• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.560-564
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• 2013

${\small{D}}$-Ribose is a value-added five-carbon sugar used for riboflavin production. To investigate the effects of oxygen supply and mixed sugar concentration on microbial production of ${\small{D}}$-ribose, a transketolase-deficient Bacillus subtilis SPK1 was cultured batch-wise using xylose and glucose. A change of agitation speed from 300 rpm to 600 rpm at 1 vvm of air supply increased both the xylose consumption rate and ${\small{D}}$-ribose production rate. Because the sum of the specific consumption rates for xylose and glucose was similar at all agitation speeds, metabolic preferences between xylose and glucose might depend on oxygen supply. Although B. subtilis SPK1 can take up xylose and glucose by the active transport mechanism, a high initial concentration of xylose and glucose was not beneficial for high ${\small{D}}$-ribose production.

• 한국식품영양학회지
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• 제26권3호
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• pp.358-365
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• 2013

The study was conducted to investigate the condition for mixed fermentation of Rhodilola sachalinensis with red ginseng using Lactobacillus acidophillus 128 and the changes of physicochemical properties and antioxidant activities before and after the lactic acid fermentation was examined. In the single fermentation of Rhodiola sachalinensis extract, the pH and titratable acidity rarely changed, and the number of lactic acid bacteria decreased greatly. On the other hand, in the lactic acid fermentation of Rhodiola sachalinensis-red ginseng mixed extract of 50% red ginseng content, the pH decreased, whereas the titratable acidity and the number of lactic acid bacteria increased. The solid content of optimal mixed extract for lactic acid fermentation was 0.5%. Sugar content decreased during fermentation, but total phenolic compounds tended to increase during fermentation. The salidroside and p-tyrosol content of the initial Rhodiola sachalinensis-red ginseng mixed extract was 419.5 mg% and 60.1 mg%, respectively; after fermentation, the salidroside content after lactic acid fermentation decreased greatly to 81.8 mg%, and the amount of p-tyrosol increased greatly to 324.9 mg%. The DPPH scavenging activity of Rhodiola sachalinensis-red ginseng mixed fermentate was 78.1% at 0.1% concentration, showing a tendency to increase as compared to 50.3% of Rhodiola sachalinensis-red ginseng mixed extract before the fermentation (p<0.05); it was a higher antioxidant activity as compared to the single fermentation of Rhodiola sachalinensis or red ginseng.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1065-1070
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• 1998

Lactic acid bacteria KL 1, KD 6, KL 4 strains isolated from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for mixed culture fermentation 3 days at 3$0^{\circ}C$, and then their chemical changes were studied during fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 days) or 0.58%(1 day) and with the final pH of 3.3(3 days) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. The contents of vitamin C and carotene were retained and stabilized as 70~80% level of their initial values after 24 hrs fermentation. And also ethanol was produced as of the range in 9.6mg%(W/V) by the mixed culture fermentation of KL 1 and yeast, however, the content of ethanol in single culture fermentation by KL 1 strain was much lower than that of mixed culture. The major components of organic acids in fermented juice by mixed culture were considered as malic(26.0%), lactic(49.9%), succinic and citric acid, whereas these of unfermented juice were malic(53.2%), citric and other acids. On other hand, reducing sugar was decreased from 18.3mg/ml in fresh juice to about 12mg/ml in juice by mixed culture fermentation. Concentrations of fructose, glucose and sucrose were also greatly reduced in fermented juice.

• 한국미생물·생명공학회지
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• 제27권2호
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• pp.145-152
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• 1999

