• KSBB Journal
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• v.23 no.3
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• pp.276-280
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• 2008

In this study, the productivity of bioethanol obtained from various domestic raw materials (barley, brown rice, corn and sweet potato) by simultaneous saccharification and fermentation (SSF) process was estimated. Also, optimal conditions of temperature, time and enzyme concentration in gelatinization and liquefaction process were investigated. As a result, corn showed high ethanol yield of 90.45% and sweet potato had a rapid fermentation time. Productivity of bioethanol increases in accordance with the starch value of raw materials except brown rice. Therefore, it is very important to understand the structure of starch. Further studieson the characteristics of raw materials are necessary to enhance the productivity of bioethanol.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.207-211
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• 1997

Media optimization for the production of thermostable protease specifically hydrolyzing defatted soybean meal (DSM) from Bacillus licheniformis NS70 was performed by two methods, one-at-a-time method and response surface methodology (RSM). The best carbon source and nitrogen source for the protease production were lactose and DSM, respectively. The maximum protease production estimated by RSM was 606 U/L at 1.11% lactose and 0.43% DSM, the value of which was nearly consistent to the experimental value of 599 U/L. Yeast extract suppressed the protease production. The medium pH was slightly increased at the beginning stage of fermentation, and it tended to decrease after 8 hours. The optimal pH for the protease production was 7.2 in the batch fermentation.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.11-22
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• 2007

This aims to review natural products transformed by mimic intestinal metabolisms with microorganisms and hydrolytic enzymes, which exhibit enforced biological activity, higher extraction yield and identification of active components. In the process, transformation to the smaller active compounds with enzymes and microbes mimics the pharmacological action of natural products by intestinal bacteria. In order to establish conditions for the fermentation and enzyme reaction, it is required to choose several natural products for biotransformation and investigate the optimal conditions for the fermentation or the enzyme reaction such as composition, temperature, pH, inoculum, and cultivation time. It is expected an increase of the internal absorption of the active materials without regard to the intestinal microbes or its ability through biosynthesis of the active materials by the microbes and enzymes. And this techniques can be applied to biotransformation of natural products such as sesaminol, resveratrol, 1-deoxy nojirimycin, naringenin, quercetin, and baicalin and to the metabolism study using the animal model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.167-174
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• 2003

Physicochemical and sensory properties of turnip dongchimi were examined during fermentation at $0^{\circ}C$. Salt concentrations of dongchimi liquid were around 1.3% during fermentation. Greater decrease in pH and reducing sugar content in solid, and higher increase of acidity, turbidity and reducing sugar content in liquid were observed during fermentation. The acidity and pH at the optimal fermentation time, at the day 40 was observed 0.36% and pH 3.9, respectively Lactobacilli number, turbidity, anthocyanin content, the Hunter color L and a values were the greatest at the day 40 and then gradually decreased. The hardness and fracturability of turnip, determined by texture analyser, decreased during fermentation, while springiness increased. Sensory evaluation showed that the scores of color of purple, sweet taste, savory taste, and over-all preference of dongchimi were highest at the day 40. Score of overall preference of turnip dongchimi was the highest with 6.5 at the 40th day of fermentation, the optimum fermentation time, but the score until the day 60 was not significantly decreased.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.432-437
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• 2007

In this study, we examined the conditions for an auto-aging system placed within a kimchi refrigerator for optimal fermentation, and to prolong the storage time of kimchi. Various characteristics of kimchi fermented at different temperatures ($5-23^{\circ}C$) were compared. We observed that the higher the fermentation temperature, the less desirable the overall acceptability of the product. To establish the time point in which to convert the fermentation mode to the storage mode, kimchi was stored at $-1^{\circ}C$ for 1 week once it reached the designated acidity (0.4, 0.6, and 0.8%). The results indicated that the lower the kimchi acidity, the higher the sensory score. The storage temperature of $-1^{\circ}C$ was not low enough to retard microorganism growth completely; however, the kimchi stored at $-2{\pm}0.5^{\circ}C$ became frozen. Accordingly, $15^{\circ}C$ and $-2{\pm}0.5^{\circ}C$ are suggested as the fermentation and storage temperatures for the kimchi refrigerator, respectively. A kimchi acidity of 0.4% can be used as an index for the time point to convert fermentation to storage. Subsequently, the time required for the fermentation course can be calculated based on this.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.596-603
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• 2019

