage. The result was that Chou-cream bread was larger than Red bean paste bread in the decrease of volume. In sensory evaluation, the bread quality became low according to the time. When stored for four weeks in the freezer, significant differences were found in Chou-cream vread, but slight difference appeared in Red bean paste bread. The research identified that Red bean paste dough was more effective in manufacturing time than that of Chou-cream dough, when thawing temperature was high, and if frozen dough was thawed in the retarder of lower than 20$^{\circ}C$, the bread quality in terms of volume and sensory evaluation had no significant difference in comparison to the none-freezing Red bean paste bread.