Brettanomyces custersii CBS 5512 which has reported as a thermotolerant glucose-cellobiose co-fermentable yeast strain was mutated with UV and NTG to improve ethanol yield at higher than 4$0^{\circ}C$ B. custersii H1-23, H1-39, H1-55 and H1062 were finally selected for hyper-fermentable strains at higher than 4$0^{\circ}C$ from thermotolerant 7510 colonies through 5th selection. Among the selected strains, H1-39 mutant had better fermentability at 4$0^{\circ}C$ and 43$^{\circ}C$ from different concentrations of glucose. H1-39 and H1-23 mutants yielded more than 70% of the theoretical ethanol yield in 4 and 8% mixed sugars at above 4$0^{\circ}C$, which was 5-11% higher than those by original strain. Especially, H1-39 mutant had better fermentability in 4% mixed sugar. It showed 78.5% of the theoretical yield at 4$0^{\circ}C$ and 72.2% of the theoretical yield at 43$^{\circ}C$. On the other hand, theoretical yield of ethanol by H1-39 mutant in 8% mixed sugar at 4$0^{\circ}C$ and 43$^{\circ}C$ were 75.2% and 70.2%, respectively. Theses values increased up to 7-11% as compared to those by orginal strain. By the simultaneous saccharification and fermentation, ethanol production by H1-39 mutant increased up to more than 23% as compared to that by original strain.

• 한국미생물·생명공학회지
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• 제20권1호
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• pp.91-95
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• 1992

Xylose와 cellobiose를 모두 발효할 수 있는 효모를 선발한 결과 Pichia stipitis CBS 5775와 5776이 가장 우수하였다. P.stipitis CBS 5776은 glucose, xylose 및 cellobiose에서 각각 0.4, 0.36 및 0.23g/g substrate의 에탄올 수율을 나타내었다. 혼합당에서의 발효 결과 glucose는 xylose와 cellobiose 이용에 대하여 catabolite regulation을 일으켜서 glucose가 다 소비된 후에 다른 기질이 소비되었다. 그러나 xylose와 cellobiose는 동시에 소비되었다. 혼합기질에서의 에탄올 수율은 단일기질에서의 각각의 수율의 합과 거의 유사하였다.

• 한국식생활문화학회지
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• 제31권4호
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• pp.348-356
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• 2016

The purpose of this study was to investigate the chemical contents (sugar, nitrogen, and amino acids) and sensory characteristics of traditional soy sauce according to three different methods. The samples were taken from four different periods (0, 20, 40, and 60 days after fermentation). Total sugar contents increased in all groups according to ripening period, and Gyupjang (G) showed the highest sugar content among the groups. Total nitrogen and amino acid contents of all groups increased after 60 days of ripening, and Gyupjang (G) and Gyupjang mixed with salt water (SG) had higher total nitrogen content compared to Chungjang (S) at the same period. The results from the sensory evaluation show that preferable sensory characteristics, such as color preferences, sweetness, umami taste, and overall preference, were significantly higher in Gyupjang (G) and Gyupjang mixed with salt water (SG) than in Chungjang (S). Preferable sensory characteristics had significantly high positive correlation with most amino acids, total nitrogen, and sugar contents, except for glutamine. Based on the significant difference in preferable sensory characteristics between Gyupjang mixed with salt water (SG) and Chungjang (S), Gyupjang mixed with salt water (SG) can be used to improve sensory characteristics. This research implies that adding salt water during the manufacturing Gyupjang process is advisable to yield high quality soy sauce.

• Preventive Nutrition and Food Science
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• 제16권2호
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• pp.142-149
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• 2011

The purpose of this study was to elucidate the physicochemical and microbiological properties of Korean traditional rice wine, Makgeolli, supplemented with black garlic extract during fermentation. Black garlic extract was diluted with distilled water to produce 0.5% and 1.0% black garlic solutions. Those solutions were then used to make rice solutions which included 2 kg rice, 40 g Nuruk (a fermentation starter), and 14 g yeast. After being mixed, the rice solutions were fermented for 7 days in a water bath at $28^{\circ}C$. The alcohol contents of the control, 0.5% and 1.0% black garlic Makgeolli were 16.9, 16.0, and 16.2%, respectively. Total acidity, total soluble solids, and color increased throughout the fermentation process. There was an increase of microorganisms throughout the fermentation period in all the samples. Glucose was the highest free sugar, and succinic acid was the highest organic acid detected in all the samples. Thirty nine volatile compounds were detected in black garlic Makgeolli.