This study involved the production of specialty lager beers supplemented with Korean red ginseng extracts or Bokbunja (Korean black raspberry, Rubus coreanus Miquel) juice. The effects of the Korean red ginseng extracts or Bokbunja juice on the specific gravity, pH, yeast viability, free amino nitrogen content, reducing sugar content, color, alcohol content, turbidity, and sensory evaluation were evaluated. The alcohol content of the beers containing the extracts or juice were within the standard alcohol amounts (3.63-4.0%, v/v). The pH values of the three samples containing Bokbunja juice were lower than that of the control values. The sensory evaluation showed that the addition of Bokbunja juice was superior to the ginseng extracts, and the optimal addition time was before or after the secondary fermentation. These data indicate that the flavor and odor of the Bokbunja juice are more persistent than that of the ginseng extracts.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.66-70
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• 1997

A mixed-culture of Gluconobacter suboxydans IFO 3172 and Saccharomyces uvarum IFO 0751 was per-formed in a synthetic medium. the optimal inculum ratio of G. suboydans and S. uvarum for mixed-culture fermentation was 150:1. The optimum pH, incubation temperature and aeration rate for mixed-culture fer- mentation were 5.0, 3$0^{\circ}C$ and 2.25vvm, reapectively. As a result of batch pure-and mixed-culture fer-mentation, specific growth rate in pure-culture of both strain was lower than that in mixed-culture. The yield of cell mass from S. uvarum exclusively decreased. The growth rate of the mixed-culture was very similar to the pure-culture in the begining of culture, but it has been decreased after 16hrs. In the mean time, S. uvarum in mixed-culture fermentation could grow due to fructose converted, but it could not row in pure-culture fermentation. Thus, the relationship was a sort of commensalism. The kinetic parameters cal-culated through steady-state results during continuous fermentations are as follows :{TEX}$$\mu$_{max1}${/TEX}=0.118({TEX}$h^{-1}${/TEX}), {TEX}$Ks_{1}${/TEX}=0.330(g/L),:{TEX}$$\mu$_{max2}${/TEX}=0.162({TEX}$h^{-1}${/TEX}), {TEX}$Ks_{2}${/TEX}=0.038(g/L). The yield of bacterial cell mass relatively constant, but yield of yest cell mass was gradually decreased.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.5
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• pp.569-575
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• 2017

The purpose of this study was to investigate the physicochemical and sensory characteristics and overall preference for makgeolli after conducting fermentation using carrots with various levels of beta carotene and functional materials. The beta - carotene content was highest in 16% carrot powder, and steadily increased as the amount of carrot powder increased. Alcohol content increased with increasing amount of carrot powder. Alcohol content which greatly influences the quality of traditional wine, changes depending on the water soluble solid content and free sugar content during the manufacture of traditional wine. Sensory tests showed that the highest results were in the 12% carrot powder added group. As a result, the content of beta carotene increased with the addition of carrot powder, but the fermentation time was delayed and the sugar content was decreased because of variations in sugar content and color. Therefore, the optimal addition of carrot powder was 12%.

• KSBB Journal
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• v.6 no.4
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• pp.369-377
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• 1991

The effects of nitrogen sources(sodium glutamate and peptone) on the production of xanthan gum were investigated. The fermentation using sodium glutamate as a nitrogen source is longer than that of peptone. In the initial nitrogen concentration of 0.4-1.0g/L, Bs was about 2.0 and ${\beta}$s was 1.2. The optimal yields were obtained when the carbon source/nitrogen concentration was 10-16. The fermentation time and product yields in the fermentation medium of mixed nitrogen source [sodium glutamate-N(0.75g/L)+peptone-N(0.25g/L)] were similar to those of peptone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.542-550
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• 2016

This study was carried out to investigate the optimal processing conditions for odor removal and maximal antioxidant effects of oyster (Crassostrea gigas) hydrolysate. The optimal hydrolysis conditions were 3.3% neutrase as the protease, $50^{\circ}C$ as the hydrolysis temperature, and 8.3 h as the hydrolysis time. Fish odor of enzymatic oyster hydrolysate was greatly reduced during Saccharomyces cerevisiae fermentation at $24^{\circ}C$ with 0.5% glucose. The protein content of the fermentation product from oyster hydrolysate powder was 25.7%, which contained the major amino acids Glu, Asp, Lys, Arg, Gly, and Ala, whereas Leu, Ala, Phe, Val, and Tau were abundant free amino acids. The important minor minerals were Zn and Fe. Toxicity against Chang cells was not observed in the fermentation product from the oyster hydrolysate up to $200{\mu}g/mL$. The results suggest that fermentation with S. cerevisiae could reduce the fish odor of enzymatic oyster hydrolysate. The hydrolysate has potential application as a food ingredients and nutraceutical.