• 한국식품조리과학회지
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• 제19권2호
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• pp.188-194
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• 2003

This study was conducted to investigate the effect of beef bone extracts on the organoleptic quality and fermentation of Baeck Kimchi. For this study, the organoleptic characteristics of Baeck Kimchi, with addition beef bone extracts were tested, and the changes in the fermentation factors, such as pH, acidity, reducing sugar and total microbial count, were observed during fermentation at 10$^{\circ}C$ and 20$^{\circ}C$. Greater amounts of lipids and soluble nitrogen were extracted to increasing the boiling time for the preparation of the beef bone extracts. However, 1% of the mixed beef bone extracts, prepared by boiling for 5, 7 and 9 hours, was the most acceptable for the Baeck Kimchi fermentation, as assessed from the results of sensory consumer tests. The beef bone extracts enhanced the umami taste of the unfermented Baeck Kimchi. The carbonated taste, sourness and fresh flavor of the fermented Baeck Kimchi were also enhanced. The fermentation rate was increased by the addition of beef bone extracts to Baeck Kimchi.

• 한국식품영양학회지
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• 제30권2호
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• pp.305-311
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• 2017

보리와 밀의 혼합막걸리 제조조건을 설정하기 위하여 발효온도(20, 25, $30^{\circ}C$)및 시간(3, 6, 9일)을 달리하여 제조한 혼합막걸리의 발효특성을 조사하였다. pH와 당도는 발효온도 및 시간이 증가함에 따라 전반적으로 증가하는 경향을 나타내었으며, 총산은 발효온도와 시간에 따라 비례적으로 증가하였다. 환원당과 알코올 함량은 발효온도 $20^{\circ}C$와 $25^{\circ}C$에서는 발효시간이 경과됨에 따라 환원당은 감소하고, 알코올은 증가하는 반면, 발효온도 $30^{\circ}C$에서는 발효 6일에 알코올 함량이 감소하였다. 색도는 L값은 대부분 발효온도가 증가함에 따라 감소하는 경향을 보였으며, a값과 b값은 발효 9일차에 발효온도에 따른 유의적 차이를 보이지 않았으나, 발효시간이 경과함에 따라 유의적으로 증가하는 경향을 나타내었다(p<0.05). 보리와 밀 혼합막걸리의 미생물수를 측정한 결과, 효모수는 발효 3일차에 발효온도 $20^{\circ}C$, $25^{\circ}C$ 및 $30^{\circ}C$에서 각각 8.14, 7.93 및 7.67 Log(CFU/mL)로 가장 높은 수준을 나타냈고, 발효시간 경과에 따라 감소하였다. 이것은 발효온도와 상관없이 총균수와 유산균수가 모두 동일하게 나타났다. 유기산 조성은 citric acid와 lactic acid가 대부분을 차지했으며, 그 외 malic acid와 pyruvic acid도 일부 검출되었다. 이상의 결과를 종합했을 때 보리와 밀 혼합막걸리의 최적 발효조건은 발효온도 $20{\sim}25^{\circ}C$에서 6일간 발효했을 때 우수한 막걸리를 제조할 수 있을 것으로 판단하였다.

• 한국식품과학회지
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• 제29권2호
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• pp.387-389
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• 1997

L. brevis, L. fermentum과 L. plantarum의 혼합젖산균을 사용하여 소다크랙커의 스폰지 발효과정 중에 밀가루와 당 농도가 미치는 양향을 살펴보았다. 밀가루 전분이 혼합젖산균에 의하여 포도당으로 전환되어 이용되므로 포도당을 밀가루 용액내에 첨가하여 실험을 수행하였다. 포도당 첨가할 경우 생성되는 총적정산도(TTA; total titrable acid)가 포도당을 첨가하지 않은 경우에 비하여 적게 증가하였고, pH 감소의 폭도 적었다. 이는 첨가된 포도당이 세포성장을 촉진시키고, 유기산의 생성을 억제하는 것으로 생각된다. 또한, 소다크랙커의 스폰지 발효과정 중에서 밀가루 농도가 증가할수록 생산되는 총적정산도는 증가되고 pH는 감소되었다.